In following with the topic of building experience, gap years, etc., for those of you who have applied multiple times to PhD programs, how significantly (if at all) do you change your SOP and/or writing sample? I will most likely be applying again to programs next year, and I am unsure of which parts of my application to change and which to keep the same. It's not that my research interests change, but I'm worried that submitting the same application materials year after year will just produce the same results.