Unit Checkpoint
Overview
Test your mastery of the scientific method including experimental design, variable identification, data analysis, and CER writing.
Checkpoint Questions
Question 1: What makes a hypothesis testable?
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Answer: It can be supported or refuted through experimentation or observation; involves measurable variables
"Ghosts exist" isn't testable. "Plants grow taller with more light" is testable - you can measure it.
Question 2: In an experiment testing if caffeine affects heart rate, identify: independent variable, dependent variable, and one control.
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Answer: IV: caffeine amount; DV: heart rate; Controls: time of measurement, participant activity level, room temperature
The IV is manipulated, DV is measured, controls are kept constant.
Question 3: Why do scientists use large sample sizes?
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Answer: To reduce the impact of individual variation and increase reliability of results
One unusual result won't skew the data as much when sample size is large.
Question 4: What's the difference between qualitative and quantitative data?
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Answer: Quantitative = numerical/measured (15 cm, 23C); Qualitative = descriptive/observed (blue color, rough texture)
Both types are valuable; quantitative allows mathematical analysis while qualitative captures details numbers miss.
Question 5: An experiment shows correlation between ice cream sales and sunburns. Does ice cream cause sunburns?
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Answer: No - this is a correlation, not causation. Hot weather (lurking variable) causes both.
Correlation means two things happen together; causation means one makes the other happen.
Question 6: Write a complete CER for: Question - Does temperature affect how fast sugar dissolves?
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Answer: Claim: Higher temperature causes sugar to dissolve faster. Evidence: Sugar dissolved in 20 seconds at 60C, 45 seconds at 40C, and 90 seconds at 20C. Reasoning: Higher temperatures give water molecules more kinetic energy, allowing them to break apart sugar crystals more quickly.
Include specific data and explain the scientific principle connecting evidence to claim.
Question 7: Identify the error: "My hypothesis was wrong, so my experiment failed."
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Answer: Incorrect understanding - unsupported hypotheses are not failures; they're valuable findings
Experiments "fail" only when poorly designed. Learning what doesn't work is important scientific progress.
Question 8: Why must experiments be repeatable?
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Answer: To verify results; if others can't replicate findings, the original results may have been due to error or chance
Replication is fundamental to building reliable scientific knowledge.
Question 9: What should you do with unexpected results?
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Answer: Report them honestly, investigate possible causes, consider if they reveal something new, don't hide or change them
Unexpected results often lead to important discoveries. Scientific integrity requires honest reporting.
Question 10: How does the scientific method connect to SAT/ACT skills?
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Answer: Tests require analyzing experiments, interpreting data, evaluating claims, and understanding cause/effect - all scientific method skills
The ACT Science section directly tests these skills; SAT includes data interpretation across subjects.