Wald Chi Square. The wald chi square test of the weibull distribution showed significant differences between adhesives p 001. Below the list of constraints we see the chi squared value generated by the wald test as well as the p value associated with a chi squared of 27 53 with two degrees of freedom.
The generalized wald chi square statistic is computed as where is an array of r 1 c 1 differences between the observed and expected weighted frequencies and estimates the variance of. Wald chi square statistisc estimate std error 2 the null hypothesis is tested using chi square distribution. Wald chi square test proc surveyfreq provides two wald chi square tests for independence of the row and column variables in a two way table.
Similarly the approximate confidence interval given α is given by 3 31 lˆβ t df α 2 l ni 1x iˆv 1 i xi 1 l.
Think of how a wald chi square is calculated estimate stderr 2. It looks like they have a large effect. I am not clear why we use chi square and not t statistics like in linear regression. The significance of variables is tested using wald chi square statistics and corresponding p value.
