Chalmers recently published a critique of the use of ordinal a[alpha] proposed in Zumbo et al. as a measure of test reliability in certain research settings. In this response, we take up the task of refuting Chalmers' critique. We identify three broad misconceptions that characterize Chalmers' criticisms: (1) confusing assumptions with…

The main points of Sijtsma and Green and Yang in Educational Measurement: Issues and Practice (34, 4) are that reliability, internal consistency, and unidimensionality are distinct and that Cronbach's alpha may be problematic. Neither of these assertions are at odds with Davenport, Davison, Liou, and Love in the same issue. However, many authors…

Ultimately, measures in research, testing, assessment and evaluation are used, or have implications, for ranking, intervention, feedback, decision-making or policy purposes. Explicit recognition of this fact brings the often-ignored and sometimes maligned concept of consequences to the fore. Given that measures have personal and social…

In this webinar, Dr. Ronald Ferguson, creator of the Tripod Project and Senior Lecturer at Harvard University Graduate School of Education, discussed the use of student surveys as an approach to measuring teacher effectiveness. This Q&A addressed the questions participants had for Dr. Ferguson following the webinar. The webinar recording and…

A response is made to a paper that urges the use of the Rasch model for educational assessment. This paper argues that the model is inadequate and that claims for its efficacy are exaggerated and technically weak.

In this webinar, Dr. Drew Gitomer, professor at Rutgers University, shared results from recent studies of classroom observations that helped participants understand both general findings about the qualities of classroom interactions and also the challenges to carrying out valid and reliable observations. This Q&A addressed the questions…

In this commentary, we offer a set of visual tools that can assist education researchers, especially those in the field of mathematics, in developing cohesiveness from a mixed methods perspective, commencing at a study's research questions and literature review, through its data collection and analysis, and finally to its results. This expounds…

The "Parenting Stress Index, Fourth Edition" (PSI-4) is a 120-item measure used to explore parental stress levels considering a parent's relationship with one of his or her children between the ages of 1 month and 12 years. The main purpose of the test is to define these stress levels and from where they originate in order to identify…

Cooper et al. (this issue) develop an interactive activation model of spatial and imitative compatibilities that simulates the key results from Catmur and Heyes (2011) and thus conclude that both compatibilities are mediated by the same processes since their single model can predict all the results. Although the model is impressive, the…

This commentary on the article titled "Examining the Internal Structure Evidence for the Performance Assessment for California Teachers: A Validation Study of the Elementary Literacy Teaching Event for Tier 1 Teacher Licensure" provides an overview of Performance Assessment for California Teachers (PACT), its relationship to edTPA and…

Assessments used for both clinical practice and research should show evidence of validity and reliability for the target group of people. It is easy to agree with this statement, but it is not always easy to choose the right assessment for the right purpose. Recently there have been increasing numbers of studies which investigate further the…

There are three fundamental problems in Sijtsma ("Psychometrika," 2008): (1) contrary to the name, the glb is not the greatest lower bound of reliability but rather is systematically less than omega[subscript t] (McDonald, "Test theory: A unified treatment," Erlbaum, Hillsdale, 1999), (2) we agree with Sijtsma that when considering how well a test…

This discussion paper argues that both the use of Cronbach's alpha as a reliability estimate and as a measure of internal consistency suffer from major problems. First, alpha always has a value, which cannot be equal to the test score's reliability given the inter-item covariance matrix and the usual assumptions about measurement error. Second, in…

The best education no doubt comes from a student staying in one school system from elementary to high school. Some students are fortunate to have a consistent education; some are not as fortunate. Continuity in instruction, learner outcomes, emotional stability, and social relationships prevail when students live in one location as long as…

Clinical judgment is foundational to psychological practice. Accurate judgment forms the basis for establishing reasonable goals and selecting appropriate treatments, which in turn are essential in achieving positive therapeutic outcomes. Therefore, Spengler and colleagues' meta-analytic finding--clinical judgment accuracy improves marginally with…