Changes

Unfortunately, a number of psychological biases exist, many of which are described by Tversky and Kahneman,<ref name=Tversky_etal_1981>Tversky, A., and D. Kahneman, 1981, The framing of decisions and the psychology of choice: Science, v. 211, p. 453-458.</ref> that tend to produce inconsistencies whenever we estimate under uncertainty ([[:Image:Table_rose_time-value-of-money_1.jpg|Table 1]]). For the development geologist, three such biases are especially dangerous:

Unfortunately, a number of psychological biases exist, many of which are described by Tversky and Kahneman,<ref name=Tversky_etal_1981>Tversky, A., and D. Kahneman, 1981, The framing of decisions and the psychology of choice: Science, v. 211, p. 453-458.</ref> that tend to produce inconsistencies whenever we estimate under uncertainty ([[:Image:Table_rose_time-value-of-money_1.jpg|Table 1]]). For the development geologist, three such biases are especially dangerous:

# ''Overconfidence,'' which leads to excessively narrow ranges. People naturally tend to set predictive ranges that typically correspond to a confidence significantly lower than the ranges they think they are setting.<ref name=Capen_1976>Capen, E. C., 1976, The difficulty of assessing uncertainty: Journal of Petroleum Technology, v. 28, p. 843-850.</ref>

# ''Overconfidence,'' which leads to excessively narrow ranges. People naturally tend to set predictive ranges that typically correspond to a confidence significantly lower than the ranges they think they are setting.<ref name=Capen_1976>Capen, E. C., 1976, The difficulty of assessing uncertainty: Journal of Petroleum Technology, v. 28, p. 843-850.</ref>

# ''Conservatism,'' which leads to underestimates because professionals, fearing criticism, may feel it is worse to overestimate a project than to underestimate it.<ref name=Rose_1987>Rose, P. R., 1987, Dealing with risk and uncertainty in exploration--how can we improve?: AAPG Bulletin, v. 71, n. 1, p. 1-16.</ref>

# ''Conservatism,'' which leads to underestimates because professionals, fearing criticism, may feel it is worse to overestimate a project than to underestimate it.<ref name=Rose_1987>Rose, P. R., 1987, [http://archives.datapages.com/data/bulletns/1986-87/data/pg/0071/0001/0000/0001.htm Dealing with risk and uncertainty in exploration--how can we improve?]: AAPG Bulletin, v. 71, n. 1, p. 1-16.</ref>

# ''Motivation,'' which leads to overestimates because of career or economic self-interest on the part of the professional in "selling the deal."<ref name=Rose_1987 />

# ''Motivation,'' which leads to overestimates because of career or economic self-interest on the part of the professional in "selling the deal."<ref name=Rose_1987 />