Why is experimental design important?

Good experimental design is important in all research, it helps to ensure the data collection, data analysis and conclusions from a study, are valid (true). Good experimental design is essential in research and fundamental to scientific progress. Research projects are written up into ‘papers’ which are submitted for publication in peer-reviewed scientific journals. These papers are cited and used to inform future research should be as accurate as possible, ensuring the studies are robustly designed, conducted and reported is therefore essential. 

Sadly, there are examples of poorly designed research published in even the most respected scientific journals, despite systems of review designed to avoid this. Where research does not have a robust design, it can lead to bias in the results or poor data/statistical analyses leading to incorrect conclusions. These research outcomes are misleading and can render the research of little value.  

At Replacing Animal Research we advocate for good experimental design and believe that good science across all experiments, animal and non-animal, is vital to helping reduce and ultimately replace animal research. 

Historically, under our previous name of Fund for the Replacement of Animals in Medical Experiments (FRAME) in the 90s and 00s the charity supported experimental design training to ‘reduce’ as well as ‘replace’ of animal use. Scientists who require a licence for regulated animal research in the UK must abide by something known as the 3Rs principles, the first is to avoid or ‘replace’ animal use and the second is to ‘reduce’ animals numbers to a minimum. When scientists are trained in experimental design particularly where there is a likelihood of using animals,  they must be taught about how to find replacements, but also how to reduce animal use though experimental design.

Our work today focusses solely on ‘Replacement’ and helping scientists find and use alternatives to animals.

Animal use in research can be reduced through experimental design 

Experimental design is key to all scientific research, and all those conducting research should have a solid understanding of the basics of planning a study and how to avoid bias. This starts in primary school and should continue through postgraduate study. There is room for more to be done through education and training to ensure future researchers have the knowledge and skills to correctly plan any research study, including animal studies. Whilst animal research is still happening, and we are working to reduce reliance on animals in research good experimental design is important for several reasons:  

• It ensures studies using modern, non-animal approaches are planned and conducted correctly to help build the evidence base for new approaches to research questions, increase confidence in them and lead to greater uptake and advancement where animals may still be used.
• It ensures that where animals are used in research studies the 3Rs including the replacement and reduction of animal use are correctly implemented.
• Ensures animal’s lives are not wasted in poorly planned research which may then be repeated (using yet more animals).
• It builds up a reliable evidence base of areas of research where animal studies do not translate to humans. (For example, in areas of human disease research.

In regulated preclinical animal research, and indeed clinical research using patients, understanding experimental design is important for scientific reasons and helps avoid, for example, the common practice of focusing on one gender in a study to reduce variability in results due to sex, which is frequently highlighted as a poor scientific choice missing out vital differences between how different genders respond to drugs and disease. As well as scientific concerns, poor experimental design raises concerns around wasted money, time and resources when valuable funding is essentially wasted on the conducting and publication of poorly planned studies. The peer-review process should reduce the chance of this research being published, but this does not always work – see this article ‘Poorly designed animal experiments in the spotlight’.

The PREPARE Checklist (Planning Research and Experimental Procedures on Animals: Recommendations for Excellence) is a useful tool for researchers to increase the reproducibility of research and testing using animals through correct implementation of the 3Rs and quality experimental design.