I have three continuous variables one of which I have hypothesised to be a moderator. In the overall regression model there is no significant result for the product of the IV and predicted moderator, R2 change = .00, F change (1, 118) = 0.46, p >.05. That is, there is no overall moderating effect. However, when I use the PROCESS plug in to test for possible combined effects at different levels of the hypothesized moderator, using both the pick a point and Johnson Neyman technique a moderator effect can be seen at certain levels of the moderator.

My question:

1) Is it justifiable to proceed to test for combined effects at different levels of the moderator once you have shown there is no overall moderator effect?

2) Are there published papers which explain this approach?

I have searched the forum and noted a few other people have posted similar questions but to date there have not been any suggestions as to the best way to proceed.

Any advice would be appreciated.