Response data containing an excessive number of zeros are referred to as zero-inflated data. When differential item functioning (DIF) detection is of interest, zero-inflation can attenuate DIF effects in the total sample and lead to underdetection of DIF items. The current study presents a DIF detection procedure for response data with excess…

De la Torre and Deng suggested a resampling-based approach for person-fit assessment (PFA). The approach involves the use of the [math equation unavailable] statistic, a corrected expected a posteriori estimate of the examinee ability, and the Monte Carlo (MC) resampling method. The Type I error rate of the approach was closer to the nominal level…

It is more common for educational and psychological data to be nonnormal than to be approximately normal. This tendency may lead to bias and error in point estimates of the Pearson correlation coefficient. In a series of Monte Carlo simulations, the Pearson correlation was examined under conditions of normal and nonnormal data, and it was compared…

This paper presents the Agresti & Coull "Adjusted Wald" method for computing confidence intervals and margins of error for common proportion estimates. The presented method is easily implementable by business students and practitioners and provides more accurate estimates of proportions particularly in extreme samples and small…

Although SAS PROC CALIS is not designed to perform multigroup comparisons, it is believed that SAS can be "tricked" into doing so for groups of equal size. At present, there are no comprehensive examples of the steps involved in performing a multigroup comparison in SAS. The purpose of this article is to illustrate these steps. We demonstrate…

For two random variables, X and Y, let D = X - Y, and let theta[subscript x], theta[subscript y], and theta[subscript d] be the corresponding medians. It is known that the Wilcoxon-Mann-Whitney test and its modern extensions do not test H[subscript o] : theta[subscript x] = theta[subscript y], but rather, they test H[subscript o] : theta[subscript…

Stability of Type I error rates and power are investigated for three forms of the Box test and two forms of the jackknife test with equal and unequal sample sizes under conditions of normality and nonnormality. The Box test is shown to be robust to violations of the assumption of normality when sampling is from leptokurtic populations. The…

Error profiles for the Fall Enrollment Survey of the Higher Education General Information Survey (HEGIS) were developed as part of an assessment of the quality of survey data. Three statistics were of particular interest: the count of full-time equivalent students, the breakdown by race/ethnicity, and the count of unclassified students. Attention…

This report reviews some ostensibly conflicting empirical findings which have been reported in conjunction with Elkind's (1967) conjecture that Piaget's conservation problems tap two distinct concepts. The discrepant findings which report on the order of emergence of identity conservation and equivalence conservation are discussed. An analysis of…

For one important set of data, namely, the data on unemployment and employment collected by the Census Bureau in its monthly Current Population Survey (CPS), some information on nonsampling error is available that can be used to evaluate the regularly reported labor force figures. The paper is concerned with the nonsampling error that relates…

Because public opinion polls have become important sources of information for legislators and politicians, public opinion pollsters should carefully consider the relationships between gender wording of polling questions, measurement errors, and validity and generalizability of survey findings. Findings from numerous research projects indicate that…