tag:blogger.com,1999:blog-6011819629479820934.post4288368699296625096..comments2017-03-01T14:59:44.715+05:30Comments on Perspective...People...Passion: Whatâ€™s missing from our answers?Pankaj Kumar Shahhttps://plus.google.com/113220980719369716364noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-6011819629479820934.post-74600464511142945552014-12-29T07:56:31.463+05:302014-12-29T07:56:31.463+05:30BTW, there's a language assumption in both of ...BTW, there's a language assumption in both of those questions. For example, in SPSS (a statistical package I use), a missing value causes any boolean expression to no be evaluated. Yes, this causes (A OR B) to never be true if either is missing!!! <br /><br />The effect of this for the first problem is that the additions and subtractions can't be performed; they cause missing values if either A or B is missing.<br /><br />For the second problem, the if statements can't be executed if there are missing values.<br /><br /><br />For SAS, a more prominent language, missing values are assigned the smallest possible value in the format used. Therefore, if A is missing and B is anything else, (A>B) is never true. Also, missing values in arithmetic propagate, as in SPSS.<br /><br /><br /><br />Barryhttp://www.blogger.com/profile/04735814736387033844noreply@blogger.com