JMASM 32: SAS Template for Single-Subject Experimental Designs

Meta-analysis has been used to synthesize research findings and to evaluate the effectiveness of treatments or the accuracy of diagnostic tools. Although meta-analytic techniques were developed to synthesize the results of several studies, controversy exists as to how to quantify the results from singlesubject experimental designs (SSEDs). The most commonly used metrics are reviewed, including nonregression and regression based methods. The application of the SAS template is demonstrated through simulated data sets. The SAS templates can be modified to accommodate a more complex data structure

The Impact of Sample Size in Cross-Classified Multiple Membership Multilevel Models

A simulation study was conducted to examine parameter recovery in a cross-classified multiple membership multilevel model. No substantial relative bias was identified for the fixed effect or level-one variance component estimates. However, the level-two cross-classification multiple membership factor variance components were substantially biased with relatively fewer groups

Investigating the impact of a mixed-format item pool on optimal test designs for multistage testing

textThe multistage testing (MST) has drawn increasing attention as a balanced format of adaptive testing that takes advantages of both fully-adaptive computerized adaptive testing (CAT) and paper-and-pencil (P\&P) tests. Most previous studies on MST have focused on purely dichotomous or polytomous item formats although the mixture of two item types (i.e., mixed-format) provides desirable psychometric properties by combining the strength of both item types. Given the dearth of studies investigating the characteristics of mixed-format MST, the current study conducted a simulation to identify important design factors impacting the measurement precision of mixed-format MST. The study considered several factors-namely, total points (40 and 60), MST structures (1-2-2 and 1-3-3), the proportion of polytomous items (10%, 30%, 50% and 70%), and the routing module design (purely dichotomous and a mixture of dichotomous and polytomous items) resulting in 32 total conditions. A total of 100 replications were performed, and 1,000 normally distributed examinees were generated in each replication. The performance of MST was evaluated in terms of the precision of ability estimation across the wide range of the scale. The study found that the longer test produced greater measurement precision while the 1-3-3 structure performed better than 1-2-2 structure. In addition, a larger proportion of polytomous items resulted in lower measurement precision through the reduced test information during the test construction. The interaction between the large proportion of polytomous items and the purely dichotomous routing module design was identified. Overall, the two factors of test length and the MST structure impacted the ability estimation, whereas the impact of the proportion of polytomous items and routing module design mirrored the item pool characteristic.Educational Psycholog