Three experimental studies with high school students and university students as subjects were carried out in order to investigate the effects of different conditions on the performance of creative tasks. Study 1 investigated the effects of working individually (Single-work group) or in a Group (Group-work group) upon fluency, flexibility, and originality. It was found that although Group-work produced better results on the different measures of creativity, the total fluency score was higher for the Single-work group. Study 2 investigated whether or not two techniques for enhancing creativity, random word input and provocation, produced effects upon creative performance. It was shown that fluency after the manipulation was lower for the random word and provocation conditions, but not for the control condition. In Study 3, which differences in the creative process between subjects working during a period of three days under varying conditions, namely working as an individual versus working in a group (Assemblage condition) and working under control condition versus working with random word input (Technique condition). Group-work showed higher fluency and originality, although the Single-work group showed a greater mean value on fluency. Group-work produced also higher scores on thought change and incubation at all levels of the creative process, whereas the Single-work group produced higher scores on assertion for the original product and illumination on the final product. These results suggest that the Single-work group reached further in the creative process than the Group-work group. The participants in the random word condition showed a lower rate of flexibility than the participants in the control condition did, but also a higher level of thought change during the middle phase of the experiment.