Blind Wine Part II: The Survey

Minitab Blog Editor 22 July, 2014

In Blind Wine Part I, we introduced our experimental setup, which included some survey questions asked ahead of time of each participant. The four questions asked were:

  1. On a scale of 1 to 10, how would you rate your knowledge of wine?
  2. How much would you typically spend on a bottle of wine in a store?
  3. How many different types of wine (merlot, riesling, cabernet, etc.) would you buy regularly (not as gifts)?
  4. Out of the following 8 wines, which do you think you could correctly identify by taste?
    • Merlot
    • Cabernet Sauvignon
    • Pinot Noir
    • Malbec
    • Chardonnay
    • Pinot Grigio
    • Sauvignon Blanc
    • Riesling

Today, we'd like to take a look at the results of the survey to answer some questions about our participants.

We wanted to make sure that our participants covered a broad range of wine drinkers and, most important, covered a broad range of possible responses to question #1.  Here are the distributions of responses to the first three questions:

Distribution of Responses

We were satisfied with the range and distribution of answers to those questions. Given that we had already selected which wine types to include, we were curious which wines participants believed they could identify by taste. The bar chart below shows how many out of the 13 participants indicated they could select that wine, with those included in the experimented in red*:

Wines You Could Identify

* The default color in Minitab for the second group on any graph with attributes being controlled by groups is not actually called "red" but rather "wine," a clear indication this experiment was meant to be.

For most wines, only about 50% of participants felt they could identify them by taste alone.  At this point they did not know the nature of the wine tasting, but must have been starting to get some ideas...

Next we wanted to see if there were any relationships between responses to different questions. For example, do participants with greater self-identified wine knowledge spend more on wine, or buy more types of wine?

Wine Knowledge versus Money Spent and Types Bought

While there was no evidence that claiming more knowledge is related to how much participants spent per bottle, there was a significant relationship with how many different types they bought regularly (p = 0.001, R-Sq = 66.2%). Perhaps those less knowledgeable stick to a few known types and spend more to make up for a lack of knowledge? And could it be that those with more knowledge buy a large variety, but know how to select without spending too much? We can't say definitively, but the results give some possibilities to consider.

We also wanted to test whether people who claim more wine knowledge (and who, we know from above, buy more types of wine regularly) would also claim to be able to identify more of the listed types:

N Identifiable vs Wine Knowledge

Again we see a significant relationship (p = 0.000, R-Sq = 70.6%), indicating that familiarity with many types of wine is closely linked with self-identified wine knowledge.

So with our survey results in hand, we see that:

  • We have a good distribution of participants
  • Participants who claim more knowledge don't tend to spend more money per bottle
  • Perceived wine knowledge is closely related with familiarity with a broad range of wine types

How well do you think the survey results will align with the experimental results?