In the context of creativity in design, much research has been done with an endeavor to discover the factors advocating creativity in design. Though, not much effort has been put in identifying of the factors disrupting creativity. One phenomenon that acts as an obstacle to creativity in design, or detracts from it, is the phenomenon of fixation. The term “design fixation” is often used interchangeably to refer to situations where designers limit their creative output because of an overreliance on features of preexisting designs, or more generally, an overreliance on a specific body of knowledge directly associated with a problem. It is understood as the inability to solve design problems by employing a typical or familiar method, ignoring new or better ones. In this research, an attempt has been made to investigate the factors that create fixation in design by examining how the previous knowledge of designers affects design. This way, a structure was presented to better understand the factors of fixation in the stages of the design process. Then it was explored what the differences and similarities in designers with different levels of expertise are. Finally, the formation of fixation in the design process stages, under the influence of the designers expertise level as an intervening variable, was explained. And so, the designers will be able to recognize the causes of their fixation and prevent fixation in design or at least reduce its amount. Also, design teachers, with awareness of these causes, will be able to guide students to stay away from this phenomenon. تفاصيل المقالة