How is GLM used?
The GLM generalizes linear regression by allowing the linear model to be related to the response variable via a link function and by allowing the magnitude of the variance of each measurement to be a function of its predicted value.
Is t-test a GLM?
A t-test is a test. A GLM is a model. Hence, they are not even the same type of thing. You can perform a test without assuming anything whatsoever about the response; it’s just that the test may-or-may-not have the expected properties.
What is the difference between t-test and Mann Whitney test?
Unlike the independent-samples t-test, the Mann-Whitney U test allows you to draw different conclusions about your data depending on the assumptions you make about your data’s distribution. These different conclusions hinge on the shape of the distributions of your data, which we explain more about later.
Should I use t-test or regression?
A T-test is used to compare the means of two different sets of observed data and to find to what extent such difference is ‘by chance’. Linear Regression is used to find the relationship between one dependent or outcome variable and one or more independent or predictor variables.
Should I use Mann Whitney or t-test?
If your data is following non-normal distribution, then you must go for Mann whitney U test instead of independent t test. It depends on what kind of hypothesis you want to test. If you want to test the mean difference, then use the t-test; if you want to test stochastic equivalence, then use the U-test.
Is the Wilcoxon-Mann-Whitney test a special case?
The Wilcoxon-Mann-Whitney test is a special case of the proportional odds ordinal logistic model so you could say there is no need to turn the model around to use logistic regression. But the fundamental issue in choosing the model is to determine which variables make sense to adjust for.
Can a GLM be used as a pairwise comparison?
The GLM may tolerate some heteroscedasticity, but if it is very large you may be working with a very large type I error rate. In option a) you may use Mann-Whitney for pairwise comparisons combined with the method of Bonferroni or Sidak that use an adjusted alpha for the posteriori comparisons.
Is there a general rule for the GLM?
There is not a general rule for a situation like you describe. The GLM may tolerate some heteroscedasticity, but if it is very large you may be working with a very large type I error rate.
Why is the Mann Whitney significant when medians are equal?
The results suggest that there is a statistically significant difference between the underlying distributions of the write scores of males and the write scores of females (z = -3.329, p = 0.0009). FAQ: Why is the Mann-Whitney significant when the medians are equal?