First, there is information that is available but too voluminous to collect or, if collected, to comprehend. Second, there is information that is simply not available. Available but unusable information includes the particular preferences of each of the people living in the urban area. The Portland area, for example, has over a million residents and well over 400,000 families. Each of them has different tastes and desires, and while they can be measured to some degree, no agency has enough money to poll every single person in its jurisdiction.
Unavailable information includes data about the future.
All of these questions and many more are inherently unknowable. The Confusion of Ideals with Facts Confronted with a lack of information and uncertainty about the future, planners substitute their ideals for facts, often without being consciously aware of it. Everyone does this to some degree, but for some reason the planning profession seems to be extraordinarily susceptible to this. There are endless examples of such confusion of ideals with facts. In Forest Service planning, we saw almost every national forest presume that timber prices were 50 to 200 percent greater than timber purchaser were actually paying for timber.