Actually, a written observation is not called a hypothesis. A hypothesis is a testable explanation or prediction based on prior knowledge or observations. However, a written observation is typically referred to as a "note" or a "written record." It is a detailed account of what one has observed or experienced. These written observations are often used in scientific experiments, field studies, or personal observations to document and record specific details or important information. So, if you are looking to describe something that has been observed, the term to use would be "written observation" or simply "observation".
