THE MARKOV CHAIN AS NULL HYPOTHESIS IN A DEVELOPMENT SURVEY1

Development criteria observed as time series on nominal variables pose a problem for research design. Markov chains are attractive in the first instance because they can handle such multivariate multinomial data sets, with results that are described and demonstrated on Career Development Study data. The power of the formal probability model is purchased at the expense of assumptions that may be unrealistic. It is argued and demonstrated that where the Markov chain theory for the data breaks down is precisely where the most interesting part of the message contained in the data resides. The Markov chain is shown to be a better null hypothesis against which to array the psychometric or other prediction model than is the usually employed random walk. A new prediction system that combines information from the Markov chain with the psychometric predictors is described and operated.     

Book Reviews

Book Reviews in This Article: Mastering Statistics Second Edition. From Cooperation to Coordination. Implications of New Technology for the School Curriculum.     

TECHNICAL GUIDELINES FOR ASSESSING COMPUTERIZED ADAPTIVE TESTS

Guidelines are proposed for evaluating a computerized adaptive test. Topics include dimensionality, measurement error, validity, estimation of item parameters, item pool characteristics and human factors. Equating CAT and conventional tests is considered and matters of equity are addressed.