Graphical model validation techniques for linear normal models are often used to check the assumptions underlying a statistical model. We describe an approach to provide "instant experience" in looking at a graphical model validation plot, so it becomes easier to validate if any of the underlying assumptions are violated.

Nonoverlap is widely used as a statistical summary of data; however, these analyses rarely correct unwanted positive baseline trend. This article presents and validates the graph rotation for overlap and trend (GROT) technique, a hand calculation method for controlling positive baseline trend within an analysis of data nonoverlap. GROT is…

Visual display of reported impacts is a valuable aid to both reviewers and readers of systematic reviews. Forest plots are routinely prepared to report standardised effect sizes, but where standardised effect sizes are not available for all included studies a forest plot may misrepresent the available evidence. Tabulated data summaries to…

This research suggests that structural accommodation can be implemented during the construction phase of standardized mathematics examinations. Data from a racially diverse district in the United States are used to compare student performance on questions with and without graphical aids. Findings suggest that mathematics questions possessing…

Research on the graphical facilitation of probabilistic reasoning has been characterised by the effort expended to identify valid assessment tools. The authors developed an assessment instrument to compare reasoning performances when problems were presented in verbal-numerical and graphical-pictorial formats. A sample of undergraduate psychology…

This dissertation reports the results of three studies and a pilot study. The first study was a Monte Carlo validation study that examined the accuracy of a new visual inspection method, the semi-interquartile range method. Results of the study indicated that this method had lower levels of power than a previously validated method, the…

Graphs are often conjoined with text passages in history textbooks to help students comprehend complex constructs. Four linkages connect text and graphs: appropriate elements, fitting patterns, suitable labels and causal markers. Graphs in current textbooks contain few such linkages and seldom mirror the construct under study. An experiment…

Presented at the 23rd Annual Historically Black Colleges & Universities (HBCU) Conference in Atlanta, GA, in September 2011. Admitted Class Evaluation Service (ACES) is the College Board's free online service that predicts how admitted students will perform at a college or university generally, and how successful students will be in specific…

This article takes a further look at the percentage of data points exceeding the median (PEM) analysis method for single-case research data, first presented in this journal by Hsen-Hsing Ma. Ma examined the relationship between PEM and the established percentage of nonoverlapping data (PND) and then applied PEM in a meta-analysis of 61 data sets,…

Evaluates the validity of the test used to place students in the comprehension-based courses offered by the Second Language Institute of the University of Ottawa. The test is described in the context of the target student population and the comprehension-based courses. Different factors of evaluating the concurrent and predictive validity were…

The role of the coauthor relationship in the structure of informal communications networks within disciplines is explored, and the validity of coauthor graphs used to map these relationships is tested for both small and large databases. (CLB)

The purpose of this research is to evaluate the effectiveness of the area (homogeneous) scales of the Navy Vocational Interest Inventory (NVII) as predictors of Class "A" school achievement and as measures of rating differentiation by comparing specific occupational scales with more general interest measures--the NVII area scales. The…

A visual display is introduced that enables one to compare the predictive validities of all possible non-negatively weighted sums of two predictors. This two-predictor validity curve assesses the level of predictability of a criterion from composites of two predictors. Derivations are presented for the general case. For illustrative purposes, the…

This study explored some practical issues for single-case researchers who rely on visual analysis of graphed data, but who also may consider supplemental use of promising statistical analysis techniques. The study sought to answer three major questions: (a) What is a typical range of effect sizes from these analytic techniques for data from…

In statistical terms, transfer rates require two components: a numerator that represents community college students who transfer and a denominator that approximates the pool of potential transfer students. The California Task Force adopted a set of criteria to judge the appropriateness of prospective pairs of numerators and denominators. Its form…