Page 15 - Doctoral Academy Level 1 Programme-2023

TOPIC 12

Sample size and power calculation – when and how to apply formulas

Purpose: The purpose of this presentation is to provide postgraduate students and early career
researchers with an understanding of sample size and power calculation, and when and how to apply

formulas to their research. By the end of the presentation, participants should have a clear understanding
of the importance of sample size and power calculation, and how to apply appropriate formulas to their
research.

Learning Outcomes: By the end of this presentation, participants should be able to:

1. Define sample size and power calculation, and explain their importance in ensuring the
reliability and validity of research findings.
2. Discuss the different factors that affect sample size and power calculation, including effect size,

type I and type II errors, and alpha and beta values.
3. Describe the different types of study designs and how they impact sample size and power

calculation, including cross-sectional, case-control, cohort, and randomized controlled trials.
4. Demonstrate an understanding of the importance of identifying the research question and aim
before applying sample size and power calculation formulas.

5. Demonstrate an understanding of the different types of formulas for sample size and power
calculation, including formulae for mean difference, proportions, correlation, and survival
analysis.

6. Discuss the importance of assumptions in sample size and power calculation, including normal
distribution, equal variance, and random sampling.
7. Demonstrate an understanding of the importance of statistical software in applying sample size

and power calculation formulas.
8. Apply appropriate sample size and power calculation formulas to their research, and critically

reflect on the implications of these formulas for research design and interpretation.

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