David P. Doane

Measuring Skewness: A Forgotten Statistic?

This paper discusses common approaches to presenting the topic of skewness in the classroom, and explains why students need to know how to measure it. Two skewness statistics are examined: the Fisher-Pearson standardized third moment coefficient, and the Pearson 2 coefficient that compares the mean and median. The former is reported in statistical software packages, while the latter is all but forgotten in textbooks. Given its intuitive appeal, why did Pearson 2 disappear? Is it ever useful? Using Monte Carlo simulation, tables of percentiles are created for Pearson 2. It is shown that while Pearson 2 has lower power, it matches classroom explanations of skewness and can be calculated when summarized data are available. This paper suggests reviving the Pearson 2 skewness statistic for the introductory statistics course because it compares the mean to the median in a precise way that students can understand. The paper reiterates warnings about what any skewness statistic can actually tell us.

Aesthetic Frequency Classifications

This Department will carry articles of high quality on all aspects of computation in statistics. Papers describing new algorithms, programs, or statistical packages will not contain listings of the program, although the completely documented program must be available from the author. Review of the paper will always include a running test of the program by the referee. The description of a program or package in this Department should not be construed as an endorsement of it by the American Statistical Association or its Committees, nor is any warranty implied about the validity of the program. The Editorial Committee will be pleased to confer with authors about the appropriateness of topics or drafts of possible articles.

Using Beam and Fulcrum Displays to Explore Data

Abstract The beam-and-fulcrum display is a useful complement to the boxplot. It displays the range, mean, standard deviation, and studentized range. It reveals the existence of outliers and permits some assessment of shape. Embellishments to the beam-and-fulcrum diagram can show the item frequency, and/or a confidence interval for the mean. Its intuitive simplicity makes the beam-and-fulcrum an attractive tool for exploratory data analysis (EDA) and classroom instruction.

Plan fulfillment and growth in Soviet ministries

Abstract Plan fulfillment and growth-rate performance of Soviet industrial nondefense ministries for 1966–1979 are analyzed and compared. Comparisons between partial and annual plan-fulfillment results provide insights into three aspects of ministerial behavior: storming, output shifting, and the question of whether ministerial plans are firm or changed during the course of the year. The extent to which centralization of supervision explains interministerial differences in annual plan fulfillment and growth is also explored. Regression analysis is used to test impact of plan fulfillment, time, and ministry type on growth-rate performance.

Information requirements prototyping for decision support systems

Information requirements determination for Decision Support Systems (DSS) is often inadequately handled due to premature structuring thus precluding dynamic changes in the framing of the problem by managers. A review of relevant concepts in the behavioural decision making literature is provided. Case studies from three large business organizations illustrate system problems with information requirements. The authors suggest prototyping as a more valid approach to determining information requirements.

Using the studentized range to assess kurtosis

Abstract Because it is easy to compute from three common statistics (minimum, maximum, standard deviation) the studentized range is a useful test for non-normality when the original data are unavailable. For samples from symmetric populations, the studentized range allows an assessment of kurtosis with Type I and II error rates similar to those obtained from the moment coefficients.

Assessing Textbook Coverage of Quality Topics in Business Education

Abstract Textbooks in introductory statistics and production operations management during three time periods (1982, 1985–1988, and 1989–1992) were examined for their coverage of topics relevant to total quality management (TQM). Business statistics textbooks during the first two periods provided little coverage of quality, but there was a sharp improvement in the most recent period. Production and operations management textbooks contain much stronger coverage than statistics textbooks. Textbook publishers are addressing the growing importance of TQM, but textbooks tell only part of the story. This article identifies factors that may influence classroom coverage of TQM, suggests ways to strengthen teaching of TQM, and proposes future directions for research.