The one constant in a biological population is variability. It is very unlikely that two individuals will be identical in every way. We can see this demonstrated in this image of the participants at the 6th ITI Consensus Conference in Amsterdam. This group of individuals varies considerably across a wide range of criteria.
This variability between individuals is the basis of natural selection and evolution. Variability can influence many biological processes, including how patients will respond to disease, and how they might react to the treatments that we provide to them.
If we wish to determine if our treatments are effective, we need to consider how variation in the population might affect our results and whether the outcomes we detect are due to our interventions, or just the effects of blind chance.
Biostatistics is the body of knowledge that we can use to measure variability and describe the average individual, that is, to describe the central tendency of the population. By statistically comparing these features of two or more groups of individuals, we can help determine the root cause of the effects that we observe.
After completing this ITI Academy Module, you should be able to…
describe the source and effects of natural variation in biological populations
describe measures of variability and central tendency
define a null hypothesis and describe the means of testing statistically significant differences
recognize potential problems in the interpretation of study results in published literature