Joseph King

Unregistered less info
reputation
2
bio website location age member for 1 year, 1 month seen Apr 15 '12 at 14:44 profile views 5

9 Actions

 Apr15 comment Critical appraisal of survival paperSorry yes paper is not open access. I have pdf but I think not write to post it. Paper said "cumulative hazard assumption was tested by Schoenfeld residuals and by testing the time-dependent coefficients", so not critical this, but not known if parametric relative survive is better ? Think bias from missing data, but I must appraize survival model in primary for essay in 1500 words +/- 10%. Now have 200 words, so it problem is for me. Apr15 asked Critical appraisal of survival paper Apr11 awarded Scholar Apr11 accepted Sample size calculation for truncated normal distribution Apr10 comment Sample size calculation for truncated normal distributionthank you again. So I can use 0.0287 as SD in standard power calculation ? With example of following R code to detect 0.01 difference from control to intervention group ? power.t.test(delta = 0.01, sd = 0.0287 , sig.level = 0.05 , power = 0.9 , type = "two.sample", alternative = "two.sided") thank you more Apr10 comment Sample size calculation for truncated normal distribution@whuber thank you. So for my case I can take mean=1.65 and SD=0.0675 (which is SD of adult female height known from previous study) and use power.t.test with delta = 0.01, sd = 0.0675, sig.level = 0.05, power = 0.9, type = "two.sample", alternative = "two.sided", or I need to find SD of difference betwen height of adult females ? Apr10 awarded Student Apr10 comment Sample size calculation for truncated normal distributionThank you @andrea . I mention t-test because that is what I do /if/ the sample is normal distribution. I would like to make a calculation using truncation distribution, or I also think uniform distribution is good in this case because sample near the mean of the population and range is small. Can I make sample size calculation with truncated normal distribution or uniform distribution ? I prefer calculation instead of the simulation. Please to know your further comment, and also to confirm the central limit theorem is wrong to use for here. Apr10 asked Sample size calculation for truncated normal distribution