A rasch model for partial credit scoring

A unidimensional latent trait model for responses scored in two or more ordered categories is developed. This “Partial Credit” model is a member of the family of latent trait models which share the property of parameter separability and so permit “specifically objective” comparisons of persons and items. The model can be viewed as an extension of Andrich's Rating Scale model to situations in which ordered response alternatives are free to vary in number and structure from item to item. The difference between the parameters in this model and the “category boundaries” in Samejima's Graded Response model is demonstrated. An unconditional maximum likelihood procedure for estimating the model parameters is developed. Preparation of this paper was supported by grants from the Spencer Foundation and the National Institute for Justice. I would like to thank Professor Benjamin D. Wright of the University of Chicago for his very kind help with the various drafts of this paper.     

Random effects and extended generalized partial credit models

In this paper it is shown that under the random effects generalized partial credit model for the measurement of a single latent variable by a set of polytomously scored items, the joint marginal probability distribution of the item scores has a closed-form expression in terms of item category location parameters, parameters that characterize the distribution of the latent variable in the subpopulation of examinees with a zero score on all items, and item-scaling parameters. Due to this closed-form expression, all parameters of the random effects generalized partial credit model can be estimated using marginal maximum likelihood estimation without assuming a particular distribution of the latent variable in the population of examinees and without using numerical integration. Also due to this closed-form expression, new special cases of the random effects generalized partial credit model can be identified. In addition to these new special cases, a slightly more general model than the random effects generalized partial credit model is presented. This slightly more general model is called the extended generalized partial credit model. Attention is paid to maximum likelihood estimation of the parameters of the extended generalized partial credit model and to assessing the goodness of fit of the model using generalized likelihood ratio tests. Attention is also paid to person parameter estimation under the random effects generalized partial credit model. It is shown that expected a posteriori estimates can be obtained for all possible score patterns. A simulation study is carried out to show the usefulness of the proposed models compared to the standard models that assume normality of the latent variable in the population of examinees. In an empirical example, some of the procedures proposed are demonstrated.     

An empirically derived scoring system for intermale aggression in mice

Scoring systems used to assess intermale aggression have been characterized by arbitrary scales and wide variability in the behaviors selected for measurement. The use of such different systems severely limits the ability of investigators to make meaningful comparisons among studies and indicates that there is a need for a common, statistically derived evaluative system for intermale aggression. We measured the frequency and duration of five major components of agonistic behavior exhibited by intact males toward olfactory bulbectomized stimulus males and then analyzed the data using a number of univariate and multivariate procedures. The results were used to generate two statistically based scoring systems, one a short-form index and the other a composite index for more detailed studies of aggression. It is hoped that these statistically derived systems will be adopted by other investigators to increase methodological congruence in the field.     

PyParse: A semiautomated system for scoring spoken recall data

Studies of human memory often generate data on the sequence and timing of recalled items, but scoring such data using conventional methods is difficult or impossible. We describe a Python-based semiautomated system that greatly simplifies this task. This software, called PyParse, can easily be used in conjunction with many common experiment authoring systems. Scored data is output in a simple ASCII format and can be accessed with the programming language of choice, allowing for the identification of features such as correct responses, prior-list intrusions, extra-list intrusions, and repetitions.     

A proposal for a new system of credit allocation in science

This essay discusses some of the problems with current authorship practices and puts forward a proposal for a new system of credit allocation: in published works, scientists should more clearly define the responsibilities and contributions of members of research teams and should distinguish between different roles, such as author, statistican, technician, grant writer, data collector, and so forth. Dr. Resnik is an Associate Professor of Philosophy and Director of the Center for the Advancement of Ethics, University of Wyoming. Information is available on website: http://www.uwyo.edu/bu/acct/cae.htm     

Revised scoring system and norms for the Physical Activity Stereotyping Index.

Protocols of 768 children, ages 6 to 12 years, provided the basis for revision of scoring and development of norms.     

Personal problem-solving system for scoring TAT responses: preliminary validity and reliability data

Personal problem solving has emerged as an important construct in the cognitive-behavioral literature, yet there is a lack of clinically useful, performance-based measures practitioners can use to assess the personal problem-solving skills of their clients. Two studies evaluated the validity and reliability of a scoring system for measuring personal problem-solving processes via the Thematic Apperception Test (TAT; Morgan & Murray, 1935). In Experiment 1, undergraduate students (N = 87) completed two measures of personal problem solving, as well as three TAT cards, which were scored using the Personal Problem-Solving System (PPSS; Renan, 1990). In Experiment 2, an additional group of undergraduates (N = 56) responded to three TAT cards on two separate occasions and also completed a different measure of personal problem solving. Results from both studies supported the use of the PPSS for scoring TAT responses to assess personal problem-solving processes. Suggestions for future research are highlighted.     

A camera-based scoring system for evaluating performance accuracy during a golf putting task

Golf putting accuracy is often evaluated by measuring the distance that the ball finishes from the hole. However, accuracy is a function of line and length, and distance-from-hole measures confound these two factors. A scoring system for evaluating putting accuracy is described that enables the efficient measurement of errors in line and length. A camera placed above the hole takes digital photographs of the final position of the ball. A custom-developed program written in the National Instruments LabVIEW graphical programming language derives a variety of accuracy measures from these photographs, including distance from the hole, angle of error, distance short or long from the hole, and distance left or right from the hole. Evaluation of the system indicated that the measures were as accurate as manual measurements and were reliable when rescored on separate occasions. The camera-based scoring system presents a number of advantages in the evaluation of putting accuracy and may be extended to examine performance in other sports. The ScorePutting program may be downloaded from the Psychonomic Society's Archive of Norms, Stimuli, and Data, www.psychonomic.org/archive.     

Decision making under internal uncertainty: the case of multiple-choice tests with different scoring rules

This paper assesses framing effects on decision making with internal uncertainty, i.e., partial knowledge, by focusing on examinees' behavior in multiple-choice (MC) tests with different scoring rules. In two experiments participants answered a general-knowledge MC test that consisted of 34 solvable and 6 unsolvable items. Experiment 1 studied two scoring rules involving Positive (only gains) and Negative (only losses) scores. Although answering all items was the dominating strategy for both rules, the results revealed a greater tendency to answer under the Negative scoring rule. These results are in line with the predictions derived from Prospect Theory (PT) [Econometrica 47 (1979) 263]. The second experiment studied two scoring rules, which allowed respondents to exhibit partial knowledge. Under the Inclusion-scoring rule the respondents mark all answers that could be correct, and under the Exclusion-scoring rule they exclude all answers that might be incorrect. As predicted by PT, respondents took more risks under the Inclusion rule than under the Exclusion rule. The results illustrate that the basic process that underlies choice behavior under internal uncertainty and especially the effect of framing is similar to the process of choice under external uncertainty and can be described quite accurately by PT.     

Decision processes in verifying category membership statements: Implications for models of semantic memory

Current models of semantic memory assume that natural categories are well-defined. Specific predictions of two such models, the Smith, Shoben, and Rips (1974a) two-stage feature comparison model and the Glass and Holyoak (1974/75) ordered search model, were tested and disconfirmed in Experiment I. We propose an alternative model postulating fuzzy categories represented as sets of characteristic properties. This model, combined with a Bayesian decision process, accounts for the results of three additional experiments, as well as for the major findings in the semantic memory literature. We argue that people verify category membership statements by assessing similarity relations between concepts rather than by using information which logically specifies the truth value of the sentence. Our data also imply that natural categories are fuzzy rather than well-defined.     

Derivation and application of a unit scoring system for the strong vocational interest blank for women

Scoring keys, based upon unit weights, were made up for fourteen occupations of theStrong Vocational Interest Blank for Women. The study here presented of scores obtained in using these keys, in comparison with scores obtained from Dr. Strong's keys, indicates, for 551 women at the University of Rochester, that the new, unit-weighted keys are valid for all practical purposes and make possible a great saving in scoring time.