If it is widely understood that one of the principal causes of IS failures is a lack of user involvement, and if this factor continues to be a problem after 30+

years of experience, does this mean that the problem cannot be solved? For example, everyone knows that you can maximize your gains by buying stocks at their annual low price and selling them at their annual high price, but doing so is very difficult. Is it equally true that although everyone knows that users should be involved in requirements specification, and that requirements should be complete, it just cannot be done? Why or why not?