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Deriving Attribute Importance with Correlation Analysis
We often hear this question, because there is a correlation analysis embedded
in our E-Value2 Data Analysis spreadsheets. The paragraphs below describe how the
spreadsheets calculate importance, and how to interpret the results.
The correlations in our spreadsheets are between overall satisfaction and each of the
attributes and benefits. A perfect correlation would be "1," indicating
that an attribute always is rated higher by the same relative amount as
the overall satisfaction score for each individual. No correlation
would be "0," and a perfect negative correlation would be "-1."
The spreadsheets sort the attributes and benefits from high to low,
based upon correlation to overall satisfaction. In effect, this yields
"derived" importance. This differs from "stated" importance, in which
people rate the importance of each attribute. In my opinion (and in the
opinions of many others), derived importance is a superior measure.
While it is quite possible for someone to "state" that something is the
most important item, the derived importance may find it to be relatively
low in importance, as it relates to overall satisfaction. The reverse
also holds true.
By using derived importance, you can avoid focusing on improvements to
attributes that will not have a positive impact on overall
satisfaction. For example, an attribute may have a relatively low
"performance" (agreement) score, but you wouldn't want to do much about
it if it had a low correlation to overall satisfaction. The example I
like to use is "carpeting." Suppose we had included an attribute named
"I love the color of the carpeting." One wouldn't expect this to be as
highly related to overall satisfaction as "I am treated as a valued
employee" (which almost always ranks in the top ten in importance),
because it has little to do with satisfaction. I would expect the
correlation on such an item to be very low, which would indicate that
you shouldn't run out and buy new carpeting.
Now, one caveat may be in order here. Some attributes may have ranked
high in stated importance, but will be low in derived importance. This
doesn't mean that you can cut back efforts in these areas. What the
data are saying in this case is that "things are fine as is" with regard
to that particular attribute. Letting performance slip may cause an
attribute to rise in importance the next time you survey participants.
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