In our work on hoarding, we’ve found that people have very different ideas about what it means to have a cluttered home. For some, a small pile of things in the corner of an otherwise well-ordered room constitutes serious clutter. For others, only when the narrow pathways make it hard to get through a room does the clutter register. To make sure we get an accurate sense of a clutter problem, we created a series of pictures of rooms in various stages of clutter – from completely clutter-free to very severely cluttered.