extraneous variable
nounUK /ɪkˈstreɪniəs ˈveəriəbl/
US /ɪkˈstreɪniəs ˈveriəbl/
A thing in a test that is not supposed to be there and might change the result.
The noise outside was an extraneous variable that made it hard to hear the answers.
OTHER MEANINGS
2. An extra factor in a study that researchers try to keep out.
Scientists controlled the temperature to remove an extraneous variable.
3. Something unrelated that sneaks into a situation and affects it.
A rainy day was an extraneous variable in their outdoor game.
4. A hidden influence that can confuse the results of a test.
The extraneous variable of tiredness made the scores less reliable.