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CDF Statistics Committee: What does it do?. Louis Lyons Oxford + SLAC March 2007. CDF Statistics Committee. Who? Luc Demortier, Rockefeller (chair) John Conway, UC Davis Joel Heinrich, Pennsylvania Tom Junk, Illinois Louis Lyons, Oxford Giovanni Punzi, Pisa Where?
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CDF Statistics Committee: What does it do? Louis Lyons Oxford + SLAC March 2007
CDF Statistics Committee Who? Luc Demortier, Rockefeller (chair) John Conway, UC Davis Joel Heinrich, Pennsylvania Tom Junk, Illinois Louis Lyons, Oxford Giovanni Punzi, Pisa Where? http://www-cdf.fnal.gov/physics/statistics/ When? Once a month since 2000
ACTIVITIES Frequently asked questions Recommendations Liasons Notes on statistical issues Links to Conferences, papers etc List of books
Frequently asked questions Estimating efficiencies near 1 Pull quantities Error on ratio of Poisson counts Unbinned maximum likelihood as goodness of fit? Combining quantities with unknown correlation Parametrising background shapes for fits Significance calculation allowing for background uncertainties Significance from difference in log(L) Combining significances from different (independent) analyses
RECOMMENDATIONS Neural networks, support vector machines Optimising searches Likelihood fits with individual event errors (Punzi effect) Coverage for Poisson intervals e.g. ΔlnL = -0.5 Plotting Poisson error bars Good and bad random number generators Systematics and limits: the Manhattan project Bayes and Frequentism Comparing 2 hypotheses Simple facts about p-values Blind analyses
Conclusions Useful for :-- Giving advice Spotting some errors Aiming for uniform practice Answering queries Possible improvements :-- More active liasons Someone at Fermilab to discuss, rather than e-mail More on multi-variate methods for separating signal from bgd More software