Variables and controls
Mon, Apr 12, 2027 · Week 13 · Human Anatomy & Physiology (Human Body Systems)
Today's goal: Students will define independent, dependent, and controlled variables using teacher notes and the PLTW online task.
What a finished product looks like
This is a model of the work you should turn in today. Use it to check your own: match the structure and the level of detail, do not copy it. Your data and wording should be your own.
Sample experiment: Testing whether a low dose of copper in the water changes how fast C. elegans worms move.
- Independent variable (what I change): the amount of copper added to the water (0, low, medium).
- Dependent variable (what I measure): the worms' movement speed (body bends per minute).
- Controlled variables (held constant): temperature, food amount, age of the worms, dish size, observation time.
Confounding variable example: if the copper dishes were also kept warmer than the control dishes, then temperature would be confounded with copper, and I could not tell whether slower movement came from the copper or the heat.
Also due today: Submit your labeled experiment to the Schoology assignment for HBS Research Model Day 2.
WebXam problem for today's skill
One exam-style question that uses exactly what you practiced today. Try it before you reveal the answer, then read why each choice is right or wrong.
Tap an answer to see the full explanation. Nothing is recorded or graded.