Documentation is used here to mean hard copy, online documents, online help, quick start guides, and other written instructional information. The need for documentation is often an afterthought when designing products. Product development engineers are so enmeshed in creating the product that they feel its use is intuitive or self-evident. This assumption is usually not the case. In many respects, documentation compensates for the lack of intuition. It permits understanding the product and provides a quick source for looking up specific details that are not immediately obvious to the user.