Design fixation experiments often require participants to solve a design problem whilst being exposed to an example solution and instructions for how to treat that example. However, little is known about the influence of such instructions, leading to difficulties in interpreting results and understanding how the introduction of examples affects idea generation. In our experiment, participants were all provided with the same design problem and example solution, but were presented with different instructions, ranging from strongly encouraging copying the example to strongly discouraging copying. Analyses of participants’ work indicated that only the instructions encouraging copying had an effect. When encouraged to copy, participants tended to only copy the structural features of the example rather than the underlying concept. By contrast, the number of features copied was not reduced when participants were discouraged from copying. These findings suggest that there are subtle interactions between instructions and stimuli that influence design fixation.