A Step-by-step Example, From Question to Variables
A Step-by-step Example, From Question to Variables
Question
Does writing a one-line explanation after each math problem improve Grade 8 word-problem scores over six weeks?
Variables
IV: writing a one-line explanation. DV: weekly word-problem quiz score.
Constants
Textbook, teacher, time of day, problems per class, way problems are introduced.
A Step-by-step Example, From Question to Variables
A teacher of Grade 8 mathematics wants to study a new strategy. She suspects that asking students to write a one-line explanation of how they solved a problem will improve their understanding.
Research question
Does writing a one-line explanation after each math problem improve Grade 8 students’ performance on word problems over six weeks?
Variables in this study
Independent variable. Writing a one-line explanation after each math problem. This is the thing the teacher introduces. She controls when it is used. The design is within-subjects across weeks: some weeks the routine is in place, some weeks it is not, and all students experience both phases.
Dependent variable. Performance on word problems. This is what the teacher measures. The measurement is the score on a weekly five-question word-problem quiz, marked with a clear rubric.
What is kept constant
The textbook. The teacher. The time of day. The number of problems per class. The way problems are introduced. As many things as possible are kept the same so that any change in the dependent variable can be attributed to the independent variable.
What we expect to see
If the strategy works, the IV (writing the one-line explanation) changes, and the DV (word problem scores) changes in response. If the DV does not change, either the strategy did not work, or it needs more time, or something else (a confounding variable) interfered.
This shape (IV introduced, DV measured, everything else held constant) is the skeleton of every action research study.
Practice table
Use this layout when you write your own study. Filling all five columns forces you to be specific.
| Research question | Independent variable | Dependent variable | Measurement | Possible confounding variable |
|---|---|---|---|---|
| Does writing a one-line explanation after each math problem improve Grade 8 word-problem scores over six weeks? | Writing a one-line explanation after each problem | Word-problem score | Weekly five-question rubric-marked quiz | Student tiredness on quiz day |
| Does peer feedback improve Grade 8 essay introductions over four weeks? | Peer feedback on introductions, twice a week | Quality of essay introductions | Five-point rubric on the introduction paragraph | Whether peers were trained in giving feedback |
| Does daily silent reading improve Grade 6 comprehension over six weeks? | Ten minutes of silent reading at the start of every lesson | Comprehension score | Weekly chapter quiz | Students’ decoding skill at baseline |
A second card that names the move you make every time you turn a question into a study plan.
