The distinction between a diary and a reaction paper is that a diary is a location where you write and record the events of your day or event. A response paper is something you write to express your views or ideas on a certain subject. Controlled ideas are common in reaction papers. You should give your views on different topics, not just one topic like in a essay. Diaries are written at the time they occur so they provide information about what happened during those moments. On the other hand, reaction papers are written after the incident has taken place which allows you to think more critically about issues that are important to you. Furthermore, diaries are private while reaction papers can be read by others so they should be written carefully. Do not use jargon in your diary entries or reaction papers will not be understood. Also, do not write in block capitals as this is considered poor grammar today. Finally, diaries are written for yourself and help you to understand yourself better while reaction papers are written for others who may benefit from reading them.