Over the last two weeks, several items were posted in the fifth release.
Chapters 5 and 6. Chapter 5 and 6 were released one week apart from one another. Chapter 5 introduces large sample inference for means and proportions in one and two sample contexts. Chapter 6 introduced the t distribution for small sample inference for means. In the 2011 release, Chapter 6 will expand to incorporate simulation and permutation techniques for proportions. Both chapters draw on the foundations introduced in Chapter 4.
Chapter 4 exercises. Mine produced a set of exercises for Chapter 4 and also extended and revised some earlier sets of exercises. These sets are becoming robust and have grown throughout the project.
Chapter 4 revision. There were several updates to this chapter from the first release. The most important was consistency of conditions for applying the normal model to a sample mean. In writing Chapters 5 and 6, very concrete conditions from Chapter 4 were needed, and we also wanted to ensure they were rigorous, so we have sharpened these up. Other changes include the addition of the term “test statistic” and a new discussion on how we choose our significance level for a test, the latter added based on an inquiry by Meenal.
Over the next four weeks, our team will be developing Chapter 7, making revisions to Chapters 5 and 6, and extending the selection of exercises to new chapters. The material for the sixth release is scheduled for May 10th. We are on track to release Chapters 1-7 as a ten week coursebook (PDF) by the end of June (all chapters will be individually available in mid-May). At that time we will also lay out partial plans for the last 12 months leading up to the First Edition release.