Read the following hypothesis.
H1H_1H1: "Year 12 students who revise A-level Psychology content using spaced-repetition software for 30 minutes daily will achieve significantly higher recall scores on a timed vocabulary test than Year 12 students who revise using standard reading and highlighting of textbooks for 30 minutes daily."
What is the independent variable (IV) in this hypothesis?
The recall score achieved on a timed vocabulary test
Whether students are in Year 11 or Year 12
Using spaced-repetition software or standard reading and highlighting of textbooks for revision
The daily revision duration, restricted to 30 minutes
