Designers commonly interact with products in the early phases of design in order to understand the solution space and gain inspiration for new designs. Although designer-product interaction methods such as visual inspection and product dissection are recognized as a pivotal component of the engineering design process, little data is available on how these practices affect idea generation or when these activities are most useful for inspiring creative thought. Therefore, the current study was developed to understand the impact of these activities on creative idea generation. During our controlled study, fifty-nine undergraduate engineering students were instructed to either visually inspect or physically dissect an example milk frother and then generate ideas for a new, innovative design. These concepts were then evaluated for their novelty, variety, quality and quantity. Our analysis (ANOVA) revealed that participants who physically dissected the example frother produced ideas that were more novel but of lower quality than those that simply inspected the frother. Our results provide insights on the impact of designer-product interactions on creativity and we use these findings to develop recommendations for the use and alterations of these practices for improving creativity in engineering design.