Abstract
The most effective way to learn statistics is by actively engaging in doing the statistical analysis. This idea drives this casebook. An introductory course in statistics often fails to give the students an idea of the excitement of statistics, and its relevance in the present day world. A considerable amount of material has to be covered, with no complementary time for discussion of real life examples. Students often come away with a blurred impression of formulas, and some words like ‘mean,’ ‘standard deviation,’ and ‘regression.’ The point that statistical analysis is vital to arrive at conclusions in a sensible and rational manner is often neglected. This casebook is an attempt to remedy this deficiency by providing an active resource for classroom use. The book is based on cases that we have developed through almost fifty cumulative years of teaching the introductory statistics course at New York University.
We have attempted in this casebook to present cases representing situations and contexts from a diverse set of fields, where statistical analysis is required to arrive at a meaningful conclusion. Topics covered include eruptions of the ‘Old Faithful’ geyser, the issuance of international adoption visas, the space shuttle Challenger tragedy, patterns in the Dow Jones Industrial Average and Standard and Poor’s index, health expenditures of states, random drug and disease testing, baseball free agency, performance of NBA guards, energy consumption of a household, grape yields in a vineyard, and the birth and nursing of a beluga whale calf. All of the datasets are real and complete.
Each case is motivated by a question that needs to be answered, and full background material is presented. The statistical analysis flows naturally from the question. The discussion given in the cases attempts to demonstrate the logic of the analysis and emphasize the interactive and iterative nature of the task. The aim of these cases is to show the reader by example that statistical analysis clarifies and throws light on a complex situation. It enables one to draw useful conclusions. Besides the final conclusion, much is learned about the problem during the analysis. The journey, as well as the arrival, matters.
In addition to investigation of the specific questions raised by a particular case, we hope that the reader also will develop a feel for the kind of approach to data analysis that is likely to be fruitful in general. As statistical software has become generally available, the possibilities of superficial, but inadequate, analysis of data have increased correspondingly. However, if a data analyst is trained to develop a system of general principles in performing a data analysis that are widely applicable, it is much more likely that she will analyze future data sets in a reasonable way. It is our hope that this casebook can be helpful in highlighting the kinds of questions that need to be answered if such a system is being used.