Forsyth in 2008, this effect was tested to determine if it could be used to reduce the planning fallacy. In three experiments, the segmentation effect was shown to be influential. However, the segmentation effect demands a great deal of cognitive resources and is not very feasible to use in everyday situations. Implementation intentions Implementation intentions are concrete plans that accurately show how, when, and where one will act. It has been shown through various experiments that implementation intentions help people become more aware of the overall task and see all possible outcomes. Initially, this actually causes predictions to become even more optimistic. However, it is believed that forming implementation intentions "explicitly recruits willpower" by having the person commit themselves to the completion of the task. Those that had formed implementation intentions during the experiments began work on the task sooner, experienced fewer interruptions, and later predictions had reduced optimistic bias than those who had not. It was also found that the reduction in optimistic bias was mediated by the reduction in interruptions. Reference class forecasting Reference class forecasting predicts the outcome of a planned action based on actual outcomes in a reference class of similar actions to that being forecast. Real-world examples The Sydney Opera House was expected to be completed in 1963. A scaled-down version opened in 1973, a decade later. The original cost was estimated at $7 million, but its delayed completion led to a cost of $102 million. The Eurofighter Typhoon defense project took six years longer than expected, with an overrun cost of 8 billion euros. The Big Dig which undergrounded the Boston Central Artery was completed seven years later than planned, for $8.08 billion on a budget of $2.8 billion (in 1988 dollars). The Denver International Airport opened sixteen months later than scheduled, with a total cost of $4.8 billion, over $2 billion more than expected. The Berlin Brandenburg Airport is another egregious case. After 15 years of planning, construction began in 2006, with the opening planned for October 2011. There were numerous delays. It was finally opened on October 31, 2020. The original budget was €2.83 billion; current projections are close to €10.0 billion. California High-Speed Rail is still under construction, with tens of billions of dollars in overruns expected, and connections to major cities postponed until after completion of the rural segment. See also References Further reading Lev Virine and Michael Trumper. Project