Discriminability and uncertainty in principal component analysis (PCA) of temporal check-all-that-apply (TCATA) data

John Castura/ August 26, 2021/ Peer-reviewed Paper/ 0 comments

Temporal check-all-that-apply (TCATA) data can be summarized and explored using principal component analysis (PCA). Here we analyze TCATA data on Syrah wines obtained from a trained sensory panel. We evaluate new and existing methods to explore the uncertainty in the PCA scores. To do so, we use the bootstrap procedure to obtain many virtual panels from the real panel’s data.

Consumer hedonic studies with incomplete block designs

John Castura/ August 25, 2021/ Workshop/ 0 comments

Castura, J.C. (2021). Consumer hedonic studies with incomplete block designs. In: Workshop: A journey of consumer segmentation. History and a discussion of current “preference” segmentation approaches based on incomplete and complete test designs (Zach, J., Rothman, L., Carr, B.T., Thomas, H., Castura, J.C.). 14th Pangborn Sensory Science Symposium, 9-12 August. Online. (Workshop Oral). DOWNLOAD

Temporal Rate-All-That-Apply (TRATA): A novel temporal method for sensory evaluation

John Castura/ August 8, 2021/ Poster/ 0 comments

This study introduces temporal rate-all-that-apply (TRATA) as a new temporal sensory method. It was inspired by rate-all-that-apply (RATA) and temporal check-all-that-apply (TCATA), but is most similar to multiple-attribute time intensity (MATI) in that the TRATA method allows for simultaneous rating of attribute intensities over time. Only attributes that are perceived are scaled. In this case study, the TRATA method was

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Temporal ranking for the characterization and better discrimination of protein beverages with different sweeteners

John Castura/ December 9, 2020/ Poster/ 0 comments

This study proposes the application of ranking to temporal product evaluation to differentiate attribute dominances over time. The ability of the proposed method to discriminate sensory differences was compared to temporal check-all-that-apply (TCATA), a discriminating temporal method for capturing the temporal profile of food and beverage products.

Analyzing data using the chance-corrected beta-binomial model: Parameter estimates and their confidence regions

John Castura/ August 6, 2019/ Poster/ 0 comments

Data arising from replicated sensory discrimination test methods with a correct response are often modelled using the chance-corrected beta-binomial distribution. The model can provide maximum likelihood estimates of the mean proportion of correct responses in the population (and discriminal distances under Thurstonian assumptions) and of the assessor heterogeneity (overdispersion). Both of these parameters are estimated with uncertainty. Previously uncertainty associated

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Analysis of sensory check-all-that-apply (CATA) data which includes the evaluation of a single ideal product

John Castura/ August 6, 2019/ Poster/ 0 comments

When evaluating samples in sensory tests, consumers are sometimes asked not only about real samples but also about imagined ideal products. Check-all-that-apply (CATA) questions are one way to understand consumers’ perceptions of products and their ideal product. We propose the following statistical analyses of consumer CATA data: (i) confidence intervals for head-to-head comparisons based on CATA data; (ii) panel (dis)agreement

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A retail simulation study for investigating product choice and choice satisfaction: A case study involving kombucha

John Castura/ August 6, 2019/ Poster/ 0 comments

Kombucha is a fermented tea that is rapidly growing in popularity in the United States. As part of a larger consumer study conducted in Portland, Oregon, kombucha consumers (n=1303, 68% female, aged 18-86, USA)participated in an online retail simulation test. They evaluated 9 commercial products (bottle images) and made choice selections in a retail simulation.

Does the τ estimate from same-different test data represent a relevant sensory effect size for determining sensory equivalency?

John Castura/ July 1, 2019/ Peer-reviewed Paper/ 0 comments

Analysis of data arising from the same-different test method can be submitted to Thurstonian-derived modelling with the goal of estimating the sensory distance between two products (the discriminal distance δ) and the response bias for responding “same” (τ). Previously it has been proposed that it is possible to use τ estimates from same-different test data to represent the consumer-relevant effect

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Segmenting consumers based on food choice motivation and product benefit expectations: A case study involving Kombucha

John Castura/ June 30, 2019/ Poster/ 1 comments

Kombucha is a fermented beverage that is rapidly growing in popularity in the United States. As part of a larger consumer study conducted in Portland, Oregon, kombucha consumers (n=230) participated in a retail simulation in a central location test. They evaluated 9 commercial products, made choice selections, and were prompted with questions related to food choice motivations, product expectations and

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