Assessing the Effect of an Open-ended Category on the Trend in 2×K Ordered Tables

10.6339/JDS.2003.01(2).110

Shiva Gautam；Takamaru Ashikaga

Ordered categories ； score ； trend

Journal of Data Science

1卷2期（2003 / 05 / 01）

167 - 183

英文

Trend in proportion in 2×K ordered tables is evaluated by assigning scores to ordered categories. Investigators often encounter 2×K ordered tables with an open-ended category. An open-ended category arises when category scores for the first K-1 categories are known or given a priori but the score for the last category is unknown. In such situations, an arbitrary score is often assigned to the openended (or the last) category before evaluating the trend. Thus two investigator analyzing the same data set may assign different scores and may arrive at different conclusions. In the spirit of preliminary data analysis it is shown through examples that there are situations where the conclusion is not affected by the choice of scores assigned to the open-ended category. The paper also explores situations where the conclusion may depend on the choice of a score for the openended category. In the former case, the usual trend analysis may be performed after assigning a score to the open-ended category. In the latter case, the trend may be evaluated after adjusting for the open-ended category as demonstrated in this paper. Alternately, the trend may be evaluated by Gautam's method which does not depend on a particular choice of a score.