The question is in the title. I could not find an answer to this common question after searching on google nor on the StackExchange website, excepted this but the provided answer is not definite enough IMO.
The model is of the following form :
response ~ block + UnorderedCategoricalFactorOfInterest + error
It is not possible to test block:factor interaction because of no repetition in each block:factor cell, so I proceeded immediately to a type 2 test, in order to test main effects of block and factor.
It happens that block effect is not significant, and factor effect is highly significant.
From that point, what is best practice ? to keep it as is, or to re-fit the model without block ?