Best Practices in Utilizing the Changing Criterion Design.

The changing criterion design (CCD) has been a recognized format of single-case research for four decades. Published examples of the CCD have been limited and the structure of the design used in the literature has varied to a degree that might engender confusion. This review examines the structure of CCD studies published to date to identify prior implementation practices and identify best practices for future use.

Psychometric properties of the Pyramids and Palm Trees Test.

The Pyramids and Palm Trees Test (PPT) is a nonverbal measure of semantic memory that has been frequently used in previous aphasia, agnosia, and dementia research. Very little psychometric information regarding the PPT is available. The purpose of this study was to investigate the psychometric properties of the PPT in a population of healthy college students. Results indicated that the PPT achieved poor test-retest reliability, failed to obtain adequate internal consistency, and demonstrated poor convergent validity, but showed acceptable discriminant validity. The results of this study suggest that the PPT lacks acceptable reliability and validity for use with a college student population.

The word reading test of effort in adult learning disability: a simulation study.

The Word Reading Test (WRT) was designed to detect effort problems specific to a learning disability sample. The WRT and the Word Memory Test (WMT) were administered to two simulator and normal control groups. The WRT showed excellent receiver operating characteristics (e.g., 90% sensitivity and 100% positive predictive power) and outperformed the WMT in detecting both reading and mental speed simulators. This finding and a double dissociation between reading and speed simulators on WRT errors and reaction time suggested specific effort effects while poor effort of simulators on the WMT suggested general effort effects. Results are supportive of the WRT as a potential effort indicator in learning disability.