At what stage do you introduce the detection dog to the concept that sometimes (most times) he is not going to find something in that room. Have ordered Eds DVD.

My dd an English Springer Mix is fairly good at finding the placed scent. Usually under 1 minute in a small room he will find. He is getting the hang of the sit to indicate and will 60% of the time do it automatically, the rest of the time I remind him before throwing his ball and giving him lots of fuss.

Today on 2nd search I led him into a 'clean room' and allowed him 90 seconds to search - the last 40 seconds or so, his searching became a little frantic. After 90 seconds I called him out of the room and gently (physically and verbally) praised him. I then led him back to the vehicle.
After 3 regular searches I then did this again but when I called him out this time he gave a false indication. I turned my back and walked off, he followed and then I gave him mild praise.

Was this the right thing to do? Or am I pushing him too hard? he's had about 2-3 hours training daily (split into several sessions) for 5 weeks with the occasional day off.

Each search has distance and time when something is not found. Each is increased as the dog gains proficieny. Meaning the dog can perform at a level, consistently. When a dog gives a response (false) experience has shown me, more often than not, ignoring that behavior is the best bet. Certainly we don't reinforce it, corrections, whether physical/verbal etc, also call attention to the behavior. Totally ignoring the behavior means the dog recieved no attention whatever. In situations like that, I merely repeat the "find it" command and continue searching. Odor/response, time and distance, the keys good search behavior.

DFrost

My Springer on rare occasions gives a false indication if I am on top of him during a search. If its a false indication when I move away he will carry on searching so you did the right thing be ignoring him I would say.