A STATISTICAL TEST FOR RANKING DATA FROM PARTIALLY BALANCED INCOMPLETE BLOCK DESIGNS

• Published in: Journal of sensory studies Vol. 26; no. 1; pp. 81 - 84
• Main Authors: BEST, D.J., RAYNER, J.C.W., ALLINGHAM, DAVID
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01-02-2011; Wiley
• Subjects: Biological and medical sciences; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Methods of analysis, processing and quality control, regulation, standards
• ISSN: 0887-8250; 1745-459X
• DOI: 10.1111/j.1745-459X.2010.00324.x

ABSTRACT
The analysis of partially balanced incomplete block (PBIB) ranked data is discussed. Two examples are given to illustrate two alternative approaches. Analysis of PBIB ranking data is not covered in any of the standard sensory evaluation texts and this expository note is meant to help fill this gap. For some data sets, the calculations for the first approach are simple enough to do by hand. The second approach that we consider assumes that computer software for general analysis of variance is available. Such analysis of variance software should cope with missing values via a regression method. A suggested multiple comparisons algorithm is also illustrated. R code is given to allow easy application of our first approach.
PRACTICAL APPLICATIONS
Sensory fatigue can be a problem in some sensory evaluation trials. In the taste‐test area, this is sometimes called “palate paralysis.” To cope with this fatigue, balanced incomplete block designs can be employed. However, these restrict the sensory scientist to particular combinations of products, subjects and evaluations per subject. Sometimes, such restrictions can be prohibitive, and then partially balanced designs, which allow more freedom in the choice of these parameters, can be used. Here we consider statistical analysis of ranking data from partially balanced incomplete block designs.