During this on-demand session tutor Dr Nikki Osborne discusses: * the 3V's (construct, internal and external validity), * what makes a good hypothesis, * the PREPARE guidelines, * what to think about before designing your experiments including systematic reviews, * sources of bias and how to minimise their impact on your research, * defining the experimental unit, * approaches to maximise the signal to noise ratio, plus calculating the correct sample size, * common sources of variation and how to take them into account in your experimental design, * ARRIVE 2.0 for reporting animal studies. * freely available tools and resources to support individuals to develop their knowledge, understanding and skills further.