摘要:

ABSTRACTThe use of Individual Differences Scaling in sensory studies has been limited because the number of pairwise comparisons in a complete design can be prohibitively large. This study examines the effect of different levels of error and missing data on recovery of true structure by Individual Difference Scaling for the normal range of assessors and stimuli (8–16) used by sensory workers. Recovery was very good for a missing value rate of 20%. It was good for 40% provided that the number of stimuli was high, but deteriorated sharply at 60% missing data. The effect of superimposing random error on to the true structure indicated that a large error rate gave poor recovery. It is concluded that up to 40% of the distances in a complete design could be excluded, provided that replicate measurements indicated error levels were not sever

ISSN:0887-8250    

DOI:10.1111/j.1745-459X.1987.tb00182.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTInvestigation of the relative heights of pairs of fathers and sons led the famous 19th century scientist, Sir Francis Galton, to the concept known as “regression to the mean.” Gallon observed that sons of extremely tall or extremely short fathers tended to be less extremely tall or short. The concept has since been ‐ found to apply to virtually any experiment requiring a test‐retest design. On the average, the bottom group on the first test will tend to increase, and the top group will on average decrease on the retest. For example, a clinical study requiring an initially high blood pressure baseline value (screening value), might decrease as a group on a subsequent retest, perhaps merely due to a regression effect. One way to account for possible bias due to regression effects is by using an appropriate control group. In the absence of a control group, James (1973) has developed some useful formulas for estimating the expected regression effect, when a truncated population is being sampled. Choice of an appropriate baseline value should also be guided by consideration of the potential effects of reg

ISSN:0887-8250    

DOI:10.1111/j.1745-459X.1987.tb00183.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTTrained sensory panelists evaluated 8,12 or 18 samples of ground beef at each meeting to determine the effect of sample numbers on panelist perception of certain sensory properties. Six ground beef formulations were selected to represent a broad range of fat and connective tissue content. Panelists evaluated samples for tenderness, connective tissue amount and juiciness. Sensory ratings were affected by formulation, anticipation of sample numbers and actual number of samples (sample x session). Although panelists discriminated among formulations presented in the last six samples somewhat differently from the way they discriminated among the same formulations presented in the first six samples, there was little evidence that the panel became less sensitive.

ISSN:0887-8250    

DOI:10.1111/j.1745-459X.1987.tb00184.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTIn order to provide a deeper understanding of the workings of principal components, four data sets were constructed by taking linear combinations of values of two uncorrelated variables to form the X‐variates for the principal component analysis. These examples are believed useful for aiding researchers in the interpretation of data and they highlight some of the properties and limitations of principal components analyse

ISSN:0887-8250    

DOI:10.1111/j.1745-459X.1987.tb00185.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTChicken patties (50% light/50% dark meat) were used as training and testing samples by a 10‐member panel to develop descriptive terms appropriate for profiling the taste/aroma character notes of fresh and reheated chicken meat. A free word association list of 45 terms was developed in initial training sessions. These terms were used to obtain frequency of use and intensity data for statistical analyses to determine appropriateness of the terms for profiling and discriminating among fresh and reheat treatments of the chicken patties. The initial list was reduced to 31 terms by a frequency‐use delimiter of 40% over four replications and by MANOVA probability values (P>.05) for sample differences. FACTOR (principal components) analysis applied to the reduced list of terms indicated six logical associative groupings of terms that explained 77% variation in the data. A final list of 12 descriptors was developed by omitting redundant terms in a factor group

ISSN:0887-8250    

DOI:10.1111/j.1745-459X.1987.tb00186.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0887-8250    

DOI:10.1111/j.1745-459X.1987.tb00187.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0887-8250    

DOI:10.1111/j.1745-459X.1987.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0887-8250    

DOI:10.1111/j.1745-459X.1987.tb00181.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY