Abstract
People often believe that they have a good understanding of how devices work (e.g., how a ballpoint pen works), despite having poor knowledge of their internal mechanics. We hypothesized that this bias occurs in part because people conflate mechanistic understanding with functional understanding of how devices work (e.g., how to operate a ballpoint pen). In two experiments, we found that increasing the salience of mechanistic information led to lower judgments of understanding for how devices work. In Experiment 1, we did this by showing participants either the internal parts of a device or an external, whole-object view of that same device. Those who saw the internal parts rated their understanding as less than those who saw a whole-object view. In Experiment 2, we removed the pictures and instead tested participants (without feedback) on their mechanistic or functional knowledge using true-or-false questions. Those who were tested on mechanistic knowledge rated their understanding of devices as less than those who were tested on functional knowledge.