Date: Sun, 10 Oct 2010 16:43:16 -0400
Reply-To: Nabaneeta Saha <firstname.lastname@example.org>
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: Nabaneeta Saha <email@example.com>
Subject: Re: PCA with categorical (0/1) variables
Thank you Hector. I deleted those two variables from the analysis bcoz they
did not have any positive cases. But when I ran the analysis again by
imputing missing values with the mode - the output says some of the
variables have zero variances due to treating massing values as passive or
listwise, so the command could not be executed. I do not understand this.
Should I treat the missing values as extra caterogy. What does the option
treating missing value with extra category imply.
Thank you once again.
On Sun, Oct 10, 2010 at 12:16 PM, Nabaneeta Saha <firstname.lastname@example.org> wrote:
> Hi all,
> I am trying to do a PCA with SPSS. I am doing it from the optimal scaling
> options with categorical principal components. All my variables are
> presence/absence (1/0) data. I have 29 variables and 13,000 samples. But I
> am not getting any output - it says
> "A case(s) has only missing data on the active variables, all to be
> treated as passive. The case(s) is handled as a supplementary object
> (s).The following variables have less than 3 valid active cases: Q7B41,
> QQ7B31. Only the Descriptive Statistics tables can be computed. This
> command is not executed"
> I cannot understand the output, what does active variables mean? It would
> be very helpful for me if I could get some suggestions and help regarding
> Thank you,