If someone were to say to you “say alligator” and you responded with “crocodile,” this would be an example of thematic control because there would be no point-to-point correspondence between the stimulus and the response. For that matter, you could say “doorknob” and that would be thematic control, too.
When a controlling variable evokes a response and has the following features:
There is NO point-to-point correspondence between the controlling variable and the response