The efficiency and popularity of computer-aided design (CAD) packages have been continually improving over the past couple of decades. Most of the graduating engineers are proficient in their use and prefer using CAD models instead of simple freehand sketches to communicate their ideas. While these CAD models can enable better visualization of the initial designs, some of the prior studies highlight a few disadvantages of using those for the initial stages of engineering design. Some of the critical concerns raised by observational studies include constrained thinking and design fixation while using CAD models. Motivated by the scarcity of empirical evidence regarding the use of CAD models in engineering design practice and education, this paper reports a study conducted in a freshman design classroom where students are instructed to generate a creative idea using CAD models as their medium of representation. One group of students are given a simple example while another is given one with more detailed features. The presence of example features in the designs they generated is compared against that of a control group. The results show that while generating ideas in a CAD package, the students fixate on example designs and this fixation is more significant when the example is more detailed. Unlike physical prototypes, CAD models do not offer immediate feedback on the designs which might prompt students to keep their ideas with fixated features.