Sensometrics tutorials

Organised by The Sensometrics Society

Compusense

The following tutorials, organised by the Sensometrics Society will take place on 13 September 2022 10am- 2pm. The cost is €70 + VAT : please book via the conference registration system

Tutorial 1: Multivariate Data Analysis in Sensory Evaluation (or, why PCA should be your desert island airplane)

Tutorial 2: An introduction to text analysis with R for sensory and consumer scientists

Tutorial 3:


Tutorial 1: Multivariate Data Analysis in Sensory Evaluation (or, why PCA should be your desert island airplane)
Instructor(s): John Castura, Compusense Inc., Canada, Ingunn Berget, Nofima AS, Norway

Suppose you are going to live on a desert island. As is usually the case on desert islands, you also need to analyse consumer and sensory test data while you are there. What multivariate statistical method will you bring with you? I am sure I’m not alone in making principal component analysis (PCA) a top choice. Why? PCA moves the observed results to a different coordinate system while handling the multicollinear sensory attributes, while doing data compression and data reduction along the way. The results are readily visualized and reveal patterns that might otherwise be missed. And it is key to unlocking other multivariate methods also. If you don’t already agree that PCA belongs on your desert island, by the end of this tutorial, you might.

The tutorial begins with a crash course in PCA. We describe the PCA airplane and fuel it with a data matrix, X. In flight, we describe how we get score and loading matrices from X using singular value decomposition. Then we show how the PCA results can be visualized and interpreted. Then, mid-flight, the instruments go haywire and the engines sputter! Oh no! Everyone aboard the plane parachutes to safety, and the pilot, against all odds, lands the plane safely in an emergency water landing. Everyone is okay! But we don’t want to ever have to do that manoeuvre again.

We retrieve the black box. What went wrong with PCA Flight #1 is that the original variables were measured with uncertainty, then after PCA treated as if they were not. To improve the safety of future PCA flights, we describe a bootstrap procedure for investigating uncertainty. We present research, some of it very new, for using these uncertainty estimates to investigate how well products are discriminated.

PCA Flight #2 takes flight, again fuelled by data matrix X. We can see clouds of uncertainty around the PCA results with our new instruments. These visualizations are connected to numerical results that reveal product discrimination. Interpretation focuses on the connection between the visual and numerical approaches. It is not a coding tutorial, but at cruising altitude, there will be mid-flight statistical analyses in R showing how it’s done. When PCA Flight #2 touches down for a perfect landing, the time in Turku will be about 3 hours after the tutorial departure time. Tutorial attendees will deplane having a new understanding and tools they can bring to their work, or to their desert island.

Duration: 3 hours

Audience: Sensory scientists and statisticians interested in analysis of consumer test data

Background: Basic understanding of statistics is advantageous but not required

Laptop: It is not a coding workshop so a laptop is not required. Attendees will receive a list of resources related to the topics discussed. Some R code related to examples shown in the tutorial will be provided after the tutorial to attendees.

Contingency: If it is necessary, the workshop will pivot to an online format. Tutorial registrants will receive notice of any changes in plans.


Tutorial 2: An introduction to text analysis with R for sensory and consumer scientists

Instructor(s): Jake Lahne, Leah Hamilton and Martha Calvert

Detailed information to follow


Tutorial 3

Information to follow

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