Independent Variable: In a study investigating the impact of different teaching methods (e.g., traditional, online, and blended) on student performance, the independent variable would be the type of teaching method, as it’s the factor being manipulated to assess its effect on student performance.
Extraneous Variable: In the same study, an extraneous variable could be the students’ prior knowledge or their baseline academic performance, as this could influence their learning outcomes but is not the main focus of the research. This variable might affect the dependent variable (student performance) but is not part of the experimental manipulation.