What did Tolman mean by vicarious trial and error?
Indeed Tolman described different intervening variables in a logical manner, but he focused on the relationship of a cognitive map that was used to predict the several numbers of hypotheses. His mentalistic approach was also reasonable to explain the different kind of hypothesis in a pre-defined manner.
Tolman explains the concept behind the learning of a rat to solve a maze. He described that when a rat is first placed in the box of a T-maze, its experience level is almost new. As the rat runs the maze, it turns right and left at the median point. At some intermediate point, the animal identifies a hypothesis that tells that turning one way finding for food and turning another way does not find something.
So, by formulating hypothesis, the animal adjusts at the critical level of point that begins to pondering the goal of alternatives approach. Thus, Tolman referred to this type of crucial pondering that are collectively known as vicarious trial and error. In this, one behaves smartly in a trial and error manner by stimulating the animal to busy in a state of mental trial and error. It combines both the aspects of expectancy and belief.