User Guide

544
Chapter 38
issue—differences in scaling may affect your solution. If your variables have large
differences in scaling (for example, one variable is measured in dollars and the other
is measured
in years), you should consider standardizing them (this can be done
automatically by the Multidimensional Scaling procedure).
Assumptions. The Multidimensional Scaling procedure is relatively free of
distributi
onal assumptions. Be sure to select the appropriate measurement level
(ordinal, interval, or ratio) under Options to be sure that the results are computed
correctly.
Related pr
ocedures.
If your goal is data reduction, an alternative method to consider is
factor analysis, particularly if your variables are quantitative. If you want to identify
groups of similar cases, consider supplementing your multidimensional scaling
analysis
with a hierarchical or k-means cluster analysis.
To Obtain a Multidimension a l Scaling Analysis
E From the menus choose:
Analyze
Scale
Multidim
ensional Scaling...
Figure 38-1
Multidimensional Scaling dialog box
E In Distances, select either Data are distances or Create distances from data.