What Sample Size Do I Need? with R
​(online course)

Overview
Choosing an appropriate sample size is a common problem and should be given due consideration in any research proposal, as an inadequate sample size invariably leads to wasted resources. Hence objective sample size determination is increasingly requested by regulatory authorities in a number of disciplines. 
This course aims to give a practical introduction to sample size determination, or power calculations, in the context of some commonly used hypothesis tests. Examples from a scientific background will be used to highlight the problems associated with sample size determination, and suggest potential solutions. Practical work will be based around the free statistical software R; see https://www.r-project.org/. Formulae and algebraic notation will be kept to a minimum.

​Presenters
Sandro Leidi and James Gallagher

Delivery Mode
All training is online and will be delivered live between 09:00 and 17:30 (GMT+1).  The delivery platform is Zoom, which may be freely accessed.  Questions may be asked using Zoom's chat box.  Note our online courses are delivered by a team of two presenters, meaning at least one presenter is always available to provide additional support.  During presentations, the team member who is not speaking can take questions in addition to the presenter.  We also use Zoom meetings rather than webinars to encourage further interaction during an online course.

Who Should Attend?
Scientists and related who need to address the problem of sample size determination or power calculations in planning a study. Participants will be assumed to have a working knowledge of sampling distributions, confidence intervals and hypothesis tests for both means and proportions.  
No previous experience of the R software is required.

How You Will Benefit
This course will give you a sound introduction to sample size determination, and be able to conduct common power calculations using the free R software. 

What Do We Cover?
  • Concepts of significance and power in relation to hypothesis tests
  • Sample size determination (power calculations) with one sample, two samples and paired samples for comparing means with a t-test
  • Sample size determination (power calculations) with one sample, two samples and paired samples for comparing proportions with a z-test
  • Practical problems associated with sample size determination and possible solutions
  • Other issues such as the role of confidence intervals and why it can be difficult to determine sample size.
The course will make use of our R functions which will be made freely available.

Software
Practical work will be done in R.
Note:
  • For practical work, participants must download and install the R software.  This must be done prior to the start of the course
  • Practical work is based on the Windows operating system.
Course Dates
25 September 2025

Venue: Online
Duration: 1 day
Price: £270

Apply Now
(terms and conditions apply)

Return to full course listing
Vertical Divider