The dependence of item discrimination index (D) on item difficulty index (p), and the relationship of D and p to the phi coefficient are delineated. A table of critical values of D significant at the .10 and .05 levels, with p ranging from .10 to .90, is presented. (Author/CTM)

A procedure is discussed for testing the significance of the difference in two correlated correlation coefficients, using Fisher's Z-Transformation. The procedure is applicable to a wide range of problems involving tests between dependent correlations and has documented mathematical support when its power curves are examined. (MH)

True effects of the joint dichotomization of two variables are explored, and implications of the correct formulation for generalizations of the results obtained by S. E. Maxwell and H. D. Delaney (1993) are examined. The inflation of apparent effects can occur when only one or two predictor variables is dichotomized. (SLD)

Reviewed statistics textbooks published since 1995 to determine the treatment of effect sizes and statistical significance tests. Each of the 89 textbooks included statistical significance, while only 60 included information on effect sizes. (SLD)

Studied a major problem with null hypothesis significance testing (NHST) and two common misconceptions about NHST and considered how these issues are treated in 12 recent textbooks used in education research methods and statistics classes. Findings show that almost all textbooks do not acknowledge controversies surrounding NHST. (SLD)

Explains that an initial criterion to determine severe discrepancies and relative strengths and weaknesses is significant difference between regressed standard scores. Presents tables as convenient method to determine magnitude of discrepancy required for significance at common reliability and intercorrelation values. Shows prevalences of…

Although stated objectives of multivariate multiple regression and canonical correlation seem different, aspects of the analyses themselves are mathematically equivalent. A numerical example of the similarities is given, with reference to omnibus significance testing, variable weighting schemes, and dimension reduction analysis. (SLD)

D. Trafimow presented an analysis of null hypothesis significance testing (NHST) using Bayes's theorem. Among other points, he concluded that NHST is logically invalid, but that logically valid Bayesian analyses are often not possible. The latter conclusion reflects a fundamental misunderstanding of the nature of Bayesian inference. This view…

Effect sizes (e.g., Cohen's d, Glass's [delta], [[eta] [squared]], adjusted [R [squared]], [[omega] [squared]]) quantify the extent to which sample results diverge from the expectations specified in the null hypothesis. The present article addresses 5 related questions, First, is the advocacy for reporting and interpreting effect sizes part of the…

Curriculum materials designed to provide students with practice interpreting plotted evidence of global climate change were developed using graphs from the scientific literature and tested with one hundred urban high school students from a high-poverty school in a major northern city in the US. The graph interpretation lessons followed a…

There is a distinct divide between theory and practice in American science education. Research indicates that a constructivist philosophy, in which students construct their own knowledge, is conductive to learning, while in many cases teachers continue to present science in a more traditional manner. This study sought to explore possible…

The purpose of this mixed methods study was to examine the impact that a teacher-guided library selection program had on overall reading scores and how this program may or may not promote reading improvement of fourth-grade students at a small suburban school in western New York. Forty fourth graders were used as the sample population, which was…

This study evaluated the predictive validity of two preemployment screening devices--the Urban Teacher Perceiver Interview and the Academic Skills Assessment portion of the Praxis Series test--as used by an urban high-need and hard-to-staff school district. Specifically, we compared predictor scores with subsequent teacher assessment scores…

The purpose of this study was to determine the extent to which a non-traditional strength training program will impact the health-related fitness of youth. Researchers hypothesized that the strengthening program would positively affect the fitness outcomes. Participant physical education classes incorporated strengthening exercises three days…

This article investigates budget monitoring and control in township schools in South Africa. The enactment of the Schools Act 1996 revolutionized school financial management in South Africa, making it part of the drive for democratic school governance. School governing bodies had to be established, whose responsibility it became to manage finances…