Category: Technical Reports

Technical Report: Discovering Time-Dependent Trends

ABSTRACT Product changes in manufacturing and storage are often time-dependent. Sometimes these changes are linear, sometimes cyclical and at other times chaotic. It is often not obvious that a time-dependent change is in fact occurring in some variable of interest.…

Technical Report: Parity Claims

ABSTRACT The recently reissued ASTM Claims Guide provides a useful classification of types of claims and recommendations concerning appropriate product testing. Figure 1 is a schematic summary of the claims discussed in that document. There are comparative and non-comparative claims.…

Technical Report: Indices of Sensory Difference: R-Index and d’

ABSTRACT Discrimination methodologies are used to investigate similarities and differences among variants of manufactured products. Applications typically involve cost savings, storage and product improvements. A researcher often requires more information than a simple test of significance which can be readily…

Technical Report: Relative Scales and DifferenceTesting Norms

ABSTRACT Appropriate treatment of “no difference” responses in paired preference and difference testing is a persistent issue in product testing. Different approaches involving their inclusion or omission from subsequent testing using the binomial distribution have been proposed. In 1980, paired…