Research designs that include planned missing data are gaining popularity in applied education research. These methods have traditionally relied on introducing missingness into data collections using the missing completely at random (MCAR) mechanism. This study assesses whether planned missingness can also be implemented when data are instead…

Meta-analysis is a statistical method that is increasingly utilized to combine and compare the results of previous primary studies. However, because of the lack of comprehensive guidelines for how to use meta-analysis, many meta-analysis studies have failed to consider important aspects, such as statistical programs, power analysis, publication…

This article tackles the problem of what should be done with real textual data that are contaminated by errors of recording, particularly when the data contain words that are misspelt, unintentionally or otherwise. (Contains 5 tables and 2 figures.)

Purpose: The purpose of this study was to investigate the characteristics of missing physical activity (PA) data of children and youth. Method: PA data from the Chinese City Children and Youth Physical Activity Study ("N" = 2,758; 1,438 boys and 1,320 girls; aged 9-17 years old) were used for the study. After the data were sorted by the…

Resampling methods including randomization test, cross-validation, the jackknife and the bootstrap are widely employed in the research areas of natural science, engineering and medicine, but they lack appreciation in educational research. The purpose of the present review is to revisit and highlight the key principles and developments of…

Research in fields other than education has found that studies with small sample sizes tend to have larger effect sizes than those with large samples. This article examines the relationship between sample size and effect size in education. It analyzes data from 185 studies of elementary and secondary mathematics programs that met the standards of…

Good quality data is paramount for applied economic research. If the data are distorted, corresponding conclusions may be incorrect. We demonstrate how Benford's law, the distribution that first digits of numbers in certain data sets should follow, can be used to test for data abnormalities. We conduct an analysis of nine commonly used data sets…

Secondary data analysis as a methodological approach is not without its critics. Indeed, three main objections to the use of secondary data analysis in social research stand out: first that because of the socially constructed nature of social data, the act of reducing it to a simple numeric form cannot fully encapsulate its complexity. Secondly,…

This article presents the author's address at the 2007 "Journal of Applied Quantitative Methods" ("JAQM") prize awarding festivity. The festivity was included in the opening of the 4th International Conference on Applied Statistics, November 22, 2008, Bucharest, Romania. In the address, the author reflects on three theses that…

Classic parametric statistical significance tests, such as analysis of variance and least squares regression, are widely used by researchers in many disciplines, including psychology. For classic parametric tests to produce accurate results, the assumptions underlying them (e.g., normality and homoscedasticity) must be satisfied. These assumptions…

In some linear regression problems samples may be unwittingly drawn from a heterogeneous population. The exploratory procedure described in this paper can be used to detect heterogeneity in a regression problem associated with the intercept. (Author)

A recurrent problem in assessment work is to determine the degree of match for a client score profile to some known prototypic group patterns. It is more accurate to conceptualize the "known" group pattern as a range of values. Interval-banded profile analysis represents a generalization of the method of centours to this problem.…

Addresses issue of range enhancement effects on correlations, asserting that, while adding to or deleting from sample can affect variance and correlation in sample, increases or decreases in individual differences in intact sample resulting from such factors as history, maturation, training, and experience will not necessarily affect correlations.…

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)

Canonical correlation analysis is illustrated and three common fallacious interpretation practices are described. Simply, canonical correlation is an example of the bivariate case. Like all parametric methods, it involves the creation of synthetic scores for each person. It presumes at least two predictor variables and at least two criterion…