paired or unpaired t-test We are polling respondents every month and asking a couple of questions about the number of times they eat certain foods.   We have significant loss to follow up every month but generally retain 20% - 30%.  For the participants who stay engaged and respond across the months, I understand we use the paired t-test.   My question is what test would be appropriate to use to compare between two months say for example comparing a june &amp; july sample which contains some folks in june who dropped out in july, some folks who answered for both june and july, and some new randomly selected folks who were added in july?   I've read through previous posts but cant get whether using the paired test is really appropriate. THANKS!
t-test for partially paired and partially unpaired data An investigator wishes to produce a combined analysis of several datasets.  In some datasets there are paired observations for treatment A and B.  In others there are unpaired A and/or B data.  I am looking for a reference for an adaptation of the t-test, or for a likelihood ratio test, for such partially paired data.  I am willing to (for now) to assume normality with equal variance and that the population means for A are the same for each study (and likewise for B).
Why should boostrap sample size equal the original sample size? When searching the internet on the sample size of for boostrap samples I generally find that the size should equal the original sample size. However, I can't find any explanation on why this should be the case.   In what way is it bad to use a smaller sample size? Is it always better to use a larger sample size?   Some of the sites which report this: