These investigators further found that age, years of management experience, and years in current position were unrelated to tacit knowledge. The lack of a correlation of tacit knowledge with years of management experience suggests that it is not simply experience that matters, but perhaps what a manager learns from experience. A manager's years with current company was negatively related to tacit knowledge (r = -.29, p < .01), perhaps indicating that ineffective managers stayed around longer than effective managers. The number of companies that a manager had worked for was positively correlated with tacit-knowledge scores (r = .35, p < .001). Years of higher education was highly related to tacit knowledge (r = .37, p < .001), as was self-reported school performance (r = .26, p < .01). Similarly, college quality was related to tacit knowledge (r = .34, p < .01). These results in conjunction with the independence of tacit knowledge and overall cognitive ability suggest that tacit knowledge overlaps with the portion of these measures that are not predicted by overall cognitive ability.

Williams and Sternberg also performed hierarchical regression analyses to examine whether tacit knowledge contained independent information related to success that was distinct from that provided by background and experience. The pattern of results was similar across analyses. In the regression analysis predicting maximum compensation, the first variable entered in the regression equation was years of education, accounting for 19% of the variance (p < .001). The second variable entered was years of management experience, accounting for an additional 13% of the variance (p < .001). The third and final variable entered was tacit knowledge, accounting for an additional 4% of the variance (p = .04), and raised the total explained variance to 36%. In the regression predicting maximum compensation controlling for age, the number of years of education was entered into the equation first, accounting for 27% of the variance (p < .001). And second, tacit knowledge was entered, explaining an additional 5% of the variance (p = .03). This final regression demonstrates the value of tacit knowledge to managers who are relatively successful for their age.

5.7 College students

Williams and Sternberg (cited in Sternberg et al., 1993) studied the tacit knowledge of college students. They asked 50 Yale undergraduates the question: "What does it take to succeed at Yale that you don't learn from textbooks?" and used the responses to develop a tacit-knowledge inventory for college students. The inventory consisted of 14 situations and asked respondents to rate the quality of several options on a 1 to 9 scale. For example, one question described a student enrolled in a large introductory lecture course. The class requirements included three exams and a final. Participants were asked to rate how characteristic of their behavior it was to spend time doing various activities, such as (1) attending class regularly, (2) attending optional weekly review sections with a teaching fellow, (3) reading assigned text chapters thoroughly, (4) taking comprehensive class notes, and (5) speaking with the professor after class and during office hours.

The criteria were two indices: an academic index and an adjustment index. The academic index was a composite of high school GPA, college GPA, SAT scores, and CEEB achievement test scores. The adjustment index was a composite of a measure of happiness in college, a measure of self-perceived success in college, a measure of self-perceived success in using tacit knowledge, a measure of the extent of benefit each participant had experienced from acquiring tacit knowledge, and a measure of the rated closeness of the college to the participant's ideal college.