From: Donald Rubin Sent: Thursday, December 8, 2016 12:43 AM To: jeffrey E. Subject: Re: Placebo effects, EB, etc. l'= speaking the Adriaan Tuiten tomorrow at 6:30 am our time, and l'=E204ol try to arrange a skype call. It cannot be tomorrow =ecause I'm in a deposition all day. On =ec 7, 2016, at 6:57 PM, Donald Rubin =rote: Sorry for the delay. Had meetings all day with a former =hD student and a current student. Not a silly question. I think =hat it has a lot to do with how data are collected and who summarizes =hem. With recorded data there is often a lot of rounding, =runcating, heaping (meaning on nice round numbers, as in age heaping), =nd "filtering" meaning by the data collector to avoid =eporting suspicious values that could lead to scorn. In some =ontexts we also have scores that are averages of many values or =ffects, which push toward the gaussian by the CLT; for example, I =sed to work at ETS, and exams are notorious for those effects. =nbsp;Theoretical distributions like the Cauchy are almost always just =pproximations because machines or people cannot record data with an =nfinite number of places. I think your question is relatively =eep with a variety of answers depending on the context and could change =s we get better at recording data. :) On Dec 7, 2016, at 12:52 PM, jeffrey E. [email protected] <mailto:[email protected]» wrote: query, why are so many distributions in nature =o consistent and accurate. doesnt it give you pause. =nbsp;. like centrigal force. not a true force but =ne we sense. many distributions could be describeds as =seudo forces pushing the tails toward the mean.. . could =ravity be one of these pseudo type forces pushing things towards = distribution.?? not as silly a question as it first might =ppear to be . :) On Wed, Dec 7, 2016 at 1:47 PM, Donald Rubin > wrote: Think =0. Where will you be? On Dec =, 2016, at 12:25 PM, jeffrey E. <[email protected]> wrote: ar you around on the =ee