HART

Marker

A short signal (word or click) given exactly when the dog performs the correct behaviour. It tells the dog: "that was it, the Reward is coming".

The Marker is a "bridge" between the dog's behaviour and the Reward. Without it, the Reward arrives too late — the dog doesn't know what exactly they were rewarded for.

The most common forms in HART:

Order: dog performs the behaviour → Marker → Reward. A Marker without a Reward (or with a long delay) quickly loses its value. A Reward without a Marker "blurs" — the dog gets paid, but doesn't know what for.