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Originally Posted by Chris Noble 
Alex is already suggesting that the dog starts "signalling" within a few minutes of the owner (or other person) starting the return journey. If Alex's results are to be believed then there isn't any noise to speak of. The dog spends zero time "signalling" in the main period. If the dog really does this repeatedly then what are you worried about?
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I would be worried about the possibility of including too much noise in the analysis if a 'signalling' method of analysis is used, as you've described. If the dog performs as well as the taped examples then there doesn't seem to be much noise, but why adopt a design that allows for it? If you adopt the methods you've suggested then you assume the phenomena works in a particular way and run the risk of introducing noise.
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What statistical test are you going to use? What would be a statistically significant result?
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I would compare the proportion-of-total-waiting-time means for the main and return periods, probably using a non-parametric method.
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Your criteria would give the same value if the dog started signalling at the start of a 60 minute return journey as if it started signalling in the last 10 minutes.
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Yes, but either way, the result would be positive and you don't have deliberate over whether to exclude 'false starts' from the analysis due to some distraction or other. So, I'm not assuming a temporal relationship between the start of the return journey and the start of the waiting behaviour. There may well be such a relationship, but there might not.