If you run an experiment and find a difference between your groups, can you confidently say your treatment caused it? That is exactly the question internal validity answers. It is one of the most important ideas in research design, and examiners love asking about it — because a study with weak internal validity can look …
Causal Inference: Understanding Cause-and-Effect Relationships Causal inference is a key concept in research that focuses on determining whether a cause-and-effect relationship exists between variables. In many scientific fields, especially in psychology, medicine, social sciences, and economics, understanding causality is crucial for drawing meaningful conclusions from research. While correlation shows a relationship between two variables, causal …