# Cluster analysis, what to do with different scales?

I want to identify different groups of respondents out of up to five variables of the European Values Study 2008.

At first I took 4 questions for cluster analysis all on a scale from 1 to 10. However, after performing a TwoStep cluster analysis the silhouette measure was close to zero and thus indicating a poor solution.

Therefor I'd like to take some other variables. I was thinking about:

• how often discuss politics with friends [scale from 1(frequently) to 3(never)]
• describe your state of health these days [scale from 1(very good) to 5(very poor)]
• most people try to take advantage of you or try to be fair [scale from 1(most people would try to take advantage of me) to 5(most people would try to be fair)]
• Why are there people in this country who live in need? Which one reason do you consider to be most important? (four options: because they are unlucky; because of laziness and lack of willpower; because of injustice in our society; it’s an inevitable part of modern progress)

My knowledge of cluster analysis is based on Marija J. Norušis PASW Statistics 18 Statistical Procedures Companion and whatever I can find on the internet. Unfortunately, I'm not able to find answers to these questions:

1. Should I recode the answers so that they are all on the same scale?
2. Is there anything I should do with the 4-option question?

Thank you

1) You should rescale the ordinal variables. If you don't have command for that I think y = (x-min(x))/(max(x)-min(x)) will do the job.