Peak–end rule end. The effects of the duration of an experience upon retrospective evaluation are extremely slight. Fredrickson and Kahneman labeled this phenomenon "duration neglect". The peak–end rule is applicable only when an experience has definite beginning and end periods. A 1993 study titled "When More Pain Is Preferred to Less: Adding a Better End" by Kahneman, Fredrickson, Charles Schreiber, and Donald Redelmeier provided groundbreaking evidence for the peak–end rule. Participants were subjected to two different versions of a single unpleasant experience. The first trial had subjects submerge a hand in 14 °C water for 60 seconds. The second trial had subjects
Chatham House Rule so that better international relations may be achieved. The rule is now used internationally as an aid to free discussion. The original rule of 1927 was refined in October 1992 and again in 2002. Chatham House has translated the rule into Arabic, Chinese, French, German, Portuguese, Spanish and Russian. The rule is a contrast (or a compromise) between private meetings, where revealing what was said in the meeting is forbidden, and "on the record" events where the discussion is completely public and attributed. Generally, the Chatham House Rule is imposed as a condition of being allowed to attend a meeting