In heuristic evaluation, the product is examined (after a short training session) by several experts. Each evaluator sits alone at the interface under examination and checks the product for compliance with ergonomic principles. The basis for this are personal knowledge and pre-formulated ergonomic principles, so-called heuristics. The results are then compiled in a list. Experts then assess the recorded problems on a scale according to their severity and thus according to how urgently they should be corrected.