The following Guest article is an extract from the book Project Decisions: The Art and Science By authors Lev Virine and Michael Trumper, published by Management Concepts, Inc.© 2008. Reproduced with permission. Published here July 2008.

## Answers to Questions 5 to 10

5.   The correct answer is A (your forecast will lead to a 5% longer filming time than the official weather forecast). The moment of risk (when the snow falls) may significantly affect duration. See Chapter 17, "A Series of Unfortunate Events, or Event Chain Methodology."

6.   Whatever money you have already invested in MC Uglyface's career is a sunk cost. The high success rate of the ad campaign applies to other rappers, and there is evidence that more ad campaigns will not help MC Uglyface. We recommend answer C (give up with MC Uglyface and start promoting the rapper BadPosture). For more information about sunk cost, read Chapter 2, "'Gut Feel' vs. Decision Analysis: An Introduction to the Psychology of Project Decision-Making " and Chapter 20, "Adaptive Project Management."

7.   The correct answer is B (1%.) You need to multiply all probabilities: 0.1 (become celebrity) * 1 (married) * 1 (divorced) * 0.1 (choose lawyer) = 0.01. This question is related to the bias called "overestimating the probability of conjunctive events": people tend to choose much higher numbers. See Appendix B, "Heuristics and Biases in Project Management."

8.   The correct answer is B (love stories). This question is related to the co-variation assessment effect. People tend to pay more attention to high absolute values rather than relative indicators of success or failure. The relative chance that the screenplay will be produced is higher for love stories (11/2 = 5.5). See Chapter 14, "Choosing What Is Most Important: Sensitivity Analysis and Correlations."

9.   The correct answer is A (short descriptions such as "Bright hues mixed with pale tones" are more general and therefore more probable). The more conditions that you add to a description, the less likely it is that all of them will be met. This question is related to the representativeness heuristic and particularly to the conjunction fallacy. These are discussed in Chapter 2, "'Gut Feel' vs. Decision Analysis: An Introduction to the Psychology of Project Decision-Making."

10.   The correct answer is C (4 times). The probability always remains the same: 16% (25 trials * 16% = 4 times). This question is related to the gambler's fallacy. See Appendix B, Heuristics and Biases in Project Management."