Comments on: All your bias are belong to us http://hea-www.harvard.edu/AstroStat/slog/2007/astroph-07054199/ Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders Fri, 01 Jun 2012 18:47:52 +0000 hourly 1 http://wordpress.org/?v=3.4 By: hlee http://hea-www.harvard.edu/AstroStat/slog/2007/astroph-07054199/comment-page-1/#comment-20 hlee Tue, 05 Jun 2007 15:28:27 +0000 http://hea-www.harvard.edu/AstroStat/slog/2007/astroph-07054199/#comment-20 1. All Chi-sq methods I've seen from astronomy literature (only a few, though) assume central Chi-sq dist'n. I wonder if there are works using non-central Chi-sq dist'n (considering your best fit minimizes variance but it's biased). 2. Above question leads these questions: how do I estimate bias? or make it asymptotically unbiased? or as you mentioned, average properly (model averaging is studied in statistics by both frequentists and bayesians)? or is non-central Chi-sq suitable? 3. I don't have any answers. People of different paradigms have various answers and opinions, and I like to learn. 1. All Chi-sq methods I’ve seen from astronomy literature (only a few, though) assume central Chi-sq dist’n. I wonder if there are works using non-central Chi-sq dist’n (considering your best fit minimizes variance but it’s biased).

2. Above question leads these questions: how do I estimate bias? or make it asymptotically unbiased? or as you mentioned, average properly (model averaging is studied in statistics by both frequentists and bayesians)? or is non-central Chi-sq suitable?

3. I don’t have any answers. People of different paradigms have various answers and opinions, and I like to learn.

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