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| = Adding 0.5 to cells when calculating d' and the empirical logit transform = '''On the use of the +0.5 smoothing for calculating the empirical logit transform see:''' |
= Adding 0.5 to cells when calculating odds ratios, d' and the empirical logit transform = == On the use of adding 0.5 to cells to define an odds ratio == Subbiah and Srinivasan (2008) note the practice of adding a constant to a zero cell to define an odds ratio. They go on to state "Usually a continuity correction, by addition of 0.5, is considered for studies with zero counts in the estimation of the log of the odds ratio or the log of the risk ratio." * M Subbiah and M R Srinivasan (2008) Classification of 2x2 sparse data sets with zero cells. ''Statistics & Probability Letters'' '''78(18)''' 3212-3215. A pdf copy of this paper is available to read and print from [[http://www.sciencedirect.com/science/article/pii/S0167715208003003|here.]] == On the use of the +0.5 smoothing for calculating the empirical logit transform see: == |
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| '''On the use of the +0.5 smoothing for calculating the d' signal detection parameter see:''' | == On the use of the +0.5 smoothing for calculating the d' signal detection parameter see: == |
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| [Last updated on 27 November, 2003] | == See also == [[FAQ/sigdet|Signal Detection Parameters from SPSS]] There a different convention is followed of putting ''1/2N'' and ''1-1/2N'' in place of ''0%'' and ''100%''. and [[https://sites.google.com/a/mtu.edu/whynotaprime/ | here which suggests a nonparametric alternative to ROC curves which represents an average over all possible ROC curves]]. |
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| [wiki:FAQ Return to Statistics FAQ page] | |
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| [http://www.mrc-cbu.cam.ac.uk/Statistics/index.shtml Return to Statistics main page] | These pages are maintained by [[mailto:ian.nimmo-smith@mrc-cbu.cam.ac.uk|Ian Nimmo-Smith]] and [[mailto:peter.watson@mrc-cbu.cam.ac.uk|Peter Watson]] |
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| [http://www.mrc-cbu.cam.ac.uk/ Return to CBU main page] These pages are maintained by [mailto:ian.nimmo-smith@mrc-cbu.cam.ac.uk Ian Nimmo-Smith] and [mailto:peter.watson@mrc-cbu.cam.ac.uk Peter Watson] |
~- Last updated on 27 July, 2006 -~ |
Adding 0.5 to cells when calculating odds ratios, d' and the empirical logit transform
On the use of adding 0.5 to cells to define an odds ratio
- Subbiah and Srinivasan (2008) note the practice of adding a constant to a zero cell to define an odds ratio. They go on to state "Usually a continuity correction, by addition of 0.5, is considered for studies with zero counts in the estimation of the log of the odds ratio or the log of the risk ratio."
M Subbiah and M R Srinivasan (2008) Classification of 2x2 sparse data sets with zero cells. Statistics & Probability Letters 78(18) 3212-3215.
A pdf copy of this paper is available to read and print from here.
On the use of the +0.5 smoothing for calculating the empirical logit transform see:
David R COX and E J SNELL (1989) Analysis of Binary Data , Chapman and Hall: London
On the use of the +0.5 smoothing for calculating the d' signal detection parameter see:
Michael J HAUTUS (1995) Corrections for extreme proportions and their biasing effects on estimated values in d'. Behavioral Research Methods, Instruments, & Computers, 27(1), 46-51.
See also
Signal Detection Parameters from SPSS There a different convention is followed of putting 1/2N and 1-1/2N in place of 0% and 100%.
These pages are maintained by Ian Nimmo-Smith and Peter Watson
Last updated on 27 July, 2006