4. Calculating In Terms of ‘Difference to Detect’ & Power From Sample Size

Introduction to Sample Size Calculation Training session with Dr Helen Brown, Senior Statistician, at The Roslin Institute, January 2016. ************************************************ These training sessions were given to staff and research students at the Roslin Institute. The material is also used for the Animal Biosciences MSc course taught at the Institute. ************************************************ A spreadsheet to carry out the calculations described in the presentation may be copied here: http://datashare.is.ed.ac.uk/handle/1... ********************************************* *Recommended YouTube playback settings for the best viewing experience: 1080p HD ************************************************ Content: Relationship between sample size , power and detectable difference Find out what sample size would be needed in terms of size of difference detectable Power calculation: Find out power of studies with varying sample sizes and effect differences Calculate power for varying numbers of mice and effect differences -Power calculation --- Sometimes sample size calculation is described as ‘power calculation’ or ‘power analysis’ The power of a study can also be calculated retrospectively --- can be useful to know if study is under-powered when interpreting a non-significant result Find out size of difference detectable in RBC (?), based on varying sample sizes