The clicker is a useful, cheap tool that can help with timing of marking a correct behaviour when training your dog. It is completely optional as you can use verbal markers however many handlers prefer the precise, consistent marker than a clicker provides.
It works in the same way classic conditioning works. You may be aware of Pavlov and his dogs that learnt a rung bell meant dinner time. In a nutshell, he did the following:
Rang the bell and fed his dogs their meal. At this stage, the bell is just a noise that means nothing. He repeated this for several meals. During the process he noticed an increase in saliva production when the bell was rung. This saliva increase happened when there was no food prepared but the bell had been rung. He deduced that the dogs had learnt that the bell meant food was coming.
The clicker is simply a bell replacement (and you can indeed use any noise you like).
To teach the dog that the clicker means treats, simply click and treat 20 times (small, very tasty treats – treats pointers here). Let the dog chill for a couple of minutes and click again. Chances are good that your dog will look at you or the floor for the treats. Deliver the treats.
Now, you have a noise that tells the dog they are about to get good things. So using this we can teach new behaviours. For example, a simple sit:
Take a treat and hold it in your fingers near the tips. You are going to put your fingers right in front of your dogs nose (unless they are snappy – call me!) and lift your fingers just above the dogs head and towards their bum. Hopefully, they will plant their bum on the floor. As soon as you see bum to floor contact, click your clicker and give them the treats. Repeat x 5. For the next 5 say the word “sit” first and then lure the dog. Lure from further away – the aim is to either have no visual cue or have the visual cue of lifting your hand up to mean sit. Every time that bum touches the floor, click and reward.
The click is telling the dog at that exact instance “Yes! Perfect you delightful pupper, I am so proud! Here’s the cheese!”. They will soon start to offer the behaviour without even being asked – don’t reward that too much, we want them to be able to switch off easily too and just relax.