What do you do when you predict a successful repetition in a shaping session and then, just as you are pushing down on the clicker, something happens? The anticipated behavior is not successfully completed? Uh oh.  Your brain told you not to do it but your finger didn't listen!  Or at least, your finger didn't listen fast enough.  So now you've got a half click - holding down the metal thing (what's that called?) and trying to decide how to get out of it.  Which, of course, you can't. Your finger has to come up eventually and...your dog is waiting you know. In general, if I promise a cookie or toy or whatever, then I give it since a click sound is followed by a reinforcer in my training repertoire.  But I don't give a cookie for a half click.  I know many people who do - a promise is a promise and they fill it.  Not me - I just try really really really hard not to do that again.   Of course, the dog heard that sound and expects a cookie, so you need to do something.  Me? I'm probably laughing - screwed that up big time and now I'm stuck with my thumb in limbo land. What I do is let up the metal bit, cue another easy behavior, hand over a reinforcer and try to do a bit better next time. Now at this point in my training journey I usually do a mouth click and half clicks aren't even possible - I clicked.  It's done.  But screw ups continue and I still don't reinforce if I screw it up.  I ask for something else and reinforce that. When you half click - what do you do?  Feed anyway, laugh it off and create success some other way, or just continue on as if nothing happened?