SUMMARY A series of experiments were conducted to examine the purported role of fixation in the solution of several insight problems, such as the nine-dot and triangle problems. It has been commonly accepted in psychology that such problems are difficult because subjects are fixated on unwarranted assumptions concerning how the problems are to be solved. In the present studies, subjects were disabused of these allegedly fixating assumptions in order to see whether quick and direct solution of the problem would then follow. For example, subjects working on the nine-dot problem were told that the problem could be solved only by extending their solution lines outside the boundaries of the square formed by the dots, and subjects working on the triangle problem were told to work in three dimensions. The basic finding was that removing the alleged fixation did not result in sudden and direct solution of the problems, indicating that fixation was not a very important factor in making these problems difficult. It was also found that significant facilitation of solution in these problems could be brought about only by giving subjects relatively detailed information about the solution. It was concluded that the terms fixation and insight are not useful in describing the processes involved in the solution of these problems, and the role of problem-specific knowledge in the solution of insight problems was emphasized. The relationship between the present findings and other recent work on problem solving is also discussed.