I decided to focus my semantic differential on grain mills. I will provide participants with several images of different mills, and ask them to say whether on a continuum the products sit. Potential word pairs are: trendy-dated; fun-dull; stressful-relaxing; unsatisfying-satisfying; difficult-easy; dependable-unreliable; efficient-inefficient; high-quality-low-quality; meaningful-meaningless.
Rik completed my differential with one image, and pointed out that some of the word pairs were more experience-based, and would be easier to answer had he actually used the product in the image. These word pairs were efficient-inefficient, high-quality-low-quality, and meaningful-meaningless. Maybe I could replace these pairs with other words to get better results.