School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, USA.
Faculty of Agro-Industry, Chiang Mai University, Chiang Mai, Thailand.
J Sci Food Agric. 2019 Oct;99(13):5696-5701. doi: 10.1002/jsfa.9832. Epub 2019 Jul 11.
In duplicated ranking tests, panelists either rank duplicates separately (2SS) or jointly in a single session (1SS). This study compared data analyses of duplicated yellow color intensity rank data using Friedman versus Mack-Skillings (M-S) tests. Panelists (n = 75) ranked an orange juice set twice - a similar-samples set (100%, 95% versus 90%); samples other than the 100% juice were prepared by dilution with water. Rank sum data were obtained from (a) intermediate ranks from jointly re-ranked scores of 2SS for each panelist, and (b) joint rank data of all panelists from the two replications in 1SS. Both (a) and (b) were analyzed using the M-S test. The median rank data (c) for each panelist from two replications were analyzed using the Friedman test.
Comparing M-S with the Friedman tests, the former generally produced higher test statistics and lower P-values than the latter. However, when considering the pattern of post hoc pairwise significant differences, both tests yielded similar conclusions.
This study demonstrated that, in a duplicated ranking test with three samples that were very similar in color, separating the two replications into two complete individual ranking tests or serving sessions (2SS) may prevent sensitivity loss due to fatigue that is otherwise experienced when evaluating all samples together in a single session (1SS). We expected to find the M-S test to be more sensitive than the Friedman test; however, this hypothesis was not supported by the post hoc (Tukey's honest significant difference (HSD)) multiple comparison test results under the specific test conditions in this study. © 2019 Society of Chemical Industry.
在重复排序测试中，评审员要么分别对重复项进行排序（2SS），要么在一次会议中联合对重复项进行排序（1SS）。本研究比较了使用 Friedman 检验与 Mack-Skillings（M-S）检验分析重复黄色强度等级数据的结果。75 名评审员两次对橙汁样本进行了排序——一组是相似样本（100%、95%和 90%）；除了 100%果汁之外的样本都是用水稀释制成的。等级和数据是从以下两个方面获得的：（a）每位评审员对联合重新排序的 2SS 分数的中间等级，以及（b）1SS 中两次重复的所有评审员的联合等级数据。这两方面都用 M-S 检验进行了分析。每位评审员的两个重复实验的等级中位数（c）用 Friedman 检验进行了分析。
将 M-S 检验与 Friedman 检验进行比较，前者通常产生更高的检验统计量和更低的 P 值，而后者则不然。然而，考虑到事后两两显著差异的模式，这两种检验得出了相似的结论。
本研究表明，在一项具有三个颜色非常相似的重复排序测试中，将两个重复实验分为两个完整的个体排序实验或评估会话（2SS），可能会防止由于在单个会话中同时评估所有样本而导致的疲劳引起的敏感性损失。我们期望 M-S 检验比 Friedman 检验更敏感；然而，在本研究的具体检验条件下，事后（Tukey 诚实显著差异（HSD））多重比较检验结果并不支持这一假设。 © 2019 英国化学学会。
