Writing is commonly used as a form of therapy or part of therapy. It has long been recognised as having positive effects. One of the best known approaches is that of expressive writing. Pennebaker proposed that three writing sessions of about 20 minutes each over 3 days about a stressful event can have positive effects. Many studies have been conducted, often adjusting the paradigm with different instructions or set ups. There is some evidence that it works under particular conditions. There are large individual differences. Pennebaker saw that writing is a window into cognitive and emotional processes. There are many other writing approaches. Sometimes the writing is analysed, sometimes it is thrown away without being read. Writing can take pace individually or in groups.