Follow this module to learn about optimizing your experimental design
After completing it, you should be able to:
- Explain the difference between exploratory and confirmatory research
- Formulate a well-defined hypothesis for a confirmatory interventional study
- Name different types of formal experimental designs and explain their advantages and disadvantages
- Choose the most appropriate study design for your planned study
- Identify the experimental unit and recognize issues of non-independence
- Perform a sample size calculation for a study with a parallel group design
Core materials
Material 1 – Replication
Study this material to learn about:
- What replicability means
- What “within experiment replication” and “between experiment replication” are
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 2 – Pseudo-replication
Study this material to learn about:
- What pseudo-replication is
- How to recognize pseudo-replication and/or sources of pseudo-replication
- How to avoid it
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 3 – Hypothesis
Study this material to learn about:
- Formulating a proper hypothesis for the appropriate study type (hypothesis generating or confirmatory)
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 4 – Block design
Study this material to learn about:
- How a block design can be implemented on different levels in order to prevent unwanted variation and/or reduce bias
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 5 – Factorial design
Study this material to learn about:
- How to use a factorial design in order to study possible interaction between two variables
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 6 – Recruitment
Study this material to learn about:
- The concept of external validity and why it is important
- How recruitment plays a role in external validity
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 7 – Negative controls
Study this material to learn about:
- The importance of negative controls, why they are necessary, understand how to choose appropriate negative controls
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 8 – Positive controls
Study this material to learn about:
- The importance of positive controls, why they are necessary, understand how to choose appropriate positive controls
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 9 – Calibration
Study this material to learn about:
- The importance of using calibrated and validated instruments to accuracy and precision of measurements
- Ways in which instruments can be calibrated and validated
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 10 – Precision and accuracy
Study this material to learn about:
- The difference between accuracy and precision
- Methods to measure accuracy and precision
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 11 – Intra-observer reliability
Study this material to learn about:
- The concept of intra-observer reliability
- How intra-observer variability affects accuracy and precision of your outcome measurement
- Measures you can take to reduce these effects
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 12 – Baseline assessment
Study this material to learn about:
- When and what kind of baseline assessments to perform
Type: knowledge clip
Duration: 5 minutes
Created by: Healthcare triage
Material 13 – Biological and Technical replicates
Study this material to learn about:
- The difference between biological and technical replicates
Type: knowledge clip and discussion material
Duration: 2 minutes + 30 minutes discussion
Created by: National Institute of Health
Bonus materials
Bonus 1 – Group housing
Study this material to learn about:
- The risks and (statistical) consequences of group housing
Type: knowledge clip
Duration: 3 minutes
Created by: Stats in the Lab
Additional resources
- Website: 3rs-reduction.co.uk – interactive short course on experimental design for scientists working with laboratory animals
- Lecture series: Let’s Experiment : A Guide for Scientists Working at the Bench – 6 week course by iBiology, on understanding the principles of experimental design (protocol, bias, logbooks, interpretation)
- Tool: NC3Rs Experimental Design Assistant (EDA) – free online tool to guide researchers through the design of their in vivo animal experiments
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