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
Rule of recognition if the rule of recognition were "what Professor X says is law", then any rule that Professor X spoke would be a valid legal rule. It follows that the rule of recognition is but a factual acknowledgement of what is indeed law; as per the classic illustration of a bill passed by the legislative authority and assented to by a Head-of-State. The fact that the bill has been made law in accordance with proper parliamentary procedure shall, in accordance with the Rule of Recognition, render it valid law. Again, this is primarily based on the fact of its existence in