A training approach in which the criterion for reinforcement is set so the animal almost always succeeds and rarely makes mistakes.

Errorless learning works by raising criteria in very small steps, often using shaping with successive approximation, so the animal builds skill without accumulating reinforcement history for incorrect responses. Each step is set such that the animal can succeed if they make a reasonable attempt, and the criterion is raised only when the current step is reliably mastered.

The approach is particularly useful in clinical work with fearful or anxious animals across species, and is increasingly used in horse work and in dog sports training. Animals working through fear or anxiety benefit substantially from training that does not require them to fail repeatedly; each failure is an opportunity for the existing negative associations to be reinforced rather than resolved.

The technique has its origins in research on learning in laboratory contexts but has been substantially developed in applied animal behaviour work, particularly through the work of researchers and practitioners working on phobias and anxiety in companion animals. The basic principle that minimising errors during learning produces better welfare and better learning outcomes has been demonstrated across species.

Errorless learning is also useful for any training context where errors carry significant cost. Training a dog to leave dangerous items alone, training a horse to load onto a float without ever associating the float with stress, training a service animal to perform specific tasks reliably, all benefit from approaches that minimise opportunities for the wrong response to be learned.

The trade-off of errorless learning is that it can be slower in the short term than approaches that accept more errors. The advantage is that the learning that does occur tends to be more durable, more flexible, and less encumbered by competing reinforcement history. In most applied contexts, the slower initial pace is more than compensated by better long-term outcomes.

The approach can be combined with conventional shaping approaches in practice. Many trainers use errorless learning principles for difficult phases of training while accepting more variation and errors in easier phases.