ABSTRACT
Verbal reports have been used as a data collection tool in psychology since the early twentieth century. The earliest studies in this vein (e.g. Ewert & Lambert, 1932; Katona, 1940) investigated the effects of experimenter-provided verbalizations on participants’ task performance. In these studies, the experimenter would first identify a series of principles necessary for successful completion of the problem-solving task and would then state those essential principles to one group of participants, hypothesizing that this verbalization would improve participants’ performance as compared to a control group of participants who did not receive any such verbal guidance. By the 1950s, in large part as a result of the ideological shift away from behaviorism, psychologists began re-directing the focus of experimentation to participants’ own cognitive processes. It was at this point that researchers began to investigate the effects of participants’ own verbalizations on task performance (e.g. Brunk et al., 1958; Gagné & Smith, 1962; Hafner, 1957; Marks, 1951).
