What are the required dos and don'ts in calculating a sample size? What formula should be used and what should be avoided?
Muneed,
the exact formula depends on the statistical model you plan to use in your hypothesis tests.
Generally, you need:
- your predetermined alpha level (the probability of rejecting a true null hypothesis),
- your desired power level (the probability of rejecting a false null hypothesis),
- the effect size you want to be able to detect.
May this will help:
Article Sample Size Planning for Statistical Power and Accuracy in P...
Agree with Heiko.
It's all depends on situation I.e. your study design, sampling techniques, allocation ratio of cases and controls and so on.
Required things also depend on whether it is an estimation problem or comparison problem.
Go through this book , it's very nice.
Or describe your problem so that I can help further.
Thanks.
Hi Ravi, Thanks for the booklet you shared.
Can you suggest me a few points about sample size calculation in a prospective randomized single blind clinical trial?
as your question is very general , 3 days agoRavi Prakash Jha already add good points should be considered
as regard your second question of sample size in randomized trail, you should at first determine the primary outcome and categorize its variable type whether interval or qualitative variable and expected change in its value based on previous research or pilot study
For details of sample size calculation and sampling methods please see my presentation at research gate:
https://www.researchgate.net/profile/Abdel-Hady_El-Gilany/contributions
- Badges
- Science topic
- Similar topics
- Mathematics
- Statistics
- Sampling Design
- Sample Size