TitleResponse Time and Response Accuracy in Computerized Adaptive Testing
Publication TypeConference Paper
Year of Publication2017
AuthorsShi, Y
Conference NameIACAT 2017 Conference
Date Published08/2017
PublisherNiigata Seiryo University
Conference LocationNiigata, Japan
KeywordsCAT, response accuracy, Response time

Introduction. This study explores the relationship between response speed and response accuracy in Computerized Adaptive Testing (CAT). CAT provides a score as well as item response times, which can offer additional diagnostic information regarding behavioral processes of task completion that cannot be uncovered by paper-based instruments. The goal of this study is to investigate how the accuracy rate evolves as a function of response time. If the accuracy of cognitive test responses decreases with response time, then it is an indication that the underlying cognitive process is a degrading process such as knowledge retrieval. More accessible knowledge can be retrieved faster than less accessible knowledge. For instance, in reading tasks, the time on task effect is negative and the more negative, the easier a task is. However, if the accuracy of cognitive test responses increases with response time, then the process is of an upgrading nature, with an increasing success rate as a function of response time. For example, problem-solving takes time, and fast responses are less likely to be well-founded responses. It is of course also possible that the relationship is curvilinear, as when an increasing success rate is followed by a decreasing success rate or vice versa.

Hypothesis. The present study argues the relationship between response time on task and response accuracy can be positive, negative, or curvilinear, which depends on cognitive nature of task items holding ability of the subjects and difficulty of the items constant.

Methodology. Data from a subsection of GRE quantitative test were available. We will use generalized linear mixed models. A linear model means a linear combination of predictors determining the probability of person p for answering item i correctly. Modeling mixed effects means both random effects and fixed effects are included. Fixed effects refer to constants across test takers. The models are equivalent with advanced IRT models that go beyond the regular modeling of test responses in terms of one or more latent variables and item parameters. The lme4 package for R will be utilized to conduct the statistical calculation.

Research questions. 1. What is the relationship between response accuracy and response speed? 2. What is the correlation between response accuracy and type of response time (fast response vs slow response) after controlling ability of people?

Preliminary Findings. 1. There is a negative relationship between response time and response accuracy. The success rate declines with elapsing response time. 2. The correlation between the two response latent variables (fast and slow) is 1.0, indicating the time on task effects between respond time types are not different.

Implications. The right amount of testing time in CAT is important—too much is wasteful and costly, too little impacts score validity. The study is expected to provide new perception on the relationship between response time and response accuracy, which in turn, contribute to the best timing strategy in CAT—with or without time constraints.

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