Adriaan de Groot

In 1946 he wrote his thesis Het denken van den schaker,[2] which in 1965 was translated into English and published as Thought and choice in chess.

They investigate the cognitive requirements and the thought processes involved in moving a chess piece.

The participants were usually required to solve a given chess problem correctly under the supervision of an experimenter and represent their thought-processes vocally so that they could be recorded.

De Groot found that much of what is important in choosing a move occurs during the first few seconds of exposure to a new position.

Finally, in the fourth stage, the 'proof phase', saw the subject confirming with him/herself that the results of the investigation were valid.