Ed Etchells from Sunnybrook has another article about the value of small sample sizes in QI. He wrote a really great article last year
http://qualitysafety.bmj.com/content/25/3/202
and now has an excellent follow up
http://qualitysafety.bmj.com/content/27/1/61
The new article has a very provocative quote that I very much agree with:
"A frequent problem in quality improvement is that people waste time collecting too much data."