RICAS Scientific Inquiry 3 — Questions and Answers
Question 1: A student conducts the same experiment five times and gets very different results each time. What does this most likely indicate?
- The hypothesis was incorrect
- The experiment lacks proper controls
- There is too much variability, possibly due to uncontrolled variables (Correct answer)
- The student should average all results and move on
Correct answer: There is too much variability, possibly due to uncontrolled variables
Highly variable results across trials usually signal that one or more variables were not adequately controlled.
Question 2: In an experiment testing whether fertilizer affects tomato plant growth, what is the dependent variable?
- The type of fertilizer used
- The amount of water given to each plant
- The growth of the tomato plants (Correct answer)
- The type of soil used
Correct answer: The growth of the tomato plants
The dependent variable is what is measured in response to changes in the independent variable—in this case, plant growth.
Question 3: Which of the following best describes a scientific theory?
- A guess about what might happen in an experiment
- A well-tested explanation supported by a large body of evidence (Correct answer)
- A single experiment that proves a fact
- An idea that has never been questioned
Correct answer: A well-tested explanation supported by a large body of evidence
A scientific theory is a well-substantiated explanation of some aspect of the natural world, supported by repeated testing and evidence.
Question 4: A student records data in a table showing the time (in minutes) it takes ice to melt at different room temperatures. Which is the independent variable?
- Time for ice to melt
- Mass of the ice cube
- Room temperature (Correct answer)
- Brand of thermometer used
Correct answer: Room temperature
The independent variable is the one deliberately changed by the experimenter—here, the room temperature.
Question 5: Why is it important to use SI (metric) units when recording scientific data?
- Metric units are easier to memorize than customary units
- Using standard units allows scientists worldwide to compare and replicate results (Correct answer)
- The RICAS test requires metric units only
- Metric units are always more precise than customary units
Correct answer: Using standard units allows scientists worldwide to compare and replicate results
Standard units ensure that measurements are consistent and can be understood and reproduced by scientists anywhere in the world.
Question 6: A scientist publishes results claiming a new diet pill causes weight loss. Other scientists try to reproduce the results but cannot. What does this suggest?
- The original results were definitely fabricated
- Reproducibility problems raise doubt about the original findings (Correct answer)
- The other scientists used incorrect methods
- The pill's effectiveness depends on location
Correct answer: Reproducibility problems raise doubt about the original findings
Reproducibility is a cornerstone of science; if others cannot replicate results, the original findings are considered unreliable until confirmed.
Question 7: Which of the following is the best way to reduce measurement error in an experiment?
- Use only one trial to save time
- Average the results of multiple trials (Correct answer)
- Round all measurements to the nearest whole number
- Remove data points that seem unusual
Correct answer: Average the results of multiple trials
Averaging multiple trials reduces the impact of random errors and gives a more reliable estimate of the true value.
RICAS Scientific Inquiry 3
A student conducts the same experiment five times and gets very different results each time.
What does this most likely indicate?