Introduction to Evidence

Analysing evidence is crucial for successfully navigating any complex or controversial topic. This section covers key topics in critically evaluating evidence, including an introduction to causation, inductive inference, an overview of some basic principles of statistics, and a discussion of some problems and limitations of statistical analysis that are important to be on the lookout for.

Causation and Evidence


Post hoc reasoning

Necessary and sufficient conditions


Anecdotal evidence

Types of evidence

Principles of Statistics


Sample and Population

Types of data

Measures of centre

Measures of spread

Statistical inference

Testing for group differences

Correlation and causation

Bayesian reasoning

Problems with Statistical Analyses

Biased sample

Small sample size

Confounding variables

Circular analysis

External validity

Interaction effects

Placebo effects


Academic Literature

Academic sources

Peer review

Review articles

Accessing academic journals

Additional Resources

Stanford Encyclopedia of Philosophy article on evidence: an excellent introduction to the philosophical issues of what evidence is and how it is used

Types of scientific evidence: simple discussion and graphic covering the different types of scientific evidence

Scientific ‘proof’, scientific evidence, and the scientific method: great introductory article from TalkOrigins in the context of analysing evolution

Making sense of statistics: an excellent resource explaining in an accessible manner how to critically interpret statistical evidence, from Sense about Science

Glossary of statistics: useful definitions of key words and concepts in statistics

Applied Statistics lecture notes: a set of clear and concise lecture notes for a course on applied statistics

Statistical reasoning: an introduction to some key concepts and approaches in statistical reasoning

Wikipedia page on misuse of statistics: a great introduction to the many potential pitfalls of statistical analyses

Statistics for the terrified glossary: this site provides a simple, non-mathematical introduction to many key concepts in statistics

Research methods knowledge base: a guide to many topics in research methods