Browsing by Author "McDonald, Barry"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Analysis of the last page
    (Massey University, 2003) McDonald, Barry
    A sample of death notices from the New Zealand Herald was used as the basis of a Data Analysis assignment. This note explores some interesting statistical aspects of these death notices, using common data analysis techniques, and illustrates how they can be used as a resource for teaching. In particular they provide a clear example of biased sampling, a concept that is usually hard to quantify.
  • Thumbnail Image
    Item
    A teaching note on Cook's distance - a guideline
    (Massey University, 2002) McDonald, Barry
    Cook’s Distance (Di) is used for assessing influence in regression models. The usual criterion is that a point is influential if Di exceeds the median of the Fp,n-p distribution, where p is the number of regression parameters. The practice developed here at Massey Albany is to teach the guideline Di>0.7 for p=2, Di> 0.8 for p=3, Di> 0.85 for p>3, where n≥15. It is not known if this guideline is used elsewhere.