尝试错误法（trial and error）是一种用来解决问题、获取知识的常见方法。此种方法可以视为简易解决问题的方法中的一种，与使用洞察力和理论推导的方法正好相反。

在试错的过程中，选择一个可能的解法应用在待解问题上，经过验证后如果失败，选择另一个可能的解法再接着尝试下去。整个过程在其中一个尝试解法产生出正确结果时结束。

Trial and error is a fundamental method of solving problems. It is characterised by repeated, varied attempts which are continued until success, or until the agent stops trying.

According to W.H. Thorpe, the term was devised by C. Lloyd Morgan after trying out similar phrases "trial and failure" and "trial and practice". Under Morgan's Canon, animal behaviour should be explained in the simplest possible way. Where behaviour seems to imply higher mental processes, it might be explained by trial-and-error learning. An example is the skillful way in which his terrier Tony opened the garden gate, easily misunderstood as an insightful act by someone seeing the final behaviour. Lloyd Morgan, however, had watched and recorded the series of approximations by which the dog had gradually learned the response, and could demonstrate that no insight was required to explain it.