Dear readers,
This my last post to this blog. Why? Because I’ve said all I have to say about performance. I could make up some new buzzwords, or push a new paradigm, and thus have an excuse to keep blogging. However, I feel the best action is to value quality over bafflegab and just stop here.
The Every Computer Performance Book is the sum of what I had to pass on to the next generation and this blog contains a lot of what is in that book, plus a few extra goodies. I wrote the book to give back useful things that will always be true about performance work. I wrote the blog to help you find the book and for those that prefer their information in a digital form.
The blog entries are carefully tagged and categorized. If you just found this blog, I’d start at the first entry and read it forward.
I love to hear from my readers. If you care to write you can find me on the web, but know that above all, I love getting postcards and letters. If you are so moved, you can write to me at the address below. This is my high-fun, part-time, post-retirement job.
Bob Wescott – Tour Guide
c/o Ben & Jerry’s Factory Tour
1281 Waterbury-Stowe Road
Waterbury, VT 05676
USA
My computer performance career was a grand adventure, but all good things must come to an end.
StarTrek: The Next Generation “All Good Things…” Series Finale, Final Scene
The Every Computer Performance Blog 
Congratulations Bob. Sad to see this come to an end. We were thoroughly enjoying your posts…:). Best wishes and we might just drop in someday to sample the ice-cream at Ben and Jerrys…:)
Cheers,
Trevor
Practical Performance Analyst
I’ve always found your performance blog educational and entertaining. Your wealth of experience and insight has helped me tremendously in my career. I hope you find the time to continue sharing your adventures. Best regards. PS: I will eventually take the Ben and Jerry Factory Tour some day!
Thank you so much Bob. The book is, although its seriousness topic, a very pleasure to read and was and will always be a useful source of inspiration & understanding. Hope you will have a great time and wish you all the best.
cheers,
Uli Schäfer
Technical Project Manager
Thanks so much Bob!
It would be awesome if I could send my copy to you for an autograph.
I enjoyed reading your book and equally enjoyed re-reading sections in your blog. Thanks for leading The Next Generation… “Engage!”
Sad to read this post, as im starting to read your book.
Will be in touch. Thank you Bob.
Thanks,
Srinivas
Don’t know where else to send this, but if you’re taking errata on your book, I have this one:
In “Confidence in a Small Sample” you write “If the confidence intervals overlap, there is no statistically significant improvement.” This is a common misconception; you can in fact have overlapping confidence intervals and still have a statistically significant difference. To see why this is so, imagine that the intervals overlap just a bit. The probability of this happening if both means are actually the same is about 2 * (alpha/2) * (alpha/2) = alpha*alpha/2 — much smaller than your confidence level alpha. (The factor of two comes in because there are two possibilities for which of the sample means comes in low.)
The right way to tell if a difference is statistically significant is compute the confidence interval for the DIFFERENCE in the means, and check that it doesn’t overlap 0. Here’s one web page that describes how to compute that confidence interval:
http://www.kean.edu/~fosborne/bstat/06b2means.html
Kevin. That is a very important mistake you’ve found. Thank you! I looked at your blog and it is clear you have more stat skills that I do, so may I ask you this: I meant to say: “If the confidence intervals DON’T overlap, there is no statistically significant improvement” Is that a correct statement?