The purpose of this paper is to clarify the seemingly discrepant views of test theorists and test developers about terminology related to the evaluation of test content. The origin and evolution of the concept of content validity are traced, and the concept is reformulated in a way that emphasizes the notion that content domain definition,…

Differential item functioning (DIF), or item bias, occurs when individuals in a focal group respond differently to a test item than do individuals in a reference group even when comparisons are restricted to individuals with similar overall skill levels on the trait in question. It is common in constructing a questionnaire or survey to recommend…

Modified Parallel Analysis (MPA) is a heuristic method for assessing "approximate unidimensionality" of item pools. It compares the second eigenvalue of the observed correlation matrix with the corresponding eigenvalue extracted from a "parallel" matrix generated by a unidimensional and locally independent model. Revised…

A study examined the perceptions of pharmacy students regarding pharmacist-patient communication to determine whether the increased emphasis on the patient counseling role of pharmacists resulted in perceptual differences between students, pharmacists, and faculty. Data were gathered from 25 students, 2 pharmacy faculty, 8 communication studies…

This study of survey research experts was conducted to determine desirable characteristics of mail questionnaires. The 82-item Likert-scale instrument used in the study covered general appearance, instructions, choice of items, choice of response options, wording, order of items, and item format. The instrument was administered to: 8 subjects who…

Language testing is an area of applied linguistics that combines the exercise of professional judgment about language, learning, and the nature of the achievement of language learning with empirical data about student performance and, by inference, their abilities. The relationship between judgments and empirical data in language testing is…

The Mantel-Haenszel (MH) procedure attempts to identify and quantify differential item performance (item bias). This paper summarizes the MH statistics, and identifies the parameters they estimate. An equivalent procedure based on the Rasch model is described. The theoretical properties of the two approaches are compared and shown to require the…

Techniques derived from item response theory are useful for estimating the reliability of test classification above and below the cutting score. Test developers can construct a test whose information is peaked in the region of the cutting score; users can select a test which provides the most information in this region. The Cut-Score…

An item discriminability study of the Iowa Tests of Basic Skills Language Skills tests identified test items that are robust discriminators, psychometrically capable of separating low scorers from higher scorers in the language tests battery. The analysis was conducted by calculating a point-biserial correlation for each item on the four language…

A study was undertaken to provide a factor analysis of the Omega Scale, a 25-item, Likert-type scale developed in 1984 to assess attitudes toward death and funerals and other body disposition practices. The Omega Scale was administered to 250 students enrolled in introductory psychology classes at two higher education institutions in Alabama.…

This research investigated the effect on estimated lower asymptotes of the instructions to Graduate Record Examination (GRE) examinees about how the test would be scored. This effect was assessed for four different verbal item types (analogies, antonyms, sentence completion, and reading comprehension) using a two-way, unweighted means analysis of…

The definition of differential item performance (DIP), often referred to as item bias, is discussed. DIP is suggested as a comprehensive term to encompass item bias (item invalidity which is unfair to certain population subgroups) and instructional bias (a valid reflection of group differences in instruction or background). This study investigated…

The purpose of this paper is to further the cause of clarifying construct interpretations of tests, by proposing that non-metric multidimensional scaling may be more useful than factor analysis or other latent structure models for investigating the internal structure of tests. It also suggests that typical problems associated with scaling…

An investigation of the effect on the difficulty value of an item due to position placement within a test was made. Using a 60-item operational test comprised of 5 subtests, 60 items were placed as experimental items on a number of spiralled test forms in three different positions (first, middle, last) within the subtest composed of like items.…