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Can group members comment on the pro & cons of these 2 methods for
segment on attitudinal statements. When is it best use each method? Do any have glaring strengths or weaknesses vs the other. Method 1 Factor analysis and then chose the highest factor score [P factor analysis]. This essentially clusters variables. Method 2 Factor analysis & then some cluster analysis based on the factor scores. This essentially clusters respondents. Regards -- Mark Webb +27 21 786 4379 +27 72 199 1000 Skype - webbmark [hidden email] ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD |
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attitudes are usually measured by scales based on factor analysis of items.
The number of scales derived is very dependent on the actual items that were used. Many attitude domains have more than one dimension. Strict factor scores often over capitalize on chance and unique variance of items. So it is conventional to retain as many factors as you can get a good interpretation of using only items that load over some cutoff e.g., |.45| on a factor and not over some other cutoff e.g., |.30| on any other. Items that have negative signs are reflected, i.e., 1 to 5 becomes 5 to 1. Most methods for clustering cases assume that the variables that go in ae fairly indepedent, so clustering of raw items is seldom done. Scale scores are usually more appropriate. If you only have one attitude factor, clustering becomes much less meaningful. Art Kendall Social Research Consultants Mark Webb wrote: > Can group members comment on the pro & cons of these 2 methods for > segment on attitudinal statements. > > When is it best use each method? > Do any have glaring strengths or weaknesses vs the other. > > Method 1 > Factor analysis and then chose the highest factor score [P factor > analysis]. > This essentially clusters variables. > > Method 2 > Factor analysis & then some cluster analysis based on the factor scores. > This essentially clusters respondents. > > Regards > > -- > Mark Webb > > +27 21 786 4379 > +27 72 199 1000 > Skype - webbmark > [hidden email] > > ===================== > To manage your subscription to SPSSX-L, send a message to > [hidden email] (not to SPSSX-L), with no body text except the > command. To leave the list, send the command > SIGNOFF SPSSX-L > For a list of commands to manage subscriptions, send the command > INFO REFCARD > > ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
Art Kendall
Social Research Consultants |
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The method that you use really depends on what you want to accomplish.
If your goal is data reduction, then clustering of variables should be used. If, on the other hand, you want to group your cases/respondents into meaningful segments in terms of attitudes, then you would want to cluster the cases. However, the two are not necessarily mutually exclusive, you may want to cluster variables first to mitigate multicollinearity, and then cluster the cases, as Art has mentioned below. ----------------------------- Dan Zetu Analytical Consultant R.L. Polk & Co. 248-728-7278 [hidden email] -----Original Message----- From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Art Kendall Sent: Friday, May 22, 2009 7:49 AM To: [hidden email] Subject: Re: Attitudinal Segmentation methodology advice attitudes are usually measured by scales based on factor analysis of items. The number of scales derived is very dependent on the actual items that were used. Many attitude domains have more than one dimension. Strict factor scores often over capitalize on chance and unique variance of items. So it is conventional to retain as many factors as you can get a good interpretation of using only items that load over some cutoff e.g., |.45| on a factor and not over some other cutoff e.g., |.30| on any other. Items that have negative signs are reflected, i.e., 1 to 5 becomes 5 to 1. Most methods for clustering cases assume that the variables that go in ae fairly indepedent, so clustering of raw items is seldom done. Scale scores are usually more appropriate. If you only have one attitude factor, clustering becomes much less meaningful. Art Kendall Social Research Consultants Mark Webb wrote: > Can group members comment on the pro & cons of these 2 methods for > segment on attitudinal statements. > > When is it best use each method? > Do any have glaring strengths or weaknesses vs the other. > > Method 1 > Factor analysis and then chose the highest factor score [P factor > analysis]. > This essentially clusters variables. > > Method 2 > Factor analysis & then some cluster analysis based on the factor > This essentially clusters respondents. > > Regards > > -- > Mark Webb > > +27 21 786 4379 > +27 72 199 1000 > Skype - webbmark > [hidden email] > > ===================== > To manage your subscription to SPSSX-L, send a message to > [hidden email] (not to SPSSX-L), with no body text except > command. To leave the list, send the command > SIGNOFF SPSSX-L > For a list of commands to manage subscriptions, send the command > INFO REFCARD > > ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD |
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