TitleConsiderations in Performance Evaluations of Computerized Formative Assessments
Publication TypeConference Paper
Year of Publication2017
AuthorsChajewski, M, Harnisher, J
Conference NameIACAT 2017 Conference
Date Published08/2017
PublisherNiigata Seiryo University
Conference LocationNiigata, Japan
Keywordsalgebra, Formative Assessment, Performance Evaluations

Computerized adaptive instruments have been widely established and used in the context of summative assessments for purposes including licensure, admissions and proficiency testing. The benefits of examinee tailored examinations, which can provide estimates of performance that are more reliable and valid, have in recent years attracted a greater audience (i.e. patient oriented outcomes, test prep, etc.). Formative assessment, which are most widely understood in their implementation as diagnostic tools, have recently started to expand to lesser known areas of computerized testing such as in implementations of instructional designs aiming to maximize examinee learning through targeted practice.

Using a CAT instrument within the framework of evaluating repetitious examinee performances (in such settings as a Quiz Bank practices for example) poses unique challenges not germane to summative assessments. The scale on which item parameters (and subsequently examinee performance estimates such as Maximum Likelihood Estimates) are determined usually do not take change over time under consideration. While vertical scaling features resolve the learning acquisition problem, most content practice engines do not make use of explicit practice windows which could be vertically aligned. Alternatively, the Multidimensional (MIRT)- and Hierarchical Item Response Theory (HIRT) models allow for the specification of random effects associated with change over time in examinees’ skills, but are often complex and require content and usage resources not often observed.

The research submitted for consideration simulated examinees’ repeated variable length Quiz Bank practice in algebra using a 500 1-PL operational item pool. The stability simulations sought to determine with which rolling item interval size ability estimates would provide the most informative insight into the examinees’ learning progression over time. Estimates were evaluated in terms of reduction in estimate uncertainty, bias and RMSD with the true and total item based ability estimates. It was found that rolling item intervals between 20-25 items provided the best reduction of uncertainty around the estimate without compromising the ability to provide informed performance estimates to students. However, while asymptotically intervals of 20-25 items tended to provide adequate estimates of performance, changes over shorter periods of time assessed with shorter quizzes could not be detected as those changes would be suppressed in lieu of the performance based on the full interval considered. Implications for infrastructure (such as recommendation engines, etc.), product and scale development are discussed.

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