Through Monte Carlo procedures, three different techniques for estimating the parameter theta (proportion of the "shocks" remaining in the system) in the Integrated Moving Average (0,1,1) time-series model are compared in terms of (1) the accuracy of the estimates, (2) the independence of the estimates from the true value of theta, and…

This paper develops and applies three nonparametric comparisons of the shapes of two item characteristic surfaces: (1) proportional latent odds; (2) uniform relative difficulty; and (3) item sensitivity. A method is presented for comparing the relative shapes of two item characteristic curves in two examinee populations who were administered an…

The use of item response theory models for analyzing the results of judgmental standard setting studies (the Angoff technique) for establishing minimum pass levels is discussed. A comparison of three methods indicates the traditional approach may not be best. A procedure based on generalizability theory is suggested. (GDC)

Describes the two basic approaches to the calculation of term discrimination values for automatic indexing. The results of an experiment that investigated the differences between algorithms of these two approaches in terms of their impact on the discrimination value model are reported and discussed. (13 references) (Author/CLB)

A Bradley-Terry type model for paired comparisons is considered which allows for individual parameters and corresponding parameters for the choice-alternatives. Model is applied to data from a Danish investigation of blue collar attitudes towards alternative social gains. Model is compared to one suggested by Schonemann and Wang. (RC)

This paper describes two statistics (chi square and Kendall's S) which may be used to test hypotheses about the association between two variables when observations are cross-classified in a contingency table. (CK)

Twelve variance-analytical and nonparametrical coefficients of reliability for rating scales designed for rating persons were compared to each other theoretically and empirically. Preference for two coefficients was established. The intraclass correlation coefficient appeared to be useful for the estimation of reliability as well. (Author/RL)

Using several data sets, the relative performance of the beta binomial model and two more general strong true score models in estimating several indices of classification consistency is examined. It appears that the beta binomial model can provide inadequate fits to raw score distributions compared to more general models. (TJH)

Recently, C. E. McCulloch (1987) suggested a modification of the Morgan-Pitman test for comparing the variances of two dependent groups. This paper demonstrates that there are situations where the procedure is not robust. A subsample approach, similar to the Box-Scheffe test, and the Sandvik-Olsson procedure are also assessed. (TJH)

The robustness of the likelihood ratio difference statistic to the violation of a regularity condition when used to assess differences in fit provided by pairs of latent class models was investigated. Recommendations are made regarding the use of the statistic under violation of the regularity condition. (SLD)

Two observed-score methods that assume equally reliable congeneric tests were compared for the external anchor test equating model. Each derivation was compared to existing test equating methods based on different assumptions. Using samples of Australian secondary school students (N=about 6,000), the methods were compared empirically with existing…

Multivariate and univariate analysis of variance methods (MANOVA and ANOVA, respectively) are compared for their relative value in educational research. The favoritism shown multivariate techniques is questioned. Criteria for the selection of the appropriate technique are outlined. The relationships among research hypotheses, statistical…

A formula that is simpler to calculate than the Kappa statistic of J. Cohen is presented for the situation where each subject in an experiment is rated on a nominal scale by two or more judges. Equivalence with Pearson's chi-square statistic in this situation is demonstrated. (SLD)

Presents two new algorithms for performing arithmetic coding without employing multiplication and discusses their implementation requirements. The first algorithm, suitable for an alphabet of arbitrary size, reduces the worst case excess length to under 0.8%. The second algorithm, suitable only for alphabets of less than 12 symbols, allows even…

Presents an inference algorithm that produces a weighted finite automata (WFA), in particular, the grayness functions of graytone images. Image-data compression results based on the new inference algorithm produces a WFA with a relatively small number of edges. Image-data compression results alone and in combination with wavelets are discussed.…