I would be most grateful if you could advise me on the availability of pre-existing code that will allow me to run the model assumptions for ANCOVA in addition to running the ANCOVA process itself. I normally use SPSS for ANCOVA but I would like to run an ANCOVA and corresponding model assumptions testing over multiple random samples taken from a single sample. I had initially assumed that the bootstrap approach may be correct for this but I should clarify that the end I have in mind is not to obtain a summary result from bootstrapping. I simply wish to compare results from running an ANCOVA and corresponding model assumptions testing across multiple random samples of a fixed size. Therefore, I am also interested to know if a better approach would be to generate the random samples first, save them in separate columns of a spreadsheet and then run the ANCOVA and model assumptions testing across each column separately. I would welcome advice on the most efficient approach to take.

Many thanks!