Dear Diane

I hope this makes sense.

First the mathematical trick. The mean is total divided by no of cases. Thus the total is the mean multiplied by the no of cases. A easy way to do mean substitution on a case basis is to calculate the mean of the valid subscales and then multiply it by the actual number of subscales in the scale.

You are half-way there.

75% of 17 question subscale means you require at least 13 subscales to be present. That implies that you want the number after the '.' in the mean statement to be 13. This also works for sum but because you need mean substitution it is easier to work with the mean and multiply out.

Thus you need the statement like

COMPUTE xbar = MEAN.13(pjss1 to pjss17)*17.

If you want to do this via Compute dialogue then you need to type in the numeric expression box.

MEAN.13(pjss1 to pjss17)*17

Jean M. Russell

Date sent: Tue, 15 May 2001 16:02:23 -0400 Send reply to: "Cohen,Diane" <dc42@EXCHANGE1.DREXEL.EDU> From: "Cohen,Diane" <dc42@EXCHANGE1.DREXEL.EDU> Subject: Compute total with 25% missing answers To: SPSSX-L@LISTSERV.UGA.EDU

> Dear Folks, I have a subscale with 17 items for which I calculated a > total score (with ease, remarkably enough!). Now I need help with for > the cases in this scale in which the respondant answered 75% or more > of the items. I saved the syntax you all sent on how to do this with > another scale where the total score was a mean of all responses: > COMPUTE xbar = MEAN.12(pjss15 to pjss30). EXECUTE I thought if I > fiddled around with it somehow I could figure it out, but no cigar. I > would like to try it thru the compute command rather than syntax if > anyone has the patience to tell me how to do it. I imagine it has an > "if" statement, but when I went into that section I became even more > lost. Thanks in advance, Diane d'Newbie

------------------------------------------------------ Jean M. Russell M.A. M.Sc. J.Russell@sheffield.ac.uk Corporate Information & Computing Services, University of Sheffield 285 Glossop Road Sheffield S10 2HB United Kingdom Phone: 0114-222-3098 Fax : 0114-222-3040