Anecdotal notes are short and simple written records of specific events or observations that happened. They help to provide important details and information about the event or observation. Full definition
What worked best for her was having one group meet at a time while she sat nearby and took anecdotal notes. (educationworld.com)
I take ongoing anecdotal notes on my reading conferences with individual students. (ascd.org)
Made data based decisions on students by taking anecdotal notes during guided reading and giving common formative assessments to analyze student data (jobhero.com)