ATAR Scientific Inquiry & Understanding 5 — Questions and Answers
Question 1: A scientist publishes a study showing that a new drug reduces symptoms. Another team attempts to replicate the study but gets different results. The best next step is to:
- Accept the original study since it was published first
- Discard both studies as unreliable
- Conduct further independent investigations to determine which result is more robust (Correct answer)
- Combine both datasets and average the outcomes
Correct answer: Conduct further independent investigations to determine which result is more robust
Replication failure triggers further investigation; multiple independent studies are needed to establish reliable scientific knowledge.
Question 2: In an experiment measuring reaction time, using a sample of only three participants would be problematic because:
- Three participants take too long to test
- The small sample size reduces statistical power and increases the effect of individual variation (Correct answer)
- Reaction time cannot be measured with fewer than ten people
- Three participants cannot provide qualitative data
Correct answer: The small sample size reduces statistical power and increases the effect of individual variation
Small sample sizes make results highly susceptible to individual variation and reduce the ability to detect true effects.
Question 3: Which scale of measurement is used when data can be ranked but the intervals between values are not equal?
- Nominal scale
- Ordinal scale (Correct answer)
- Interval scale
- Ratio scale
Correct answer: Ordinal scale
An ordinal scale allows ranking (e.g., 1st, 2nd, 3rd) but does not assume equal spacing between ranks.
Question 4: When a scientist states a result with a 95% confidence interval, it means:
- The experiment was successful 95% of the time
- There is a 95% probability that the true population value lies within the stated range (Correct answer)
- 95% of participants agreed with the result
- The scientist is 95% sure the hypothesis is correct
Correct answer: There is a 95% probability that the true population value lies within the stated range
A 95% confidence interval is a range within which the true population parameter is expected to fall in 95% of repeated samples.
Question 5: A student measures pH using universal indicator paper and records readings to two decimal places. This is problematic because:
- Universal indicator paper can only be read by specialists
- The precision of the recorded values exceeds the actual resolution of the measurement method (Correct answer)
- Two decimal places are never appropriate for pH measurements
- The student should have used a digital pH meter instead of paper
Correct answer: The precision of the recorded values exceeds the actual resolution of the measurement method
Recording more decimal places than the instrument's resolution implies a false level of precision that the method cannot support.
Question 6: Which of the following is an example of an inference rather than an observation?
- The solution turned blue when the indicator was added
- The mass of the solid was 12.4 grams
- The reaction must have released heat because the beaker felt warm (Correct answer)
- Three bubbles were produced per second
Correct answer: The reaction must have released heat because the beaker felt warm
An inference is a conclusion drawn from observations; stating the reaction released heat is a conclusion, while warmth is the observation.
Question 7: Which of the following correctly describes the relationship between a theory and a law in science?
- A theory becomes a law once it is widely accepted
- A law describes what happens; a theory explains why it happens (Correct answer)
- A law is always more reliable than a theory
- Theories are opinions while laws are proven facts
Correct answer: A law describes what happens; a theory explains why it happens
Scientific laws describe observable patterns or relationships, while theories provide explanatory frameworks for why those patterns occur.
ATAR Scientific Inquiry & Understanding 5
A scientist publishes a study showing that a new drug reduces symptoms.
Another team attempts to replicate the study but gets different results.
The best next step is to: