English to Portuguese Tech/Engineering Mathematics & Statistics

Power Analysis for Survival Analysis, Exponential with Accrual & Dropouts (Power Calculation)
Example. These two options are best explained with an example. In an educational study of high school dropouts, for instance, it may happen that, overall, there are fewer dropouts than there are students who stay in school (i.e., there are different base rates); thus, the a priori probability that a student drops out is lower than that a student remains in school. The a priori probabilities can greatly affect the classification of cases or objects. If differential base rates are not of interest for the study, or if one knows that there are about an equal number of cases in each class, then one could set the a priori probabilities to be Equal. If the differential base rates are reflected in the class sizes (as they would be if the sample is a probability sample) then set the a priori probabilities to Estimated.