Have an idea?

Visit Sawtooth Software Feedback to share your ideas on how we can improve our products.

Calculating p value from t ratio

What is the correct way of obtaining the p value of the t ratio in the multivariate logit regression analysis of a CBC exercise? I have 5 attributes, four of which have 2 levels and one of which has 3 levels.
asked May 25, 2018 by anonymous

1 Answer

0 votes
You compute it just like any other t-statistic with n-1 degrees of freedom.  Since most of our models will have n>30, the relevant t distribution will effectively be the normal curve  and we can use the Z statistic, where values in excess of |1.96| are significant at p=.05.

Alternatively you can look your t-ratio up on a standard t-test table from a reference book or you can calculate it in r or Excel or whatever - in Excel the formula is =T.DIST.2T(t,df)
answered May 27, 2018 by Keith Chrzan Platinum Sawtooth Software, Inc. (105,750 points)
how to calculate p-value for t-ratios.
...