Ideally, prior distributions would accurately represent beliefs about the likely values of branch lengths and other model parameters before the data are analyzed, giving posterior probabilities a subjective meaning that is more than arbitrary.
Therefore, before the data is analyzed, the response (R) must be normalized as a function of the maximum hemolysis (Rmax) that can be achieved.
Before the data were analyzed for this review, the methodological quality of the studies included after screening has been assessed, using a predefined checklist (Additional file 2 – Checklist).
In this example, the data for ozone and emergency department visits are "misaligned," and before the data can be analyzed, a surface (kriging) for ozone from the site data must be developed so that an ozone level can be estimated for each ZIP code.
The data were analyzed before and after manually reconfirming any peak with a coefficient of variation (CV) of >40% (48 pairs, 96 total metabolites); this procedure is referred to as "polishing" in Table 1, and was done specifically to determine if the analytical error originated before or during the HPLC analysis or during peak matching and quantitation.
Before describing how practically the data were analyzed, this section summarizes the authors' background to better locate their standpoint in the analysis process.
My biggest concern with all this is the post-Vioxx hysteria of not letting the data be analyzed carefully before its in the public domain, says Sam M. Cohen, a professor of pathology at the University of Nebraska Medical Center.
This analytic strategy was not prespecified but was developed before the data presented here were analyzed.
