Intent to Purchase Rating
December
9, 2004 - by
Robert E. Stevens, GENESIS II
(The
Second Beginning) E-Mail: views@aol.com
One of the Views readers called to ask
if I had a historical file for Definitely Would Buy ratings. I
told him I did and I would share them with him, but I would recommend
any usage of the data be done with extreme caution.
It has been my experience that the rating scale results depend more on
the protocol than the differences between concepts. My research
has found that:
- "Definitely Would Buy" results will differ by 20%, depending on
where the data are collected (CLT vs. Mail vs. Telephone vs. In-store)
- "Definitely Would Buy" results will differ by 20% between data
collected via questionnaire (self-administered) vs. Interviewer
administered (respondent does not see the questionnaire).
- The use of the standard contingency question can add or reduce
the DWB scores by 20%
- Results will vary greatly depending on the category. For
instance, laxatives will average 16% DWB with a range of 9% - 21% while
Cake Mixes average 41% DWB with a range of 17% - 54%.
- Results from well over 1,000 studies, across 21 product
categories, show that no category falls below 9% DWB.
Two separate "Researching Research" projects that I reported on in an
early 1990s Views showed the variations
in results you can obtain with slight changes in protocols. In
the first study, six concepts were tested using questionnaires both
with and without the Definitely Would Buy contingency question.
When the contingency question was present, the average DWB score for
the six concepts was 35%. When it was not present, the average
score was 15%. In the second study, we compared results collected
in a Central Location Study with results obtained In-Store. three
concepts were evaluated through interviewer administered
questioning. The Central Location part of the study resulted in
an average DWB score of 45% while the In-Store results showed a DWB
score of 23%.
CAUTION: Never use a
company's historical data base if they cannot tell you that the
protocol used in the research was the same across the entire data
base. Demand that data used to make judgments about the results
of your test are from studies that used the same protocol and from the
same product category. Better yet, include in your study a
current product concept or some company standard concept. It may
cost a little more but in the end, you will find it to be well worth
the investment.
Know the
source of your data. Know the when, where & how your data
were collected.
Sponsor: Sorensen Associates Inc
Portland, OR: 800.542.0123
Minneapolis, MN: 888.616.0123
the
in-store research company™ -- Dedicated to the
relentless pursuit of WHY?