XLSTAT: TURF Analysis in Excel 

 

Dataset for Example

The data comes from ratings by 185 customers on 27 dishes. Scores are given on a scale of 1 to 5 in response to the question "Would you buy the product?" (1: no, not at all to 5: Yes, quite sure). The goal here is to obtain a product line consisting of 5 dishes that will be sold in some stores. It should be constructed such that the market share of this line is as strong as possible.

We use the TURF method (Total Unduplicated Reach and Frequency), which provides a product line that has the highest penetration. All combinations of 5 products among all products are tested in order maximize the chance that at least one of these products is consumed.

 

Setting Up

• Open XLSTAT.

• Click on the Sensory/ Preference data menu and select the TURF analysis feature.

• Once the button is clicked, the dialog box appears. You can then select the data on the Excel sheet. You must select all products as  data.

In the General tab:

• The Variable labels option is left enabled because the first line of the column of data includes the product name.

• The size of the subset is 5. The scale being 1 to 5, we select as a scale 1-5.

In the Options tab:

• The number of combinations to be displayed is 10. Thus, the 10 best lines of 5 products will be displayed.

• Then, you define the goal. In our case, we consider that a consumer will buy the product if he gives a score of 4 or 5. The method used is the enumeration that will necessarily give the optimal result.

• Click on the OK button to launch the computations.

• The results are displayed on a new Excel sheet.

 

Interpreting the Results

The first table shows the achievement frequencies per product.

The next table lists the top 10 product combinations with their reach (number of consumers intending to buy at least one product, max 185) and frequency (times a product line scored 4 or 5, max 925).

The following table gives the same information in percentages.

This analysis identifies a product line—products 14, 15, 16, 23, and 26—with strong market potential, reaching 129 consumers, nearly 70% of the total.