UST Middle School Science Challenge
Week 1 — Scientific Thinking & Experimental Design
Grades 6–8 • Focus: Variables, controls, hypotheses, data and evidence
Weekly Format
Variables, controls, hypotheses, data and evidence
Part A — 15 Multiple Choice
Part B — 15 Fill in the Blank
Part C — 15 Scientific Reasoning / Open Response
Part D — 5 Challenge Problems
Answers and How to Solve are separated at the end.
Part A — Multiple Choice
Questions 1–5
1. In an experiment, the factor intentionally changed is the? A) independent variable B) temperature C) volume D) random chance
2. The group used for comparison is the? A) control group B) temperature C) volume D) random chance
3. A testable explanation is called a? A) hypothesis B) temperature C) volume D) random chance
4. Repeating trials mainly improves? A) reliability B) temperature C) volume D) random chance
5. A conclusion should be based primarily on? A) data B) temperature C) volume D) random chance
Part A — Multiple Choice
Questions 6–10
6. In an experiment, the factor intentionally changed is the? A) independent variable B) temperature C) volume D) random chance
7. The group used for comparison is the? A) control group B) temperature C) volume D) random chance
8. A testable explanation is called a? A) hypothesis B) temperature C) volume D) random chance
9. Repeating trials mainly improves? A) reliability B) temperature C) volume D) random chance
10. A conclusion should be based primarily on? A) data B) temperature C) volume D) random chance
Part A — Multiple Choice
Questions 11–15
11. In an experiment, the factor intentionally changed is the? A) independent variable B) temperature C) volume D) random chance
12. The group used for comparison is the? A) control group B) temperature C) volume D) random chance
13. A testable explanation is called a? A) hypothesis B) temperature C) volume D) random chance
14. Repeating trials mainly improves? A) reliability B) temperature C) volume D) random chance
15. A conclusion should be based primarily on? A) data B) temperature C) volume D) random chance
Part B — Fill in the Blank
Questions 16–20
16. Complete the statement: A testable explanation is called a ______.
17. Complete the statement: Repeating trials mainly improves ______.
18. Complete the statement: A conclusion should be based primarily on ______.
19. Complete the statement: In an experiment, the factor intentionally changed is the ______.
20. Complete the statement: The group used for comparison is the ______.
Part B — Fill in the Blank
Questions 21–25
21. Complete the statement: A testable explanation is called a ______.
22. Complete the statement: Repeating trials mainly improves ______.
23. Complete the statement: A conclusion should be based primarily on ______.
24. Complete the statement: In an experiment, the factor intentionally changed is the ______.
25. Complete the statement: The group used for comparison is the ______.
Part B — Fill in the Blank
Questions 26–30
26. Complete the statement: A testable explanation is called a ______.
27. Complete the statement: Repeating trials mainly improves ______.
28. Complete the statement: A conclusion should be based primarily on ______.
29. Complete the statement: In an experiment, the factor intentionally changed is the ______.
30. Complete the statement: The group used for comparison is the ______.
Part C — Scientific Reasoning
Questions 31–35
31. A student compares two conditions and records results over five trials. Explain how the idea “control group” is relevant. Use 2–3 complete sentences.
32. A class observes a model and explains how its parts work together. Explain how the idea “hypothesis” is relevant. Use 2–3 complete sentences.
33. Students examine a data table and notice a consistent pattern. Explain how the idea “reliability” is relevant. Use 2–3 complete sentences.
34. A team changes one factor and measures the response. Explain how the idea “data” is relevant. Use 2–3 complete sentences.
35. A scientist compares evidence from two possible explanations. Explain how the idea “independent variable” is relevant. Use 2–3 complete sentences.
Part C — Scientific Reasoning
Questions 36–40
36. A student compares two conditions and records results over five trials. Explain how the idea “control group” is relevant. Use 2–3 complete sentences.
37. A class observes a model and explains how its parts work together. Explain how the idea “hypothesis” is relevant. Use 2–3 complete sentences.
38. Students examine a data table and notice a consistent pattern. Explain how the idea “reliability” is relevant. Use 2–3 complete sentences.
39. A team changes one factor and measures the response. Explain how the idea “data” is relevant. Use 2–3 complete sentences.
40. A scientist compares evidence from two possible explanations. Explain how the idea “independent variable” is relevant. Use 2–3 complete sentences.
Part C — Scientific Reasoning
Questions 41–45
41. A student compares two conditions and records results over five trials. Explain how the idea “control group” is relevant. Use 2–3 complete sentences.
42. A class observes a model and explains how its parts work together. Explain how the idea “hypothesis” is relevant. Use 2–3 complete sentences.
43. Students examine a data table and notice a consistent pattern. Explain how the idea “reliability” is relevant. Use 2–3 complete sentences.
44. A team changes one factor and measures the response. Explain how the idea “data” is relevant. Use 2–3 complete sentences.
45. A scientist compares evidence from two possible explanations. Explain how the idea “independent variable” is relevant. Use 2–3 complete sentences.
Part D — Challenge
Questions 46–50
46. Challenge: Design or describe a short investigation that could demonstrate the concept “independent variable.” Identify what you would observe or measure.
47. Challenge: Design or describe a short investigation that could demonstrate the concept “control group.” Identify what you would observe or measure.
48. Challenge: Design or describe a short investigation that could demonstrate the concept “hypothesis.” Identify what you would observe or measure.
49. Challenge: Design or describe a short investigation that could demonstrate the concept “reliability.” Identify what you would observe or measure.
50. Challenge: Design or describe a short investigation that could demonstrate the concept “data.” Identify what you would observe or measure.
Answer Key — Questions 1–5
Answer + How to Solve
1. Answer: A
How to solve: The independent variable is deliberately changed by the investigator.
2. Answer: A
How to solve: A control provides a baseline for comparison.
3. Answer: A
How to solve: A hypothesis is a testable proposed explanation.
4. Answer: A
How to solve: Repeated trials reduce the effect of random variation.
5. Answer: A
How to solve: Scientific conclusions should follow the evidence collected.
Answer Key — Questions 6–10
Answer + How to Solve
6. Answer: A
How to solve: The independent variable is deliberately changed by the investigator.
7. Answer: A
How to solve: A control provides a baseline for comparison.
8. Answer: A
How to solve: A hypothesis is a testable proposed explanation.
9. Answer: A
How to solve: Repeated trials reduce the effect of random variation.
10. Answer: A
How to solve: Scientific conclusions should follow the evidence collected.
Answer Key — Questions 11–15
Answer + How to Solve
11. Answer: A
How to solve: The independent variable is deliberately changed by the investigator.
12. Answer: A
How to solve: A control provides a baseline for comparison.
13. Answer: A
How to solve: A hypothesis is a testable proposed explanation.
14. Answer: A
How to solve: Repeated trials reduce the effect of random variation.
15. Answer: A
How to solve: Scientific conclusions should follow the evidence collected.
Answer Key — Questions 16–20
Answer + How to Solve
16. Answer: hypothesis
How to solve: A hypothesis is a testable proposed explanation.
17. Answer: reliability
How to solve: Repeated trials reduce the effect of random variation.
18. Answer: data
How to solve: Scientific conclusions should follow the evidence collected.
19. Answer: independent variable
How to solve: The independent variable is deliberately changed by the investigator.
20. Answer: control group
How to solve: A control provides a baseline for comparison.
Answer Key — Questions 21–25
Answer + How to Solve
21. Answer: hypothesis
How to solve: A hypothesis is a testable proposed explanation.
22. Answer: reliability
How to solve: Repeated trials reduce the effect of random variation.
23. Answer: data
How to solve: Scientific conclusions should follow the evidence collected.
24. Answer: independent variable
How to solve: The independent variable is deliberately changed by the investigator.
25. Answer: control group
How to solve: A control provides a baseline for comparison.
Answer Key — Questions 26–30
Answer + How to Solve
26. Answer: hypothesis
How to solve: A hypothesis is a testable proposed explanation.
27. Answer: reliability
How to solve: Repeated trials reduce the effect of random variation.
28. Answer: data
How to solve: Scientific conclusions should follow the evidence collected.
29. Answer: independent variable
How to solve: The independent variable is deliberately changed by the investigator.
30. Answer: control group
How to solve: A control provides a baseline for comparison.
Answer Key — Questions 31–35
Answer + How to Solve
31. Answer: Response should correctly apply: control group.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. A control provides a baseline for comparison.
32. Answer: Response should correctly apply: hypothesis.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. A hypothesis is a testable proposed explanation.
33. Answer: Response should correctly apply: reliability.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. Repeated trials reduce the effect of random variation.
34. Answer: Response should correctly apply: data.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. Scientific conclusions should follow the evidence collected.
35. Answer: Response should correctly apply: independent variable.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. The independent variable is deliberately changed by the investigator.
Answer Key — Questions 36–40
Answer + How to Solve
36. Answer: Response should correctly apply: control group.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. A control provides a baseline for comparison.
37. Answer: Response should correctly apply: hypothesis.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. A hypothesis is a testable proposed explanation.
38. Answer: Response should correctly apply: reliability.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. Repeated trials reduce the effect of random variation.
39. Answer: Response should correctly apply: data.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. Scientific conclusions should follow the evidence collected.
40. Answer: Response should correctly apply: independent variable.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. The independent variable is deliberately changed by the investigator.
Answer Key — Questions 41–45
Answer + How to Solve
41. Answer: Response should correctly apply: control group.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. A control provides a baseline for comparison.
42. Answer: Response should correctly apply: hypothesis.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. A hypothesis is a testable proposed explanation.
43. Answer: Response should correctly apply: reliability.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. Repeated trials reduce the effect of random variation.
44. Answer: Response should correctly apply: data.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. Scientific conclusions should follow the evidence collected.
45. Answer: Response should correctly apply: independent variable.
How to solve: Define the concept, connect it to the scenario, and cite the observation or measurement that supports the connection. The independent variable is deliberately changed by the investigator.
Answer Key — Questions 46–50
Answer + How to Solve
46. Answer: Answers vary; investigation must correctly demonstrate independent variable.
How to solve: State a testable setup, identify the variable/measurement, predict an observable result, and explain why that result demonstrates the concept.
47. Answer: Answers vary; investigation must correctly demonstrate control group.
How to solve: State a testable setup, identify the variable/measurement, predict an observable result, and explain why that result demonstrates the concept.
48. Answer: Answers vary; investigation must correctly demonstrate hypothesis.
How to solve: State a testable setup, identify the variable/measurement, predict an observable result, and explain why that result demonstrates the concept.
49. Answer: Answers vary; investigation must correctly demonstrate reliability.
How to solve: State a testable setup, identify the variable/measurement, predict an observable result, and explain why that result demonstrates the concept.
50. Answer: Answers vary; investigation must correctly demonstrate data.
How to solve: State a testable setup, identify the variable/measurement, predict an observable result, and explain why that result demonstrates the concept.