Professor Tysseland's paper, “Further Tests of the Validity of the Industry Approach to Investment Analysis,” calls into question the validity of the industry approach to investment analysis. His examination of inter- and intra-industry investment results through time leads him to conclude that “the lack of homogeneity within industries is great and industry consistency in performance over time is unimpressive.” Furthermore, he states that a prospective investor who chooses investments based on past industry performance records is on tenuous grounds and that “the usual types of industry data, analyses and forecasts generally made available by financial magazines, brokerage houses, and investment services, may be of doubtful value.”