Criteria are briefly proposed for final conclusions, research problems, and research hypotheses in quantitative research. Moreover, based on a proposed definition of applied and basic/general research, it is argued that (1) in applied quantitative research, while research problems are necessary, research hypotheses are unjustified, and that (2) in…

Missing data is a common challenge to any researcher in almost any field of research. In particular, human participants in research do not always respond or return for assessments leaving the researcher to rely on missing data methods. The most common methods (i.e., Multiple Imputation and Full Information Maximum Likelihood) assume that the…

Regression discontinuity design (RD) has been widely used to produce reliable causal estimates. Researchers have validated the accuracy of RD design using within study comparisons (Cook, Shadish & Wong, 2008; Cook & Steiner, 2010; Shadish et al, 2011). Within study comparisons examines the validity of a quasi-experiment by comparing its…

The sharp regression discontinuity design (RDD) has three key weaknesses compared to the randomized clinical trial (RCT). It has lower statistical power, it is more dependent on statistical modeling assumptions, and its treatment effect estimates are limited to the narrow subpopulation of cases immediately around the cutoff, which is rarely of…

This paper compares five growth measures using the High School and Beyond database. The measures are: (1) simple gain (posttest minus pretest); (2) difference between group means; (3) percentage of students who scored higher on the posttest than the pretest; (4) percentage of items missed on the pretest which are subsequently answered correctly on…

A meta-analysis of outcomes from 32 studies investigating pretest effects was conducted. For all outcomes the average effect size was +.22, indicating an elevating effect of pretest on posttest. Duration of time between pre- and posttesting was also related to effect size. Researchers should continue to include pretest as a design variable.…

This paper delineates conditions under which the use of change scores will not produce misleading results, and may perhaps be preferable to other methods of analysis. The validity of change scores in randomized pretest-posttest designs is discussed along with situations where analysis of change scores should be used. (Author/GK)

Problems associated with the analysis of data collected using the Solomon Four Group Design are discussed. The design includes an experimental group and a control group that have been pretested and posttested, and an experimental and a control group that have been posttested only. A sample problem is approached in three different ways. First, the…

An explicit model identifying 10 relevant components of achievement gain scores has been developed. Based on that model, all students under consideration are stratified according to individual observed pretest score, and achievement gains are measured relative to the average and range of gains among students in the same prescore stratum. The…

This review critiques the use of Lev Vygotsky's concept of the zone of proximal development (ZPD) in quantitative research that focuses on the role communication plays in learning. A study that makes claims in terms of the ZPD should include a pretest, a problem-solving activity, and a posttest. Without these minimal elements, researchers are not…

The purpose of this study was to determise the relative loss in statistical power of traditional methods of analysis when response-shift bias is present. Five methods of analysis (posttest scores only; postminus pretests; postminus retrospective pretest; postcovaried by pretest; postcovaried by retrospective pretest) were compared. (Author/BW)

The norm-referenced evaluation model (RMC Model A) for Title I project evaluation, consists of procedures whereby the expected posttest standing of a treatment group under the null condition is generated from their pretest standing. It is assumed that the treatment group is not selected on the basis of their pretest scores and can be considered…

When two groups, initially dissimilar, undergo different treatments, can subsequent differences be partitioned in such a way that the difference between the two treatments is unbiased? This is the central problem of this paper, and it is confronted by the examination of two levels of information using a Follow Through Evaluation. The first…