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*Includes complimentary R Training on the first day. For academic and multiple registration discounts, please contact us before registering. contact us

This course has been developed for technical and supervisory personnel involved in all aspects of sensory and consumer research.


Difference Testing and R Training

April 5 - 8, 2022

In-person attendance | $1,575*

Virtual attendance | $1,175*

R Training Only

In-person or virtual attendance | $495





  • Printed manuals of slides and exercises

  • 3-month free software trial of IFPrograms® Professional 

  • A printed copy of our book, Tools and Applications of Sensory and Consumer Science and PDF downloads of the following 2 books: Thurstonian Models: Categorical Decision Making in the Presence of Noise and Readings in Advertising Claims Substantiation.

The instructors for this course will be:


The Institute for Perception


The Institute for Perception

Will Russ.png

The Institute for Perception


Molson Coors Beverage Company

Difference Testing & R Training

Tuesday, April 5  |  9am - 5pm ET


  • Welcome and introductions

  • Introduction to R

    • R and RStudio® 

    • How to write scripts

    • Useful commands

    • Functions for statistical analyses

    • Packages and libraries

  • Data Analysis

    • Importing data (Including CSV, XLSX, SPSS, SAV, etc.)

    • Data wrangling, cleaning, and manipulation

  • Scripting and Project Managment

    • Writing custom functions

    • Data Structures

    • Visualization

    • Data export

  • Project Organization and Managing Workflow

    • Git and GitHub (version control)

Wednesday, April 6  |  9am - 5pm ET


  • Introduction

    • Methodological and analytical review of sensory measurements

    • Overview of sensory discrimination testing

    • Background to workshop’s illustrative scenarios

  • Project 1: Flavor improvement of a chocolate-based snack

    • Introduction of the 2-AFC and 3-AFC methodologies
      IFPrograms exercises

    • Standard statistical approach: Binomial test and 95% confidence level

  • Project 2: Ingredient change of a baked good product – Product “match”

    • Introduction of the duo-trio and triangle methodologies

    • Finding inconsistencies and low confidence in experiment conclusions – IFPrograms exercises

  • Proportion of discriminators in the population

    • Background and why it is misleading

  • Introduction of a theoretical structure for sensory measurements

    • Illustrative examples based on peered-reviewed research

    • Expanding a purely statistical state-of-mind by incorporating decision processes – IFPrograms exercises

    • Thurstonian Theory: Introduction of a standardized
      measure of sensory difference, δ, and of its estimate d’

  • Thurstonian structure for sensory measurements

    • Application of basic principles to intensity and hedonic rating scales

    • Application to ranking and Check-All-That-Apply (CATA) scoring

    • Estimating the size of sensory differences – IFPrograms exercises

  • Back to Project 1 and Project 2

    • Data analyses and interpretation; resolution of result inconsistencies – IFPrograms exercises

  • Why a difference will always be found: The need to estimate consumer relevance

    • Preference testing to establish importance/relevance

    • Introduction of the beta-binomial model to handle test replications

    • Application to Project 1 and Project 2 – IFPrograms exercises

  • Beyond the traditional triangle and duo-trio tests: The tetrad method

    • Illustration of the reason behind the tetrad method’s superior statistical power

    • Review of published case studies confirming the tetrad’s superiority

    • The importance of giving the proper task instructions

  • Case Study: A significant consumer preference despite a lack of statistical sensory difference – IFPrograms exercises

Thursday, April 7  |  9am - 5pm ET


  • Next Step: The limitations of focusing solely on statistical significance

    • Illustration of the differences in statistical power of common sensory discrimination methods – IFPrograms exercises

    •  The need to estimate the importance of a sensory difference: Consumer relevance and δR

    • Simulations and estimates of optimal sample sizes – IFPrograms exercises

  • Establishing the size of a consumer relevant sensory difference: Using the same-different method

    • Overview of the same-different method

    • Are two samples the same or different? The tau criterion

    • Application to Project 1 and Project 2 – IFPrograms exercises

    • Research involving linking internal and consumer panel sensory sensitivities – IFPrograms exercises

    • Building a successful sensory testing program: Type I and Type II errors,  methodology, panelists, sample size, consumer relevance (δR)

  • Establishing the suitability of a switch to the tetrad method

    • Review of experimental variables: Training, retasting, memory

    • Beverage research to study the switch from triangle to tetrad – IFPrograms exercises

Friday, April 8  |  9am - 1pm ET


  • Latest developments: Difference or equivalence testing

    • Contrasting difference and equivalence testing

    • Reframing Project 1 and Project 2 in terms of difference (Project 1) and equivalence (Project 2) testing

    • Potential issues with traditional power concept for equivalence testing: Varying sample sizes – IFPrograms exercises

    • Why the concept of proportion discriminators is also misleading for equivalence testing

  • Theoretical illustrations of the switching roles of α (incorrectly rejecting no difference) and β (incorrectly accepting no difference)

    • Graphical representation – IFPrograms exercises

  • Practical application of difference and equivalence testing

    • Revisiting the previous power and sample size considerations of Project 1 and Project 2

    • Why experimental parameters must by modified for equivalence testing (Project 2)

    • Development of a broad sensory discrimination testing program for difference and equivalence testing objectives
      - IFPrograms exercises

  • Review of all covered materials and workshop conclusions 


Please enter your information below to register for this course. Those registering 2 or more attendees from the same company are eligible for a 10% discount on the 2nd registration. Please contact us before registering if you are eligible for a discounted rate. 

Apr 2022 Program Registration
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