Richard Roberts Publications & Presentations List
index

1988 / 1990 / 1991 / 1994 / 1995 / 1996 / 1997 / 1998 / 1999 / 2000- / Test Construction 1988   Published Papers Roberts, R. D., Beh, H. C., & Stankov, L. (1988). Hick's law, competing task performance and intelligence. Intelligence, 12, 2, 111-130. Recently, psychologists have attempted to relate individual differences in intelligence to differences in a participant's ability to divide attention. Researchers have also examined intelligence in relation to differences in the speed with which individuals process information offered by the environment. Because these approaches are not mutually exclusive and, indeed, have some important features in common, it was decided to examine the relationship between speed of processing and intelligence under conditions requiring divided attention. To this end, the Raven's Progressive Matrices Test was administered to 48 participants who subsequently performed a card-sorting task of varying information content under both single- and competing-task conditions. The obtained results point strongly to a more central role of cognitive complexity in speed of processing models of intelligence.   Conference Papers Roberts, R. D., Beh, H. C., & Spilsbury, G. (1988). Hick's law and competing task performance. Paper presented at The ACER Seminar on Intelligence, Sheraton Hotel, Melbourne, Australia, August, 1988. Participants (N = 72) completed a card-sorting task under single and competing conditions. Microstructural analyses revealed the presence of simplex patterns of correlation across information levels in both conditions. It was also discovered that mean performance in the competing condition was equivalent to adding one bit of information to single-task performance.   Stankov, L., Spilsbury, G., & Roberts, R. D. (1988). Difficulty manipulations with the four-term linear order reasoning task and its correlation with intelligence. Paper presented at The ACER Seminar on Intelligence, Sheraton Hotel, Melbourne, Australia, August, 1988. Microstructural analyses of Light, Zelinski, and Moore's (1982, Journal of Experimental Psychology: Learning, Memory, and Cognition, 8, 435-447) four-term series problem were conducted. Performance parameters extracted from this task were shown to share substantial correlation with fluid intelligence.   Roberts, R. D. (1988). Hick's law, multiple tasks and intelligence. Paper presented at Department of Psychology Colloquium, University of Sydney, Sydney, NSW, Australia, June, 1988. A conjoint measurement analysis of the competing card-sorting paradigm is reported on data collected from 24 participants. Independence, double- and triple-order cancellation conditions were satisfied, indicating that this divided attention measure likely has a quantitative structure. Correlations with a measure of fluid intelligence were found to be highest when the competing task was most cognitively demanding.   1990   Published Papers Spilsbury, G., Stankov, L., & Roberts, R. D. (1990). The effect of a test's difficulty on its correlation with intelligence. Personality and Individual Differences, 11, 10, 1069-1077. The main aims of this study were to: (a) explore the relationship between intelligence and working memory load in a verbal reasoning task (the four-term series problem), and (b) examine the relationship between speed and accuracy of performance on this task. Findings obtained with 83 participants indicate that increasing working memory demand influences task difficulty but does not lead to increasing correlation with central measures of intelligence. In addressing the second aim, a measure based on the ratio of mean number correct to mean solution time was derived. This is demonstrated to order difficulty levels in a psychologically meaningful way by, in particular, allowing an estimation of an individual's deviation latent ability that is independent from item difficulty. This deviation latent ability is shown to share higher correlation with fluid intelligence measures than either "raw" number correct or speed of response parameters.   Conference Papers Prichard-Levy, A., Roberts, R. D., & Beh, H. C. (1990). A generalized model of Hick's Law: Predicting complex choice reaction times. Paper presented at The XVIIth Australian Experimental Psychology Conference, Australian National University, Canberra, Australia, July, 1990. Many studies of choice reaction time (CRT) employ the Roth-Jensen experimental paradigm in testing Hick's law. This law states that the rate of information gain by human participants (as measured in bits per second) is constant regardless of available alternatives. The Roth-Jensen paradigm, however, is limited to tasks with information content of three bits or fewer, which require the participant to make a single choice from up to eight alternatives. The present research extends earlier studies in that a model is proposed that allows prediction of CRT for K multiple simultaneous responses to a stimulus array size N (where K = 1, 2, 3, etc.). In this model, the earlier formulation of Hick's law becomes the case where K = 1. The model was tested using 80 participants with eleven experimental conditions including tasks of up to 6.1 bits. A regression coefficient of 0.96 was obtained for the data set, thereby confirming the linearity of the model. These results corroborate Hick's assertion about the constancy of information acquisition rates even under conditions where complex decisions are required. These findings have considerable theoretical significance with implications in areas such as attentional resource allocation, pattern recognition, and neural networks.   Roberts, R. D., Prichard-Levy, A., & Beh, H. C. (1990). A generalized model of Hick's Law: Implications for the study of intelligence. Paper presented at The XVIIth Australian Experimental Psychology Conference, Australian National University, Canberra, Australia, July, 1990. Attempts to relate intelligence to choice reaction time (CRT) have generally been guided by the Hick paradigm. Using this paradigm, researchers report significant correlations between various measures of intelligence and choice response (provided stimulus information is in the range of three bits and CRT does not exceed 1000 msec). In the present study, 80 participants were given the Ravens Standard Progressive Matrices Test (RPM) and a modified CRT task, which extended task difficulty beyond six bits of information. CRTs beyond 1000 msec were obtained for conditions exceeding the previous limit on Hick's law, with these showing substantial correlations (about 0.60) with RPM performance. Correlations between CRT at various levels of information content revealed a simplex structure indicative of an orderly relationship between task difficulty and intelligence. The implications of these findings for the relationships between task complexity, processing speed, and intelligence is discussed.   1991   Published Papers Roberts, R. D., Beh, H. C., Spilsbury, G., & Stankov, L. (1991). Evidence for an attentional model of human intelligence using the competing task paradigm. Personality and Individual Differences, 12, 445-455. This study examined competing task performance within an information theory framework. In the first of two experiments, 72 participants performed a card-sorting task presented at four levels of task difficulty (0-, 1-, 2-, and 3-bits) under both single and competing conditions. In the second experiment, estimates of fluid (Gf) and crystallized (Gc) ability, as well as short-term acquisition and retrieval (SAR), were obtained from 68 participants who performed the same tasks as the participants in Experiment 1. The results of both experiments suggest that rate of processing remains invariant under both single and competing task conditions, such that the latter condition may be interpreted as introducing an additional bit of information. In Experiment 2, the introduction of the competing condition is shown to lead to higher correlation between processing parameters and Gf (but not Gc or SAR) marker tests.   Conference Papers Beh, H. C., Roberts, R. D., & Pearse, T. (1991). Processing speed and intelligence: A developmental perspective. Paper presented at The XVIIIth Annual Experimental Psychology Conference, Flinders University, Adelaide, South Australia, Australia, September, 1991. A study was conducted using 122 participants aged between 9 and 15 years to examine the application of Hick's law to children. The results indicate that: (a) Choice Reaction Time (CRT) is linearly related to information level up to a 2-bit task for all age groups, with the relationship relatively equivocal beyond this point. (b) Response time exhibits a monotonically decreasing function with age for each information level examined. (c) While the correlation between fluid intelligence (Gf) measures and CRT is significant, the correlation between CRT and crystallized intelligence (Gc) may largely be accounted for by taking into account chronological age.   1994   Published Papers Beh, H. C., Roberts, R. D., & Prichard-Levy, A. (1994). The relationship between intelligence and choice reaction time within the framework of an extended model of Hick's Law: A preliminary report. Personality and Individual Differences, 16, 6, 891-897. In this study, an extension to the classic Hick model is proposed and information levels above 3 bits are used to examine the nature of the relationship between choice reaction time (CRT) and intelligence. For this purpose, 80 participants completed the Standard Ravens Progressive Matrices Test (RPM) as well as a CRT task where information values varied from 0-6.1 bits. It was found that correlations between RPM scores and CRT measures were significant at all information levels, with median CRT measures being most highly correlated with intelligence.   Stankov, L., Roberts, R. D., & Spilsbury, G. (1994). Attention and speed of test-taking in intelligence and aging. Personality and Individual Differences, 17, 2, 273-284. This study provides a partial replication of Stankov's (1988, Psychology and Aging, 3, 1-16) finding that attentional variables can account for some of the age-related changes in intelligence test performance. Particularly important are processes involved in search (clerical-perceptual speed) tasks and paradigms requiring mental concentration. A further aim was to study the role of speed of test-taking parameters. Estimates of this variable are shown to give additional information to number-correct measures and to correlate highly amongst themselves, providing empirical support for a broader speediness factor than that suggested in the past.   Conference Papers/Published Abstracts Roberts, R. D., & Stankov, L. (1994). Speed of processing within the structure of human cognitive abilities. Paper presented at The Symposium on Australian Studies of Human Intelligence: XXIst Annual Australian Experimental Psychology Conference, University of Sydney, Sydney, Australia, April, 1994. (Published Abstract in Australian Journal of Psychology, 46, 26). This paper reports on analyses of data obtained as part of Roberts' (1995) Ph.D. dissertation. Two findings are emphasized: (a) Different cognitive abilities share different patterns and magnitude of correlation with various speed of information processing measures. (b) Mental speed measures have a more complex factorial structure than that generally suggested in the contemporary literature.   Maccallum, P., Beh, H. C., & Roberts, R. D. (1994). Sleep deprivation and performance: An information theory approach. Paper presented at The XXIst Annual Australian Experimental Psychology Conference, University of Sydney, Sydney, Australia, April, 1994. (Published Abstract in Australian Journal of Psychology, 46, 19). Results from sleep deprivation studies tend neither to be consistent nor easily generalized, especially when task complexity is considered. In an attempt to understand the findings in this area, the present study was designed within an information theory framework to examine the relationship between sleep deprivation and variation in task complexity. Three groups of 12 participants who had experienced normal, partial or no sleep on the night prior to testing performed a series of tasks that permitted the examination of complexity along two dimensions. The results indicated that both speed and rate of information processing were impaired following sleep deprivation and that the degree of impairment was related to the level of task complexity. The findings have been interpreted as supporting an information theory model of processing and indicate the relevance of such a model to the area of performance following sleep disturbance.   Roberts, R. D. (September, 1994). The Factor Structure of Mental Speed Measures. Department of Psychology Colloquium, University of Sydney, Sydney, NSW, Australia. also presented at Department of Psychology Colloquium: The University of Sydney, Sydney, Australia, NSW, September, 1994. Reports on a series of exploratory factor analyses of mental speed batteries, arguing that the structure of mental speed is more complex than other researchers have allowed. Problems delineating the structure of mental speed constructs are also discussed in the light of this research.   1995   PhD Dissertation R. D. Roberts (March, 1995). Speed of Processing within the Structure of Human Cognitive Abilities. Unpublished Ph.D. Thesis, Department of Psychology, University of Sydney, Sydney, Australia. (Supervisor: Lazar Stankov; Thesis Referee's: Professor J. B. Carroll, Professor Keith Widaman; Dr George Oliphant). Current research within the speed of processing paradigm has tended almost exclusively to examine the relationship between general intelligence (psychometric g) and a variety of chronometric (i.e., time-dependant) variables derived from elementary cognitive tasks (ECTs). This emphasis has ignored a compelling hypothesis that human cognitive abilities are arranged in a hierarchical structure involving three levels or strata -- each of which need be understood before claims can be made concerning the theoretical underpinnings of intellectual functioning (Carroll, 1993). Likewise, theories concerning the structure of human ability tend to assume that cognitive speed is unitary in nature, ignoring the possible complex structure of this variable. The present study addressed both of these shortcomings. 179 participants (110 female) performed a battery of eleven ECTs selected on the basis of information theory as well as a battery of twenty-five cognitive ability tests selected on the basis of the theory of fluid (Gf) and crystallized (Gc) intelligence. From cognitive ability tests measures of both level (i.e., number correct) and speed-of-test-taking were obtained. Using exploratory factor analytic techniques, previously identified level factors corresponding to those given by Gf/Gc theory (i.e., Gf, Gc, Short-term Acquisition and Retrieval, Broad Visualization, Broad Auditory Function, and Clerical-perceptual Speed) were defined, with evidence also indicating three speed-related factors hitherto undefined by psychometric tests. Detailed analyses of the microstructure of each ECT were conducted before correlating these with cognitive ability measures. This revealed substantial anomalies in a number of intraindividual parameters and shortcomings in the extant literature. Moreover, by and large the correlation of cognitive abilities with chronometric parameters indicated that fluid intelligence alone among level abilities is implicated with speed of processing - more specifically when task complexity was manipulated in the conditions constituting respective information theory measures. Regarding the possible factorial structure of cognitive speed, the results were unequivocal: there are a number of broad speed factors that may be derived from both chronometric and cognitive ability tasks. These were shown to be largely independent from level abilities and to collectively define a general cognitive speed factor. The implication of these various findings to the structure of human abilities is discussed. It would appear that the concept of mental speed is more complex than first proposed, and that like level abilities cognitive complexity may play a crucial role. With respect to attempts to account for individual differences in cognitive abilities by means of speed of processing measures, a number of theoretical explanations would not appear to be supported by the data. It is likely that the search for basic processes of intelligence (by means of this research program alone) is misguided.   Conference Papers/Published Abstracts Roberts, R. D., & Stankov, L. (1995). The place of mental speed within the structure of human abilities. Paper presented at The XXIInd Annual Australian Experimental Psychology Conference, University of Queensland, Brisbane, Australia, April, 1995. (Published Abstract in Australian Journal of Psychology, 47, 21). This paper reports on a series of further findings obtained from Roberts' (1995) Ph.D dissertation. Factor analyses of various data sets suggest that: (a) Mental speed measures form a number of lower-order factors that define five broad factors at the second-order and a single factor at the top of a hierarchy. (b) The highest-order speed factor would appear to have the same status as broad factors defined by level (i.e., scores derived from number correct) (e.g., fluid and crystallized intelligence constructs).   Roberts, R. D., Lane, P., Anne, D., Hinchcliffe, N., & Newman, K. (1995). Dynamic spatial ability within the structure of human abilities. Paper presented at The XXIInd Annual Australian Experimental Psychology Conference, University of Queensland, Brisbane, Australia, April, 1995. (Published Abstract in Australian Journal of Psychology, 47, 21). This study examined dynamic spatial ability (i.e., video-game-like performance) within the hierarchical framework of the theory of fluid and crystallized intelligence. While the experimental tasks chosen as indicative of dynamic spatial ability resembled those used by Jackson, Vernon, & Jackson (1993, Intelligence, 17, 451-460), a more extensive battery of psychometric and chronometric tests of cognitive abilities was employed than in that study. The results obtained were interpreted as indicating dynamic spatial performance constitutes a broad ability factor independent from those identified by existing psychometric tests.   Roberts, R. D., & Stankov, L. (1995). Mental speed within the structure of human cognitive abilities. Paper presented at The VIIth Meeting of the International Society for the Study of Individual Differences, Warsaw, Poland, July, 1995. This paper reports a Schmid-Leiman transformation of nine Movement Time measures, nine Reaction Time indices, and fifteen speed-of-test-taking variables obtained from a sample of 179 participants. On the basis of this, and other evidence reviewed herein, a three-stratum model of mental speed is proposed. This model has important implications for proponents who claim that mental speed is the ëbasic' process of intelligence.     1996   Published Papers Roberts, R. D., Pallier, G., & Stankov, L. (1996). The basic information processing (BIP) unit, mental speed and human cognitive abilities: Setting the BIP to RIP? Intelligence, 23, 133-155. Lehrl and Fischer (1990, European Journal of Personality, 4, 259-286) report findings derived from a series of tests that they claim measures a basic parameter of human information processing (BIP). Lehrl and Fischer also suggest that such indices share significant correlation with general intelligence. In this study these propositions were examined along with the expectation that BIP would share significant correlation with speed of information processing parameters. The results obtained cast doubts on the usefulness of the theoretical model presently postulated by Lehrl and Fischer. Rather than reflecting some properties of a limited capacity system, the BIP would appear nothing more than a marker test for a known primary mental ability -- Reading Speed.   Stankov, L., & Roberts, R. D. (1996). Mentalna brzina nije 'bazicni' proces inteligencije. Zbornik Zavoda za Pedagoska Istrazivanja, 28, 384-411. Theoretical and practical limitations of research attempting to link processing speed with intelligence are discussed. In particular, it is argued that biological models offered to account for this relationship are conceptually flawed. Instead, our research indicates that stimulus-response compatibility effects may mediate the correlation between processing speed and intelligence.   Roberts, R. D. (1996). Fitts' law, psychomotor performance, and intelligence. Paper presented at The 38th Annual Conference of the International Military Testing Association, San Antonio, Texas, USA, November, 1996. (Published in Proceedings of the 38th Annual Conference of the International Military Testing Association. San Antonio, TX: AFPC/ALHRM/AFOMS [p.347-373]). The hyperlink above will take you to the e-paper of the IMTA conference, which is hosted by The Institute for Job and Occupational Analysis (IJOA). Note that you will have to use your back button to return to this page.   Conference Papers/Published Abstracts Roberts, R. D. (1996). Intraindividual parameters of elementary cognitive tasks (ECTs): Some troublesome trends. Paper presented at The 31st Annual Australian Psychological Society Conference, Wentworth Hotel, Sydney, Australia, September, 1996. (Published Abstract in Australian Journal of Psychology, 48, 136-137). In this paper, I describe certain parameters of elementary cognitive tasks that are problematic. If you are interested in this topic you might like to follow this link to my e-paper on ECTs which discusses this issue in great detail.   Roberts, R. D. (1996). Towards a theory linking processing speed, cognition, and intelligence. Paper presented at Psychology Department Colloquium: Texas Technological College, Lubbock, Texas, USA, October, 1996. Reviews the literature examining linkage between processing speed and intelligence, and higher-order cognitive components (e.g., working memory) and human abilities (particularly fluid intelligence). It is proposed that stimulus-response compatibility effects mediate the correlation between processing speed and fluid (but not many other factors of) intelligence. A similar construct, cognitive complexity, would appear crucial to a proper understanding of relations between working memory and intelligence. Researchers should focus their energies on more systematic examination of compatibility and complexity manipulations in order to ameliorate conceptual contradictions currently prevalent in the individual differences literature.   1997   Published Papers Stankov, L., & Roberts, R. D. (1997). Mental speed is not the 'basic' process of intelligence. Personality and Individual Differences, 22, 1, 69-85. It is argued that the role played by mental speed in human intelligence research has been overemphasized. While it is accepted that mental speed is an important aspect of intelligence, determination of this as the basic process underlying individual differences is a consequence of flawed logic. This may be attributed to several questionable research practices and/or theoretical shortcomings. These include: (a) The adoption of a narrow neo-Spearmanian model of intelligence (rather than accepting a complex, hierarchy of cognitive abilities). (b) Selective interpretation of the available empirical evidence (wherein correlations between mental speed and intelligence measures are actually mediocre and certainly of no greater order of magnitude than many other elementary cognitive processes). (c) A failure to realize that the factorial composition of mental speed may be as complex as that for number correct (i.e., level) measures. (d) The acceptance of two main paradigms in the literature - Choice Reaction Time (CRT) and Inspection Time (IT) -- both of which contain a number of unresolved controversies. (e) A tendency to examine in post-hoc fashion, those parameters of CRT and IT tasks that show correlations with measures of intelligence. (f) The absence of a satisfactory explanatory model to account for the correlations between mental speed and intelligence.   Roberts, R. D. (1997). Fitts' law, movement time and intelligence. Personality and Individual Differences, 23, 2, 227-246. Recently, several published studies have reported an empirical relationship between Movement Time (MT -- i.e., the speed associated with sensori-motor control of movement) and intelligence. However, this finding is very much at odds with early research that suggested that there was no relationship between measures of these two constructs. One explanation for this anomaly is that intelligence has generally been imprecisely defined across disparate research programs, often with reference to a single test. Another explanation is that studies currently conducted involve poor operationalization of psychomotor processes, essentially confounding this aspect with other psychological mechanisms (e.g., Decision Time). In short, analyses of MT and intelligence have not been truly representative of these constructs, at least as conceptualized within more widely accepted models of these psychological processes. The present study examined the relationship between MT and intelligence by first selecting tasks in each domain that are representative of established psychological theories. One hundred and seventy-nine participants performed a psychomotor task conforming to Fitts' law (an information theory principle relating MT to task difficulty) and a battery of twenty-five psychometric tests. The latter measures were selected in order to define six broad cognitive ability factors under the framework of Gf/Gc theory. Microstructural properties of the psychomotor task were examined in as rigorous a fashion as possible. Evidence indicated adherence to simplex structure, group and intraindividual conformity to Fitts' law and a hitherto unreported linear relationship between variability and the pre-scaled function of target distance and width. However, with the notable exception of a well-defined broad speediness function (Gs), correlations between psychomotor parameters and psychometric measures were close to zero. These results are discussed in relation to cognitive and biological models of human cognitive abilities.   Roberts, R. D., Stankov, L., Pallier, G., & Dolph, B. (1997). Charting the cognitive sphere: Tactile and kinesthetic performance within the structure of intelligence. Intelligence, 25, 2, 111-148. In his extensive review of factor analytic studies conducted this century, Carroll (1993) laments that "information on tactile and kinesthetic sensitivity factors is meager" (p. 546). The present study sought to redress this imbalance by employing eight tactile-kinesthetic indices along with a battery of twenty-seven cognitive ability and mental speed measures. A sample of 195 participants was tested. Confirmatory factor-analysis of this data set indicated the existence of three first-order ‘level’ (i.e., accuracy) factors; two first-order ‘speed’ factors; and two first-order ‘mixture’ factors that reflected disparate features of short-term memory. A second-order confirmatory factor analysis of these constructs suggests that tactile-kinesthetic abilities share much in common with broad visualization and fluid intelligence, little in common with crystallized intelligence, and a series of differential relationships with ‘speed-related’ factors. A separate exploratory factor analytic solution (involving a reduced set of experimentally independent variables) supported these conclusions.   Roberts, R. D., & Goff, G. N. (1997). ASVAB: Little more than crystallized intelligence (Gc)? Paper presented at The 39th Annual Conference of the International Military Testing Association, Sydney, October, 1997. (Published in Proceedings of the 39th Annual Conference of the International Military Testing Association. San Antonio, TX: AFPC/ALHRM/AFOMS). An e-paper of this presentation is due to appear on the IMTA home page in the not too distant future. The above link takes you to that organization's WWW site.   Conference Papers/Published Abstracts Roberts, R. D. (1997). The factor structure of Reaction Time and its relationships to intelligence. Paper presented at The Second Spearman Conference, University of Plymouth, Plymouth, England, July, 1997. This paper presents data in which measures of processing speed exhibit a complex, hierarchical structure (akin to that found for human level abilities). Moreover, processing speed is differentially correlated to broad cognitive ability factors. The above link will take you to the powerpoint presentation that supports these claims.   Roberts, R. D. (1997). Processing speed, stimulus-response compatibility and intelligence. A symposium paper presented at The VIIIth Biennial Meeting of the International Society for the Study of Individual Differences, The University of Aarhus, Aarhus, Denmark, July, 1997. The above link will take you to the powerpoint presentation that I gave at this conference (which was notable in being the last public appearance of Professor Hans Eysenck). Note that this paper was actually part of a symposium (entitled "New Directions in Ability Research") that Patrick Kyllonen and I organized for this conference. You can click on this link to see abstracts of the entire series of papers presented at this symposium.   Roberts, R. D., Kyllonen, P. C., Zukor, K., & Rea, M. (1997). Circadian rhythms, personality and intelligence: New directions. Paper presented at The VIIIth Biennial Meeting of the International Society for the Study of Individual Differences, The University of Aarhus, Aarhus, Denmark, July, 1997. Circadian rhythms are daily fluctuations in psychological and behavioral functions generated by internal pacemakers. Both at the practical (e.g., gauging shift-work tolerance) and conceptual level (e.g., modeling human performance) the significance of individual differences in various phenomena associated with these circadian rhythms (e.g., the peak and amplitude of specific psychological functions over the course of a day) should not be ignored. In this paper a review of past studies involving circadian rhythms and their relationship to both personality and intelligence is conducted. A major weakness of these studies is that they appear largely atheroetical. Specific limitations include: (a) Failure to utilize advances in psychological theory to bear on the issues under investigation (e.g., reporting results in terms of Eysenck’s rather than the ‘Big Five’ factor model of personality). (b) Questionable research practices (e.g. the use of small sample sizes). (c) Failure to integrate relatively sophisticated biological and neurochemical models. (d) The use (or perhaps, better, abuse) of largely inappropriate analytical procedures. (e) Assorted (other) methodological deficiencies (e.g., the derivation of a single dimension of morning-eveningness from tests that are clearly multifaceted). In an attempt to overcome these shortcomings, a large sample (N = 300) was administered a selection of circadian measures (e.g., Horne and Ostenberg’s Morningness-Eveningness Questionnaire), along with tests of working memory and processing speed, a mood survey (the Watson-Clark-Tellegen Positive Affect Negative Affect Scale), and a personality inventory measuring the 'Big Five' factors (Christal’s Trait-Self Description Inventory). Correlation analyses were conducted to explore the links between the circadian measures, cognitive, personality, and mood data. Based on these analyses, a tentative framework for linking these variables is reported.   Roberts, R. D. (1997). Individual differences in performance as a function of the time-of-day. Paper presented at 'The Brown Bag' Colloquium: Armstrong Laboratory, Brooks AFB, TX, August, 1997. This paper reviews the literature on time-of-day and in particular, the effects of circadian rhythms on human performance. It is noted that there are two different approaches to this issue: the correlational and the experimental, and that unlike abilities research, there has been little attempt to establish a rapproachment between these two research domains.   Roberts, R. D. (1997). Individual differences in diurnal preference. Paper presented at The US AFSOR Chronobiology and Neural Adaptation Conference, Colorado Springs, Colorado, USA, September, 1997. This paper is an extension of one presented at the ISSID Conference in Aarhus. While that presentation involved preliminary data, this includes a data set of 420 participants and a detailed critique of extant measures of diurnal preference/circadian type. The above link will take you to the powerpoint presentation that I gave at this conference (which was was attended by several of the most pre-eminent scientists working in the area of chronobiology).   Roberts, R. D., & Pallier, G. (1997). Sensory processes within the structure of human cognitive abilities. Paper presented at The Future of Learning and Individual Differences Research Conference: Processes, Traits, and Content, The University of Minnesota, Minnesota, MN, USA, October, 1997. It is argued that the domain circumscribing human cognitive abilities is not static. This proposition would appear self-evident as new abilities surface in response to emerging technologies. However, it must also be acknowledged that there are many sensory processes that are repeatedly employed in an individual s day to day strivings that have been consistently bypassed without any attempt at systematic exploration. For example, although the cognitive literature is replete with studies examining the processes underlying audition and musical performance, investigation of individual differences in these abilities has been sparse. A possible explanation for this state of affairs is that in needing to obtain large sample sizes individual differences researchers have been forced to invest most of their resources into the study of visual processes. Notably, both paper and pencil and computer technologies are ideally suited to this end, rather than to the investigation of other sensory mechanisms. In this paper, we argue that any attempt to posit a taxonomy of human cognitive abilities will be incomplete without consideration of individual differences in each of the so-called lower-order sensory processes. Indeed, it is entirely possible that these sensory processes may be basic to higher-order factors of intelligence (Stankov & Roberts, 1997). In addition, we suggest that because human factors research has begun to explore the impact of multiple channels on ergonomic issues, obtaining an understanding of sensory abilities would seem pivotal to the survival of applied portions of our field. To this end, we review (isolated) multivariate studies examining auditory, olfactory, and tactile-kinesthetic abilities. Recent studies of these processes are suggestive of new theories that are ostensibly anti-reductionist in their sentiment. As computer technologies incorporating advances in software and hardware features (and the ‘virtual world’ that they access) emerge, it is likely more attention will be directed towards consideration of sensory abilities. However, the science of individual differences should not be driven purely by one technology lest this leads to a degenerative research program. To illustrate this point, we focus on contemporary experimental studies of tactile perception and olfaction that employ novel methodologies, pointing to several interesting findings that have resulted. We conclude that although studies examining sensory processes may prove time consuming to conduct, the ‘cost’ to the individual researcher is far outweighed by the overall contribution to individual differences psychology.   Kyllonen, P. C., Roberts, R. D., & Irvine, S. (1997). Predicting the learning of simple electronic gates. Paper presented at The Future of Learning and Individual Differences Research Conference: Processes, Traits, and Content, The University of Minnesota, Minnesota, MN, USA, October, 1997. A total of 303 participants were administered a computer-based version of the ARCOM Battery and eight Logic Gates learning trials. Test outcome variables were scores adjusted for guessing and the average latency per item in milliseconds. Logic Gates Trials were scored for percentage correct and average time per item. In addition, the ASVAB scores for each participant were obtained from records. Findings confirm those of a previous study carried out by Christal (1990), where experimental tests of accuracy and speed of mental processing were more effective than ASVAB tests in predicting logic gates learning. They also lend weight to the contention by Kyllonen and Christal (1990) that general intelligence and working memory are closely related.   Roberts, R. D. (1997). Chronopsychology: New investigations. Paper presented at Department of Psychology Colloquium: Macquarie University, Sydney, Australia, NSW, October, 1997. Roberts, R. D. (1997). Research into circadian types: Concepts, prospects, and limitations. Paper presented at Department of Psychology Colloquium: University of Sydney, Sydney, NSW, Australia, October, 1997. In these two related presentations, I review extant measures of circadian type to conclude that virtually all are plagued by psychometric limitations. To redress this shortcoming, I have devised a new instrument for the assessment of circadian type -- the Lark-Owl Chronotype Indicator (LOCI). Preliminary data is reported that shows this measure to be both highly reliable and valid.     1998   Published Papers Davies, M., Stankov, L., & Roberts, R. D. (1998). Emotional Intelligence: In search of an elusive construct. The Journal of Personality and Social Psychology 75, 4, 989-1015. Current theorizing views the processing of affective information as a type of ‘mental’ ability, asserting that ‘emotional’ intelligence should be included within the traditional cognitive abilities framework. This paper reports three studies (total N = 530) investigating the relationship between measures of emotional intelligence, traditional human cognitive abilities, and personality. The studies suggest that the status of the emotional intelligence construct is limited by measurement properties of its tests. Measures based on consensual scoring exhibited low reliability. Self-report measures had salient loadings on well-established personality factors (i.e., Neuroticism, Extraversion, Psychoticism, Agreeableness, and Openness) indicating a lack of divergent validity. These data sets provide controvertible evidence for the existence of a separate Emotion Perception factor (perhaps representing the ability to monitor another individual’s emotions) that, in turn, future studies might explore more fully. However, this factor appears much narrower than that postulated within current models of emotional intelligence.   Conference Papers/Published Abstracts Roberts, R. D. (1998). Making sense of (the) sense abilities. Paper presented at Department of Psychology Colloquium: Macquarie University, Sydney, NSW, Australia, March, 1998. In this presentation, I reinterpret findings from studies obtained in mental speed research, to indicate the primacy of sensory processing to fluid intelligence constructs (in particular).   Stankov, L., Davies, M., & Roberts, R. D. (1998). Emotional Intelligence: Separating the facts from the (best-selling) fiction. Paper presented at The XXVth Annual Australian Experimental Psychology Conference, University of Tasmania, Tasmania, Australia, April, 1998. (Published as an abstract in Australian Journal of Psychology, 50, 63.) Emotional intelligence has been defined as "the ability to monitor one's own and others' emotions, to discriminate among them, and to use the information to guide one's thinking and actions" (Salovey & Mayer, 1990, p. 189). As such, this construct encompasses a set of conceptually related psychological components involving the processing of affective information. These processes include (a) the verbal and non-verbal appraisal and expression of emotion in the self and others; (b) the regulation of emotion in the self and others, and (c) the utilization of emotion to facilitate thought. In this paper, however, we present data from several studies that question whether emotional intelligence (a) can be conceptualized as an ability and (b) is independent from known personality dimensions (particularly Neuroticism, Agreeableness, and Extraversion).   Roberts, R. D., Stankov, L., & Seizova, T. (1998). Individual differences in tactile and kinesthetic perception: Review and integration. Paper presented at 'The Brown Bag' Colloquium: Air Force Research Laboratory, Brooks AFB, TX, June, 1998. This presentation, which represents data collected from various studies examining tactile and kinesthetic processes, was the last one I gave at Brooks AFB while working for the National Academy of Sciences as a National Research Council Fellow. The paper may be viewed as a powerpoint presentation by following the above link.   1999 Published Papers/Book Chapters Roberts, R. D., Pallier, G., & Goff, G. N. (1999). Sensory processes within the structure of human cognitive abilities. In P. L. Ackerman, P. C. Kyllonen, & R. D. Roberts (Eds.), Learning and Individual Differences Determinants: Processes, Traits, and Content. Washington DC: American Psychological Association. In this book chapter, we discuss various findings in the literature that indicate sensory processes (e.g., tactile-kinesthetic perception, olfaction, and so forth) have been neglected for too long by differential psychologists. Data is presented that indicates mental speed constructs are best interpreted in light of sensory coding, and that these mechanisms provide a plausible (alternative) hypothesis by which to understand correlations with cognitive ability measures. A review of research conducted on individual differences in tactile-kinesthetic perception, olfaction, and audition is also undertaken. It is concluded that, if it is to lead to improved scientific understanding, a comprehensive taxonomic model of human capabilities must incorporate sensory processes.   Ackerman, P. L., Kyllonen, P. C., & Roberts, R. D. (1999). (Eds.) Learning and Individual Differences Determinants: Processes, Traits, and Content. Washington DC: American Psychological Association. You can follow the hyperlink to the APA's WWW site and find out many of the details surrounding this book that I co-edited with Professor Ackerman and Dr Kyllonen.   Conference Papers/Published Abstracts Roberts, R. D., Stankov, L., & Pallier, G. (1999). The Processing Speed-Accuracy Test (PAST) battery: Factor structure and behavioral correlates. XXVIth Annual Experimental Psychology Conference, Macquarie University, Sydney, New South Wales, Australia, April, 1999. A paper-and-pencil battery of 25 elementary cognitive tasks (ECTs) known as the Processing Speed-Accuracy Tests (PAST) was developed and then administered to 349 participants. Cognitive constructs assessed by these tasks include choice reaction time, attention switching, movement time, identification time, odd-man-out performance, and stimulus-response compatibility. Participants also completed measures of fluid and crystallized intelligence, technical knowledge, and short-term memory. Analyses indicate the ECTs have a complex, hierarchical structure. One lower-order factor (Attention Switching) has particularly high correlation with measures of fluid intelligence (i.e., r in excess of 0.5). Overall, differential magnitudes of correlation with identified ability constructs across each speed factor reinforces the view that the factor structure of speed is as elaborate as that found for accuracy based (i.e., level) measures.   Kleitman, S., Stankov, L., & Roberts, R. D. (1999). Cognitive strategies, metacognitive beliefs, and overconfidence: An individual differences perspective XXVIth Annual Experimental Psychology Conference, Macquarie University, Sydney, New South Wales, Australia, April, 1999. In this paper, we discuss certain implications from differential psychology, that might be applied to the study of metacognitive processes (including strategy-choice) and confidence ratings data.   Roberts, R. D. (1999). The Armed Services Vocational Aptitude Battery (ASVAB), The Bell Curve, and Gf/Gc Theory. IXth Biennial Meeting of the International Society for the Study of Individual Differences, Coast Plaza Hotel at Stanley Park, Vancouver, British Columbia, Canada, July, 1999. The ASVAB is one of the most widely used psychological tests in the world, influencing the career decisions of nearly 2 million young Americans per annum. It is also the principle psychological instrument upon which the conclusions of The Bell Curve rest. In this paper, I examine the factorial composition of the ASVAB in light of the theory of fluid and crystallized intelligence. Results from two studies are reported that suggest the ASVAB may adequately assess a factor related to acculturated learning (crystallized intelligence), but that this is insufficient to support any of the frequent claims made surrounding this test and psychometric g. In concluding, I question certain inferences drawn in The Bell Curve and note that the ASVAB should be revised to incorporate assessment of fluid intelligence and learning and memory constructs. Note that this paper was actually part of a symposium (entitled "New Directions for Research on Cognitive Development: Modifications of Gf/Gc") that Lazar Stankov and I organized for this conference. Among the presenters were Professor John Horn (my academic grandfather), Dr Richard Woodcock, and Professor Jack McArdle). You can click on this link to see abstracts of the entire series of papers presented at this symposium.   Roberts, R. D. (1999). Construction and validation of the Lark-Owl Chronotype Indicator (LOCI). Early Career Award Presentation to the IXth Biennial Meeting of the International Society for the Study of Individual Differences, Coast Plaza Hotel at Stanley Park, Vancouver, British Columbia, Canada, July, 1999. The term 'circadian' denotes the near 24 hour physiologic rhythm that has been observed under free-running conditions, at every system level in nearly all living things, under near constant environmental conditions. Within individual differences approaches to this phenomenon, there is a stated assumption that there exists definite types corresponding to diurnal preference. However, attempts to measure circadian type (or chronotype) have met with mixed results. The Lark-Owl Chronotype Indicator (LOCI) was developed to redress this shortcoming. LOCI is a brief self-report measure of circadian type yielding three sub-scale scores: Morningness, Eveningness, and Sleep Propensity. It has two parallel forms: LOCI (Alpha) and LOCI (Beta). Three studies (N = 1132) are reported that suggest the three sub-scales composing the LOCI have excellent psychometric properties. A fourth study (N = 500) demonstrates the validity of the LOCI. Correlations between peer-report and self-report LOCI scores are particularly high for all scales (average r = 0.51). The presentation concludes with a discussion of the theoretical implications of separating Morningness and Eveningness dimensions.   Kleitman, S., Stankov, L., & Roberts, R. D. (1999). Cognitive strategies and overconfidence. IXth Biennial Meeting of the International Society for the Study of Individual Differences, Coast Plaza Hotel at Stanley Park, Vancouver, British Columbia, Canada, July, 1999. People tend to exhibit overconfidence in the course of assessing their own performance in general knowledge tasks. This study examines the effects of cognitive strategies on calibration (the correspondence between people's beliefs about the accuracy of their performance and their actual performance). A new General Knowledge Test was designed to allow the assessment of three strategies: Reasoning, Guessing, and Knowing the answer to a test item. In addition, we used the Self-Perception Profile for College Students (Neemann & Harter, 1986), and a new Cognitive Abilities Profile Measure to assess people's beliefs about their thinking strategies. The General Knowledge Test showed no overconfidence. Regression analyses revealed that the type of strategy people report as being used to answer a question is the most important predictor of the general level of confidence. However, different self-perception and ability profiles make further contribution to the prediction. The three strategies of Reasoning, Guessing, and Knowing produced different calibration curves, with Knowing showing strong underconfidence, and Guessing and Reasoning showing reasonably high calibration.   Stankov, L., & Roberts, R. D. (1999). Hierarchical Models of Human Abilities and Basic and Elementary Cognitive Processes. Special Symposium on Intelligence Assessment, The Fifth European Conference on Psychological Assessment, Patras, Greece, August, 25-29,1999. In this paper, we argue that within the domain of psychology it is difficult to distinguish between causal variables and their effects, especially in correlational designs. Constructs from the domains of biology may be used in causal explanations of psychological observations. We examine the consequences of including sensory and other lower-level processes in studies of intelligence. The inclusion of measures from the whole domain of psychology (i.e., including sensory acuity measures) is likely to weaken the role of the general factor. Multivariate studies based on a large number of variables are the most useful way towards providing an understanding of structural relationships in psychology.   Roberts, R. D., Stankov, L., & Pallier, G. (1999). Processing Accuracy and Speed Test (PAST) Battery: Underlying theory, description, and validation. Special Symposium on Intelligence Assessment, The Fifth European Conference on Psychological Assessment, Patras, Greece, August, 25-29,1999. This paper may be viewed as a powerpoint presentation by following the above link.   In press Roberts, R. D.,& Kyllonen, P. C. (1999). Morningness-eveningness and intelligence: Early to bed, early to rise will likely make you anything but wise. Personality and Individual Differences. Research examining various psychological correlates of circadian type (also known as diurnal preference) has been, over the years, quite expansive. A notable omission within this research program would appear a systematic exploration of the relation between intelligence and Morningness-Eveningness. The present study redressed this imbalance. Four-hundred-and-twenty (420) participants performed two self-report inventories of circadian type, as well as measures of intelligence from two well-known psychometric batteries: CAM-IV and the ASVAB. The results indicate that, contrary to conventional folk wisdom, evening-types are more likely to have higher intelligence scores. This result is discussed in relation to current theorizing about the nature of human cognitive abilities.   Stankov, L., Seizova, T., & Roberts, R. D. (1999). Tactile and kinesthetic performance within the taxonomy of human cognitive abilities. Intelligence. The vast majority of research in psychology has been preoccupied with understanding visual and auditory processes. Clearly, other perceptual mechanisms generate meaningful individual differences, which might be related to intelligent functioning. The present study extends the results of a recent multivariate investigation examining critical features of tactile perception and kinesthesia. Participants (N = 116) were administered eight traditional psychometric instruments and fourteen measures of tactile and kinesthetic perceptual processes. The results are consistent with earlier findings in demonstrating that visual-spatial processes are difficult to disentangle from complex measures of tactile and kinesthetic processing. However, structural equation modeling provided evidence for independent kinesthetic and tactile factors that were (differentially) correlated with fluid intelligence. The first factor -- kinesthetic sensitivity -- represents an ability to determine (or remember) the position of the arm, or the trajectory of arm movements, without using vision. The second factor -- tactile sensitivity -- exemplifies an ability to discriminate and infer the form of fine stimuli applied to the skin. These tactile and kinesthetic processes appear narrower than other perceptual constructs such that they are encapsulated by first-order mental abilities (rather than broad intellective factors).   Roberts, R. D., & Stankov, L. (1999). Individual differences in speed of mental processing and human cognitive abilities: Towards a taxonomic model. Learning and Individual Differences. Extensive research focuses upon the relation between general intelligence and measures derived from elementary cognitive tasks (ECTs). This emphasis has ignored data indicating that cognitive abilities are best described by three levels (or strata). Similarly, while claims abound that mental speed is a unitary construct, it is more likely to have a complex structure. To address shortcomings evident in the literature, a multivariate investigation (N = 179) was conducted. Factor analysis of 25 psychometric indices gave seven factors postulated under the theory of fluid (Gf) and crystallized (Gc) intelligence. Correlations between cognitive abilities and parameters derived from 11 ECTs indicated that Gf (alone) was related to processing speed. This relation is dependent upon experimental manipulations of task complexity. Results also indicated several hitherto little understood broad second-order factors derived from speed measures. These constructs are independent from abilities defined by accuracy scores and collectively define a general cognitive speed factor. It would appear that mental speed is more intricate than proposed, and that cognitive complexity (reflected in stimulus-response compatibility effects) plays a crucial role. In addition, explanatory models linking intelligence to processing speed seem to be untenable. It is likely that the search for a basic process of intelligence by means of mental speed frameworks (alone) is misguided.   Pallier, G., Roberts, R. D., & Stankov, L. (1999). Biological vs. Psychometric Intelligence: Halstead's (1947) distinction re-visited. Archives of Clinical Neuropsychology. This paper reports an investigation into the empirical status of a little understood cognitive factor -- tactile-kinesthetic ability. To this end, a variety of haptic tasks, including three sub-tests of the Halstead-Reitan Neuropsychological Test Battery (HRNTB), were administered to 108 participants, along with established markers commonly employed in contemporary psychometric investigations. The results suggest that sub-tests of the HRNTB measure cognitive abilities conceptually equivalent to fluid intelligence. Since these tests were part of Halstead’s (1947) attempt to operationalize the concept of ‘biological intelligence,’ the results reported allow evaluation of this concept in relation to current models of human intelligence. Previous studies investigating the nature of abilities assessed by the HRNTB have reached contradictory conclusions. Present findings clarify the source of these anomalies.   Submitted Roberts, R. D., & Pallier, G. (1999). Individual differences in performance on elementary cognitive tasks (ECTs): Lawful vs. problematic parameters. British Journal of Psychology. In studies conducted within the cognitive correlates approach to intelligence it is common practice to derive a number of intraindividual parameters beyond typical (i.e., ‘average’) performance. These measures include, for example, the slope and intercept of Decision Time and measures of intraindividual variability. Of interest, each parameter is thought to reflect an important information process of the human cognitive system. In turn, by correlating these measures with established markers of intelligence, theoretical models for the latter, arguably more poorly understood, construct have been postulated. However, it is not entirely clear that these phenomena are as robust within the individual as has been proposed. A study involving 179 participants (who performed ten Elementary Cognitive Tasks [ECTs]) was conducted in order to test the efficacy of respective intraindividual parameters. While average performance on most of these ECTs was found to be lawful, it was also discovered that up to 40% of participants failed to provide acceptable indices of intraindividual model fit in a subset of the ECTs that employed between five and eight data points. Similarly, intraindividual variability measures were shown not to be as valid as has been suggested in the literature. In particular, the study failed to find one simplex pattern across several of the ECTs in which this parameter was obtained. The implications of these findings to a variety of cognitive and biological models of intelligence are discussed.   Roberts, R. D., Goff, G. N., Anjoul, F., Pallier, G., Kyllonen, P. C., & Stankov, L. (1999). The Armed Services Vocational Aptitude Battery: Not much more than acculturated learning!? Journal of Applied Psychology. Carroll’s (1993) reanalysis of the main data sets collected within the psychometric discipline suggests that human intelligence exists on three levels (or strata). The ensuing model has important implications for psychological and educational assessment, and in particular test development and interpretation. In this paper, we examine the factorial composition of the ASVAB in light of the three-stratum model. Results from two studies are reported that suggest the ASVAB may adequately assess a factor related to acculturated learning (crystallized intelligence), but that this is insufficient to support any of the frequent claims made surrounding this test and psychometric g. In concluding, we note that the ASVAB should be revised to incorporate assessment of additional factors mentioned under Stratum II of Carroll’s model, particularly fluid intelligence and learning and memory constructs.   Pallier, G., Danthiir, V., Kleitman, S., Knezevic, G., Stankov, L., & Roberts, R. D. (1999). The role of question format and individual differences in the realism of confidence judgements. Acta Psychologica. Self-assessment of accuracy in the cognitive domain typically leads to overconfidence. Studies examining this phenomenon have tended to disregard individual differences as a source of overconfidence. The present study used both open-ended and multiple-choice formats of tests (derived from the theory of fluid and crystallized intelligence) to examine the self-assessment paradigm. A larger than usual number of participants (n = 520) and test instruments was examined. The results indicate that meaningful individual differences may be a relevant source of overconfidence and that a trait (or ability) mediates this effect. The causes of miscalibration are argued to be more complex than previously envisaged. The placement of a 'confidence factor' within the continuum of human cognitive abilities is discussed.   Beh, H. C., Pearse, T., & Roberts, R. D. (1999). Competing tasks, Hick's law, and intelligence: A developmental perspective. Personality and Individual Differences. A study was conducted using 122 children aged between 9 and 15 years to examine the application of Hick's law to children. The results indicated that choice reaction time (CRT) was linearly related to information level in bits for up to 2-bit tasks for all age groups and that the relationship may extend beyond this information level. It was also found that response time showed a monotonically decreasing function with age for each information level studied and that both movement time and decision time displayed this function. Earlier reports of significant correlation between measures of fluid intelligence and CRT in children were confirmed and, in addition, evidence was found showing that the correlation between CRT and crystallized intelligence could be largely accounted for by taking account of chronological age.   E-papers Roberts, R. D. (1999). A description and empirical evaluation of ten elementary cognitive tasks (ECTs) subscribing to information theoretic principles. This is an extensive e-paper that I have written to accompany various manuscripts that are currently in press or under review.   Roberts, R. D., & Irvine, S. (1998). Construction and Validation of the Lark-Owl (Chronotype) Indicator (LOCI): Status Report August, 1999. This is a status report on the development and validation of a new measure of circadian type -- the Lark-Owl Chronotype Indicator (LOCI).   Book Contract Roberts, R. D., & Stankov, L. (1999-early, 2000). Mental Speed within the Structure of Human Cognitive Abilities. Cambridge, UK: Cambridge University Press. Although it has changed somewhat (as Lazar Stankov and I continue to write, do research, and new findings are reported in the field) you can find the original abstract of this book (that we are writing for Cambridge University Press) in the passages below. After an evaluation of available evidence, the book proposes a new taxonomy of mental speed. This leads to a series of arguments that throw doubt on the popular belief that mental speed is the basic process of human intelligence. Overall, the book suggests positive solutions to notable gaps in the understanding of widely held psychological constructs, particularly the nature and role of mental speed in human cognitive functioning. Specifically, by examining scientific research within this context, we show that it is only the relationship between general intelligence (psychometric g) and a variety of chronometric (i.e., timed) variables obtained from elementary cognitive tasks that has been investigated to date. This emphasis has ignored a substantial body of evidence that indicates human cognitive abilities are best described by a hierarchical structure involving three levels (or strata) - each of which need to be understood before positing an explanatory model of intellectual functioning (Carroll, 1993). In a similar vein, theories concerning the structure of human cognitive abilities continue to assume that mental speed is unitary in nature, ignoring the likely complex structure of this psychological variable. This book seeks to address each of these shortcomings, arguing that intelligence has a complex structure which cannot be captured by simplistic explanations. The construct of mental speed is examined by evaluating the large number of studies employing this construct in one way or another. Detailed attention is given to various speed-related concepts, since not only a large number of disparate paradigms encompass this construct, but there are also a large number of parameters that may be obtained within any single experimental framework. With respect to the later, the approach adopted by the authors is highly critical since the available evidence indicates that several parameters have questionable conceptual status. However, after scrutinising mental speed measures from a variety of statistical and theoretical perspectives, some parameters are shown to be scientifically valid. This leads to an examination of concepts that arise from these paradigms and their relationship to a variety of psychological phenomena. Of critical interest, a number of mental speed constructs are shown to share differential relationships with the disparate cognitive ability factors that have been identified by contemporary researchers working within the area of intelligence. For example, it is demonstrated that fluid intelligence (more so than any other traditional human cognitive ability) is implicated with speed of information processing - particularly when task complexity is manipulated in the conditions constituting respective mental speed measures. The notion of a structure underlying mental speed is addressed in the book. The authors reach the theoretically important conclusion that there are a number of broad speed of performance factors that may be derived from both chronometric and cognitive ability tasks. These are shown to be factorially independent from many traditional intellectual abilities and to collectively define a general cognitive speed factor. The book continues by examining theoretical implications for a scientific conceptualisation of human cognitive abilities. The construct of mental speed is shown to be more intricate than previously proposed such that, as for traditional human abilities, cognitive complexity would appear to play a crucial role in the differentiation of this psychological factor. With respect to attempts to account for individual differences in cognitive abilities by means of mental speed measures, a number of theoretical explanations would appear not to be supported by the empirical data. It is likely that the search for a basic process of intelligence by means of the frameworks so far employed in the literature are misguided. Similarly flawed are practical programs (e.g., personnel selection) and social policy decisions that rely too heavily upon a reductionist approach. Consequently, alternative models (and their implications to these disparate areas of psychological inquiry) are examined. In particular, a model emphasising the integration of S-R compatibility effects, attention, and hitherto neglected psychobiological factors is described. It is concluded that the model of mental speed proposed in the book provides a progressive paradigm (in the Kuhnian sense [see Kuhn, 1970]) for the science of individual differences.   2000- Below you will find a number of manuscripts or projects that I am currently working on, which I hope to finish in the year 2000: Heggestead, E., & Roberts, R. D. (1999-2000). Tellegen's Multidimensional Personality Questionnaire: Cross-links to motivation, social competence, and emotional intelligence in a large military sample. Irvine, S., & Roberts, R. D. (1999-2000). Lifestyle preference and the morningness-eveningness dimension. Kyllonen, P. C., & Roberts, R. D. (1999-2000). Emotional intelligence and the Big Five Factor Model. Matthews, G., Zeidner, M, & Roberts, R. D. (1999-2001). Emotional Intelligence: Science and Myth. Myors, B., Roberts, R. D., & Stankov, L. (1999-2000). A generalized parametric model for stimulus-response compatibility effects in reaction time. Pallier, G., Roberts, R. D., & Stankov, L. (1999). Exploring the psychological correlates of self-confidence. Roberts, R. D. (1999-2000). Individual differences in sleep quality and propensity: A multivariate investigation. Roberts, R. D. (1999-2000). A conjoint measurement analysis of divided attention. Roberts, R. D., & Buffier, F. (1999-2000). Social intelligence and its relation to measures of fluid and crystallized intelligence. Roberts, R. D., Irvine, S., & Kyllonen, P. C., (1999-2000). Circadian type, mood-state, and personality: A review and empirical investigation. Roberts, R. D., & Myors, B. (1999). Dynamic spatial performance: Personality, circadian, and cognitive ability correlates. Roberts, R. D., & Shute, V. (1999). The Belief in Parapsychological Phenomenon Inventory: Factor structure and construct validation. Stankov, L., Pallier, G., & Roberts, R. D. (1999-2000). Cognitive and personality correlates of tactile-kinesthetic performance.   Test Development Below I list various psychometric instruments that I have developed. Over time, on the Individual Differences e-paper page, I will present status reports on each of these instruments. Note that I list the status of all test instruments that I have developed as unpublished. This is not a strictly accurate reflection of their status since (a) LOCI is being commercially piloted by INPSYCH in Europe and (b) tasks contained within PAST and CABS have been catalogued under the Learning and Aptitude Measurement Program (USAFRL). Roberts, R. D., & Irvine, S. (1999-2001). The Lark-Owl (Chronotype) Indicator (LOCI). Unpublished Inventories (Alpha- and Beta- Forms), Scoring Keys, Test Manual, and Validation Data. The Status Report of validity studies conducted on this instrument (prior to August 1999) is available at the above link.   Roberts, R. D., Pallier, G., & Stankov, L. (1999-2000). The Processing Speed-Accuracy Test (PAST) Battery. Unpublished Battery, Scoring Keys, Test Manual, and Validation Data. For sample items from the PAST-BAT go to the powerpoint presentation provided in the link above.   Roberts, R. D., & Burns, N. (1999-2000). The Computerized Assessment of Broad Speediness (CABS) Battery. Unpublished Battery and Validation Data.   Roberts, R. D., Krause, H., & Suk-Lee, L. (1999-2001). Australian Time Organization and Management Scales. Unpublished Inventory.   Schneider, R., & Roberts, R. D. (1999-2000). Construct and empirical validation of the Social Competence Inventory. This study was designed to assess the psychometric properties of a Social Competence Inventory (SCI) designed by the Chief Investigator (Dr Rob Schneider). In total, approximately 800 participants have now completed the SCI, along with measures of personality, social and emotional intelligence, and a variety of cognitive abilities subscribing to the theory of fluid and crystallized intelligence. Presently data are being scored and collated. To obtain some feel for the constructs assessed by the SCI, its twenty-five scales are listed below. Social Appropriateness (15 items): "You are courteous even to people you don't like." Social Knowledge (12 items): "You have a good sense of the difference between what’s socially acceptable and what isn’t. Social Memory (17 items): "You almost never forget a face." Social Insight (14 items): "You understand the motivations of others." Social Planning Ability (11 items): "You have sometimes gotten people to do what you want by making them think it was their idea." Warmth (16 items): "You don't go out of your way to help others." Sociability (14 items): "You make friends easily." Social Influence (15 items): "You defend ideas that you believe in vigorously." Social Calmness (15 items): "You are at ease around most people." Social Connectedness (15 items): "You find it hard to get close to people. Non-Aggressiveness (13 items): "When people tried to draw you into fights, you usually walked away." Social Openness (14 items): "You try to understand others' viewpoint." Social Self-Confidence (10 items): "When you meet new people, you know they will like you." Team Orientation (15 items): "You would rather work as part of a team than on your own." Charisma (16 items): "People are drawn to you." Impression Management (14 items): "You are careful to behave in ways that protect or improve your reputation." Emotion Control (13 items): "It takes an awful lot for you to lose your composure." Conversation Skills (17 items): "You have been told that you're witty." Listening Skills (13 items): "You have a tendency to interrupt others during conversations." Oral Communication Skills (11 items): "You tend to talk too fast." Nonverbal Expressiveness (13 items): "You often gesture to emphasize an important point." Coaching Skills (19 items): "You enjoy teaching people to do things." Conflict Management Skills (18 items): "You have often played the role of peacemaker." Negotiating Skills (14 items): "You are good at bluffing when negotiating with people." Overall Social Effectiveness (4 items): "You consider yourself a socially competent person."
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