Quote:
Originally Posted by Chris Noble  If the dog simply waits ten minutes and then starts "signalling" and remains there then it wil spend a higher proportion of time at the "waiting spot" when the owner is returning than when the owner isn't returning. This will happen with perfect controls and randomisation. |
That's a good point. There surely must be a way to compensate for that, though? (Without using post hoc analyses, of course.)
How about this?
You separate the trial into ten minute intervals, then after the trial is complete, you take out the period in which the dog spends the most time at the window, and use the starting time of this period as the measure of success. If the start of the longest waiting period corresponds to the start of the return of the owner, the trial is a success.
It will look like this then:
Dog waiting
____________ _ _ _ _ _______________________
|10min|10min|10min|10min|10min|10min|10min|10min|
Owner returning
__________________________________________
|10min|10min|10min|10min|10min|10min|10min|10min|
Success!
Dog waiting
_________ _ _ _ _ _____________________________
|10min|10min|10min|10min|10min|10min|10min|10min|
Owner returning
_____________________________________________
|10min|10min|10min|10min|10min|10min|10min|10min|
Failure!
Of course you will have to randomize the return times to make sure the dog doesn't succeed just by starting waiting at the same time every trial.