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Apologies, where I wrote ?method = ?MN??, it should have been ?measure = ?MN??.
On 16/10/2017, 17:18, "Anne-Wil Kruijt" <mail at awkruijt.nl> wrote:
Dear all,
Thank you, professor Viechtbauer, for referring me to this list.
Delving into metafor?s mechanics I noticed that when ?method = ?MN? ? is specified in escalc(), its calculation of sampling variance (vi) is ?vi <- sdi^2/ni?. I wondered why there is no option to use the(/a?) unbiased estimator ?vi <- sdi^2/ni-1?. I?m considered to bypass the escalc step and ?manually? compute vi as sdi^2/ni-1 ? but I?m hesitant because it isn?t an option in escalc() (when method = ?MN?, i.e. when obtaining the ?raw mean difference? for input as yi). Does anyone have any insights to share on why it is or is not a good idea to use the ?unbiased estimator? in the context of a REML MA on raw mean difference values?
All best,
Anne-Wil