Understanding the attention of a salient distracting feature in a friction force question

Physics problems both found in classroom settings and encountered in real world scenarios can often include extraneous or unnecessary information. If the information is salient, it can control attention potentially driving the problem solver towards an incorrect solution. Developing a capacity to ignore such salient distracting features or override models or solutions derived from them is thus a useful skill for a physics student. To understand the role of such features in physics questions, we have tasked undergraduate students with solving one of two versions of a Newton's laws question in the context of friction. In both versions of the question, students are given information about the coefficient of friction. In one version of the question, a numerical value is given, whereas in the other, students are only given a variable. We compare student performance on each of these questions, explaining the findings through the lens of dual-process theories of reasoning.