Re: Coding "missing values" - standards, customs, tricks of the trade?

>"A.Mair" <chgs02> wrote: >..... >I also have begun using these negative values to denote that >the question was not asked in that version of the questionnaire, >or that the self-completion part of the questionnaire was not returned. >Leading to cascades such as >use -1 for "No self-completn" >use -2 for "skp, A version" >use -3 for "skp,not in paid work" >use -4 for "skp,no disabld coworker" >This enables me to have more than the three values in missing values >by using ranges. Wouldn't it be better to code using binary powers, thus allowing any combination to be represented by one value? e.g. Using -1, -2 -4 and -8 for your four classes would mean -12 signified "Not in paid work _and_ No co-worker". Ken Turner A Member of the Computer Conservation Society ken@ivan.compulink.co.uk kentss@cix.compulink.co.uk