Outlier Measures and Norming Methods for Computerized Adaptive Tests

2001 ◽  
Vol 26 (1) ◽  
pp. 85-104 ◽  
Author(s):  
Eric T. Bradlow ◽  
Robert E. Weiss
Keyword(s):  
Stopping Rules ◽  
P Value ◽  
Sequential Choice ◽  
Probability Scale ◽  
Adaptive Tests ◽  
Computerized Adaptive Tests ◽  
Paper And Pencil ◽  
Highly Correlated

The problem of identifying outliers has two important aspects: the choice of outlier measures and the method to assess the degree of outlyingness (norming) of those measures. Several classes of measures for identifying outliers in Computerized Adaptive Tests (CATs) are introduced. Some of these measures are new and are constructed to take advantage of CATs’ sequential choice of items; other measures are taken directly from paper and pencil (P&P) tests and are used for baseline comparisons. Assessing the degree of outlyingness of CAT responses, however, can not be applied directly from P&P tests because stopping rules associated with CATs yield examinee responses of varying lengths. Standard outlier measures are highly correlated with the varying lengths which makes comparison across examinees impossible. Therefore, four methods are presented and compared which map outlier statistics to a familiar probability scale (a p value). The application of these methods to CAT data is new. The methods are explored in the context of CAT data from a 1995 Nationally Administered Computerized Examination (NACE).

scholarly journals Making Fixed-Precision Between-Item Multidimensional Computerized Adaptive Tests Even Shorter by Reducing the Asymmetry Between Selection and Stopping Rules

2020 ◽  
Vol 44 (7-8) ◽  
pp. 531-547
Author(s):  
Johan Braeken ◽  
Muirne C. S. Paap
Keyword(s):  
Fisher Information ◽  
Stopping Rule ◽  
Stopping Rules ◽  
Item Selection ◽  
Test Length ◽  
Objective Criterion ◽  
Current Generation ◽  
Adaptive Tests ◽  
Selection Rules ◽  
Computerized Adaptive Tests

Fixed-precision between-item multidimensional computerized adaptive tests (MCATs) are becoming increasingly popular. The current generation of item-selection rules used in these types of MCATs typically optimize a single-valued objective criterion for multivariate precision (e.g., Fisher information volume). In contrast, when all dimensions are of interest, the stopping rule is typically defined in terms of a required fixed marginal precision per dimension. This asymmetry between multivariate precision for selection and marginal precision for stopping, which is not present in unidimensional computerized adaptive tests, has received little attention thus far. In this article, we will discuss this selection-stopping asymmetry and its consequences, and introduce and evaluate three alternative item-selection approaches. These alternatives are computationally inexpensive, easy to communicate and implement, and result in effective fixed-marginal-precision MCATs that are shorter in test length than with the current generation of item-selection approaches.

The Semantic Differential as an Index of Traffic Sign Perception and Comprehension

1977 ◽  
Vol 19 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Robert E. Dewar ◽  
Jerry G. Ells
Keyword(s):  
Semantic Differential ◽  
The Other ◽  
Traffic Sign ◽  
Two Factors ◽  
Valid Instrument ◽  
Paper And Pencil ◽  
Verbal Messages ◽  
Highly Correlated

There is a need to develop and validate simple, inexpensive techniques for the evaluation of traffic sign messages. This paper examines the semantic differential (a paper-and-pencil test which measures psychological meaning) as a potential instrument for such evaluation. Two experiments are described, one relating semantic differential scores to comprehension and the other relating this index to glance legibility. The data indicate that semantic differential scores on all four factors (evaluative, activity, potency, and understandability) were highly correlated with comprehension of symbolic messages. These scores were unrelated to glance legibility of verbal messages, but two factors (evaluative and understandability) did correlate with glance legibility of symbolic messages. It was concluded that the semantic differential is a valid instrument for evaluating comprehension of symbolic sign messages and that it has advantages over other techniques.

scholarly journals Doppler evaluation of the fetal pulmonary artery pressure

2019 ◽  
Vol 47 (2) ◽  
pp. 218-221
Author(s):  
Alberto Sosa-Olavarria ◽  
Jesús Zurita-Peralta ◽  
Claudio V. Schenone ◽  
Mauro H. Schenone ◽  
Fernando Prieto
Keyword(s):  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Main Pulmonary Artery ◽  
P Value ◽  
Review Of The Literature ◽  
Artery Pressure ◽  
Bivariate Correlation ◽  
Highly Correlated ◽  
Doppler Evaluation

Abstract Background The Doppler effect has allowed the characterization of several vessels in maternal-fetal circulation that have been used for practical purposes. Our review of the literature showed a paucity of information about fetal pulmonary artery pressure (FMPAP) and its behavior in regard to gestational age (GA). The objectives of the study were to evaluate a formula to calculate the main FMPAP and its correlation with GA. Methods A total of 337 fetuses without obvious pathology were studied prospectively using Doppler evaluation of the FMPAP. Using the fetal main pulmonary artery Doppler acceleration time (FMPAT), we obtained the FMPAP using the following formula: FMPAP=90 – (0.62×FMPAT). Regression analyses, Pearson’s bivariate correlation and paired sample t-test were used when appropriate. Results FMPAT increases while FMPAP decreases with GA. Pearson’s correlation coefficient for FMPAP and GA was −0.544 (P-value<0.001) and for FMPAT and GA was 0.556 (P-value<0.001). FMPAP and FMPAT were highly correlated (R=−0.972; P<0.001). Conclusion Pulmonary artery pressure in the fetus decreases with GA.

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