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

Date:

26/09/2024

Organised by:

Statistical Services Centre Ltd

Presenter:

James Gallagher and Sandro Leidi

Level:

Intermediate (some prior knowledge)

Contact:

James Gallagher
07873873617
jamesgallagher1929@gmail.com

video conference logo

Venue: Online

Description:

Overview of 1-day course

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.

Cost

£258 (inclusive of 20% VAT)

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, so one presenter is always available to provide additional support. 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.

Cost:

£258

Website and registration:

Region:

International

Keywords:

Quantitative Data Handling and Data Analysis, Statistical Theory and Methods of Inference, Power analysis, Sample size, type 1 error, type 2 error, false positive, false negative, significance level, t-test, z-test, paired t-test, McNemar test, unequal allocation.

Related publications and presentations:

Quantitative Data Handling and Data Analysis
Statistical Theory and Methods of Inference
Power analysis

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