A jack knife is a pocket knife that is put to many tasks, because it's ready to hand. Often there could be a better tool for the job, such as a screwdriver, a scraper, or a can-opener, but these are not usually pocket items. In statistical terms, the expression implies making do with what's available. Another simile, of an extreme situation, is…

DIMTEST is a statistical test procedure for assessing essential unidimensionality of binary test item responses. The test statistic T used for testing the null hypothesis of essential unidimensionality is a nonparametric statistic. That is, there is no particular parametric distribution assumed for the underlying ability distribution or for the…

Empirical Bayes methods are shown to provide a practical alternative to standard least squares methods in fitting high dimensional models to sparse data. An example concerning prediction bias in educational testing is presented as an illustration. (Author)

The 13 basic Minnesota Multiphasic Personality Inventory (MMPI) scales, 21 experimental scales of hostility and control, and four response-bias scales are cross-validated on 168 male criminals assigned to four aggressive criterion groups (nonviolent, threat, battery, and homicide). (Author)

A small data set is used to show that correlations and standard deviations measured within an explicitly selected group need not be smaller than those within an applicant population. Both validity and reliability estimates within a selected group can exceed those within an applicant population. (Author/LMO)

Compared two types of empirical study with two types of conceptual research on the validity of the Rorschach. Argues that the Rorschach does have some validity and that poor research is at least partly culpable for the Rorschach's perceived failure. (Author/BL)

Rorschach protocols of all inpatients since 1960 known to have committed suicide either during or subsequent to hospitalization (n=12) are compared with the Rorschach protocols of a closely matched control group. The results suggest that the presence of transparency and cross-sectional representations is a reliable indicator of suicidal intent.…

The purpose of this paper was to research published validity reports of the Multiple Assessment and Program Services (MAPS) Test and to conduct quantitative analysis on the validity coefficients from the MAPS reports to determine the generalizability of the results and to identify which variables in the reports impact these coefficients. The…

A simple quasi-experimental design is described which may have utility in a variety of applied and laboratory research settings where ordinarily the one-group pretest-posttest pre-experimental design might otherwise be the procedure of choice. The design approaches the internal validity of true experimental designs while optimizing external…

The estimation of values of a latent-trait presumed to underlie a given set of item response data is made on the basis of dichotomously scored items utilizing the so-called "normal ogive model" of Lawley and Lord. This model provides an internal scale of measurement, scores which are independent of the particular test items employed, individual…

For the purpose of obtaining data to use in test development, multiple matrix sampling plans were compared to examinee sampling plans. Data were simulated for examinees, sampled from a population with a normal distribution of ability, responding to items selected from an item universe. (Author/LMO)

The authors suggest that there may be a phenomenon of posttest sensitization which could affect the generalizability of experimental results in the way that pretest sensitization does. A quasi-experimental design is proposed to test for such a phenomenon. (JKS)

In order to clarify the concurrent validity of the Peabody Individual Achievement Test (PIAT) and the Metropolitan Achievement Test (MAT), product-moment correlations were computed for all subscores and total scores for 26 normal-range public school third-grade girls and boys. (Author)

We are concerned with the hypothesis that two variables have a perfect disattenuated correlation, hence measure the same trait except for errors of measurement. This hypothesis is equivalent to saying, within the adopted model, that true scores of two psychological tests satisfy a linear relation. A statistical test of this hypothesis is derived…

Three frequently used response formats are compared via analysis of covariance structures. The cumulative results based on four data sets provided evidence inconsistent with previous research suggesting that these formats are interchangeable. The semantic-differential format is most preferred while in most cases the Stapel format is least…