Homogeneity Reliability Indicator Is A Comparative Study

In psychological and educational measurement,Reliability is an important index of estimating test's quality. The index of scale reliability most often used in the behabioural sceences appears to be homogeneity reliability.the methods of estimating homogeneity reliability mostly is Cronbach's coefficient alpha, coefficient β , coefficient γ , coefficient ζ and coefficient ρ .wo are interested in that in what extent can these index can response true reliability coefficent in hell and which one is better.This study first gives a general introduction of the topics based on CTT, which cover the definion of reliabiliy and homogeneity reliability.the methods and models of estimating homogeneity reliability index . It follows with a date simulation research which change three independent variable:interviewees, item and t -equivalent, the simulation method described is applied to 27 simulated sets of multinomial data which are generated using LISREL 8.50 according to the prespecified model and compare the capability of responsing true reliability coefficent among Cronbach's coefficient alpha, coefficient β , coefficient γ , coefficient ζ and coefficient ρ .in addition, using pxi random effect model with one facet based on GT,which each facet has three condition validates simulation research prove the date simulation research.This paper indicate Cronbach's coefficient alpha change regularly,it's very sensitive to T -equivalent suppose; coefficient β , coefficient γ, coefficient ζ are similar in estimating true reliability coefficient of the scale,have not visible disciplinarian,these index is better than Cronbach's coefficient alpha; coefficient ρ is a very good estimation of homogeneity reliability which can response reliability under all the 27 simulated sets, homogeneity reliability is not influenced by one factor singly but changed by multi-factors.The results of this paper supplies an effective support for paychological and educational research .The research also supplies the valuable theoretic basis for accurately using index of homogeneity reliability.