Graduate students

This site provides an introduction to basic statistical concepts for journalists and writers with little math background. Key Words: Mean; Median; Percent Changes; Per capita; Rates; Standard Deviation; Normal Distribution; Margin of Error; Confidence Interval; Data Analysis; Sample Sizes; Statistical Tests; Student's T.

This collection of datasets, posted by UCLA, is divided into 6 groups: Datasets for Teaching; Data from Books; Data from Consulting Projects; Data from National Statistics Agencies; Social Science Data Archives; Data from US Governmental Agencies. The data from books come from the following authors: Petruccelli, Nandram and Chen; Freedman, Pisani, and Purves; Andrews and Herzberg; Carlson and Thorn; Cox and Snell; Hand, Daly, Lunn, McConway and Ostrowski; and Moore.

This collection of datasets comes from several phases of drug research. Each dataset comes with a full description and questions to answer from the data.

This Flash based applet simulates data from a case study of treatments for tumor growth in mice. This simulation allows the user to place mice into a control and treatment groups. The simulation then compares the difference in the groups based on this haphazard selection to those of a truly random assignment (the user may also create multiple random assignments and examine the sampling distribution of key statistics). The applet may be used to illustrate three points about random assignment in experiments: 1) how it helps to eliminate bias when compared with a haphazard assignment process, 2) how it leads to a consistent pattern of results when repeated, and 3) how it makes the question of statistical significance interesting since differences between groups are either from treatment or by the luck of the draw. In this webinar, the activity is demonstrated along with a discussion of goals, context, background materials, class handouts, and assessments. Key Note for Instructors: The data are drawn from a real experiment with an effective treatment but where the response is correlated with animal age and size (so tumor size will tend to be smaller in the treatment group when measured at the end of a randomized experiment but animal age and size should not be). Typically people choosing haphazardly will tend to pick larger/older animals for the treatment group and thus create a bias against the treatment.