01630nas a2200157   4500008003900000245010100039210006900140300001200209490000700221520111200228100001501340700001601355700001901371700002501390856005701415       2013                          d00aA Semiparametric Model for Jointly Analyzing Response Times and Accuracy in Computerized Testing0 aSemiparametric Model for Jointly Analyzing Response Times and Ac  a381-4170 v383 a<p>
	The item response times (RTs) collected from computerized testing represent an underutilized type of information about items and examinees. In addition to knowing the examinees&rsquo; responses to each item, we can investigate the amount of time examinees spend on each item. Current models for RTs mainly focus on parametric models, which have the advantage of conciseness, but may suffer from reduced flexibility to fit real data. We propose a semiparametric approach, specifically, the Cox proportional hazards model with a latent speed covariate to model the RTs, embedded within the hierarchical framework proposed by van der Linden to model the RTs and response accuracy simultaneously. This semiparametric approach combines the flexibility of nonparametric modeling and the brevity and interpretability of the parametric modeling. A Markov chain Monte Carlo method for parameter estimation is given and may be used with sparse data obtained by computerized adaptive testing. Both simulation studies and real data analysis are carried out to demonstrate the applicability of the new model.</p>
1 aWang, Chun1 aFan, Zhewen1 aChang, Hua-Hua1 aDouglas, Jeffrey, A.  uhttp://jeb.sagepub.com/cgi/content/abstract/38/4/381