Daniel M. Ennis

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In the dual pair method, the subject is presented with two stimuli in two pairs: One pair is composed of two samples of the same stimulus; the other pair is composed of two samples of different stimuli, one being the same as that in the identical pair. The task of the judge is to select the most different pair. The psychometric function for the dual pair(More)
A popular product testing procedure is to obtain sensory intensity and liking ratings from the same consumers. Consumers are instructed to attend to the sensory attribute, such as sweetness, when generating their liking response. We propose a new model of this concurrent ratings task that conjoins a unidimensional Thurstonian model of the ratings on the(More)
In statistical applications, such as a comparison of two items, it is useful to know whether one item is equivalent to another. Similarly it is often desirable to know whether one item can act as a substitute for another. Applications of the concept of equivalence include blend and flavor modifications of products, substitution of generic drugs for(More)
A model for the multiple dual-pair method, a generalization of the traditional dual-pair (4IAX) paradigm, is given. This model is expressed in terms of normal and beta distributions. This generalization allows for the simultaneous estimation of the perceptual distances among three or more stimuli. This model has applications in cases in which multiple(More)
Earlier data showed that subjects presented with two samples of distilled water and one of tap water were significantly more consistent in choosing the tap water as preferred than in identifying it as the odd sample in the set. The results were sometimes interpreted as demonstrating greater sensitivity for hedonic judgments than for oddity judgments. They(More)
Probabilistic models of same-different and identification judgments are compared (within each paradigm) with regard to their sensitivity to perceptual dependence or the degree to which the underlying psychological dimensions are correlated. Three same-different judgment models are compared. One is a step function or decision bound model and the other two(More)
The search for minimum clique coverings of graphs appears in many practical guises and with several possible minimization goals. One reasonable goal is to minimize the number of overall cliques in a covering, while a second less well-studied but equally reasonable goal is to minimize the number of individual assignments of vertices to cliques. Both goals(More)