XLSTAT: Sensory wheel

 

Goal of this article

The goal of this tutorial is to re-build the classic version of the coffee tasters’ sensory wheel displayed in  this article from coffeeandhealth.org , based on the different attributes stored in an Excel spreadsheet. Once it is drawn, a sensory wheel is very useful to help characterize a specific product with different levels of precision.

 

Dataset for Example

The data used are the attributes that can be seen in this article which displays the Coffee Flavour Wheel Adapted from that of the Specialty Coffee Association of America.
The data is available in two different formats, that can both be introduced as an input in the XLSTAT sensory wheel feature:

• The List of Words format. This format only includes the 34 most specific attributes, which are the ones that will be displayed the farthest from the center of the wheel. This format requires that the user manually edits the lower levels of the sensory wheel once it is drawn.

• The Classification table format. This format displays the different levels of attributes, from the most general (level 1) to the most specific (level 4). This format automatically provides a sensory wheel with a typical nested structure.

We will show how to draw the wheel based on each of the two data formats.

 

Setting Up

Drawing a sensory using the List of Words data format

• Open XLSTAT.

• Click on the Sensor/ Sensory profiling menu and select the Sensory wheel feature.

• The Sensory wheel dialog box appears.

 In the General tab:

• Activate the List of Words format then select the corresponding data under the Words table.

 In the Options tab:

• Set the number of levels at 4.

• Click on OK.

• The sensory wheel appears.

 

Each slice from the center to the outer circle is linked to one single attribute and is divided into 4 levels. 

• Click anywhere on the wheel to manually modify the lower levels of the wheel to obtain the desired hierarchical structure. For example, let's merge floral and fragrent into fleuri at level 3.

• You may receive a message asking you if you want to trust the XLSTAT-MXM.dll file. If this occurs, click yes.

• The below dialog box appears. Fill it in as indicated below.

• Click on Apply then Close. You can see the resulting merge in the image below:

Now we switch to drawing the sensory wheel from a more complete dataset in the form of a classification table.

 

Drawing a sensory wheel using the Classification table format

• Go back to the Sensory wheel command and fill out the general dialog box as follows:

• Click OK.

 

Interpreting the Results

The complete sensory wheel with its nested structure appears.

It can be used by coffee tasters who will be able to characterize coffee samples at different levels of specificity, going from the center to the outer part of the wheel.

This article gives more hints on the interpretation of a sensory wheel.

PS: Section widths can be controlled using an additional column of frequencies that should be introduced in the general tab of the dialog box.