Scientific questions and observations

Correct answer: A. Whether non-responders differed from the remaining group

If non-responders differed from others the remaining sample may be biased. Examine the reason for missing data.

Correct answer: B. Average increase in height per day

Average height increase per day is a quantitative measure of growth rate. Relate change to time when measuring a rate.

Correct answer: A. Position may affect the measured sound level

Direct answer: A, position may affect the measured sound level. Sound travels through space, and the reading can change with the instrument’s distance, direction, height, nearby walls, and obstacles. Therefore, if the position changes on different days, a different reading may be caused by position rather than a real change in sound. Step by step: keep the same instrument, place it at the same distance and direction, and then compare readings. A is correct because position can affect sound reaching the sensor. B is wrong because sound level can be measured. C is wrong because the day may matter, but changing position is the stated problem. D is wrong because position changes readings, not merely colour. Memory cue: fair comparison means change one factor and keep the others constant.

Correct answer: B. Use a safe wafting method under teacher supervision

Unknown chemicals should not be smelled directly and safety instructions must be followed. Identify safe observation methods.

Correct answer: A. Predefine the primary outcome and record other outcomes separately

A predefined primary outcome reduces selective reporting. Set outcome criteria before data collection.

Correct answer: A. Keep a standard rapid-recording form ready

A prepared form helps record important time location and measurements immediately. Recognise planning for unexpected observations.

Correct answer: B. Number of correct responses on a standard task

Correct responses on a standard task provide a measurable indicator of concentration. Choose operational measures for abstract concepts.

Correct answer: A. Size-based observation bias

Missing small species will underestimate diversity. Examine detection ability and selection bias.

Correct answer: A. Measure at approximately the same time each day

Time of day affects temperature so measurement time should be consistent. Identify time as a controlled variable.

Correct answer: A. How does the number of migratory birds in an area change with seasons?

Seasonal migration patterns are best studied through long-term natural observation. Choose the method suited to the question.

Correct answer: A. Lack of measurement standardisation

The direct answer is A: lack of measurement standardisation. Standardisation means using the same clearly defined procedure each time. For plant height, choose one reference point, such as the soil surface or the base of the stem, keep the plant upright, use the same ruler and units, and measure in the same way. If the starting point changes, one reading may include more or less of the stem than another. The apparent difference may therefore be caused by the measuring method, not real growth. Option A is correct because the observations cannot be compared fairly without a fixed reference point. Option B is wrong because inconsistent measuring does not itself stop plant growth. Option C is wrong because height remains a numerical, quantitative measurement. Option D is wrong because the number of plants or observations does not automatically increase. Memory cue: same object, same starting point, same method, same units.

Correct answer: A. Confirmation bias

Recording only supportive observations weakens objectivity. Treat recording all outcomes as essential.

Correct answer: A. Measure and record its mass using a suitable balance

Very heavy is subjective while measured mass is objective. Convert descriptions into numbers and units.

Correct answer: A. Standardised observation across many sites and a long period

Rare events require greater sampling across time and space. Understand how observation effort affects detection.

Correct answer: A. Harmonise categories and definitions

Different definitions may assign different meanings to similar terms. Standardise before combining data.

Correct answer: B. How does the amount of salt affect melting time for equal masses of ice?

This question keeps ice mass equal while measuring salt amount and melting time. Identify elements of a fair test.

Correct answer: A. The terms are value-based and vague

Value-based terms may mean different things to different observers. Use clear behavioural indicators.

Correct answer: A. Define measurable variables related to the phenomenon and proposed cause

A causal test cannot be systematic without clear variables. Build a measurement plan from the question.

Correct answer: A. Hide group identity where possible

Concealing group identity can reduce observer bias. Understand the purpose of blinded observation.

Correct answer: B. Check the measurement and conditions and document the cause

An unusual value may reflect either an error or a real event. Investigate and document before excluding it.

Correct answer: A. How does airborne dust count vary across different parts of the school campus?

Air pollution may vary by location so sampling sites must be specified. Identify location-based variables.

Correct answer: A. Calibrate and compare both instruments

Changing instruments may introduce artificial differences. Check equivalence when instruments are replaced.

Correct answer: A. State both outcomes clearly and separately

The direct answer is A: state both outcomes clearly and separately. Scientific reporting must represent the observations honestly, even when the results move in opposite directions. “Opposite directions” does not automatically mean that one result is wrong. It may show that the tested factor has different effects on different outcomes, or that the situation is more complex than expected. Step by step: identify both measured outcomes; record the direction of change for each; compare them without hiding either one; then write a conclusion that describes both findings and avoids claiming more than the evidence supports. Option A is correct because it is complete, transparent, and objective. Option B is wrong because selecting only a preferred result introduces bias and conceals evidence. Option C is wrong because averaging unlike outcomes can destroy useful information and cannot honestly hide a real difference. Option D is wrong because an unusual result should not be called an error without checking the method, measurements, and repeated trials. Memory cue: report what was measured, not what you hoped to find. A balanced conclusion may say that one outcome increased while the other decreased.

Correct answer: A. Record rainfall amount and insect count in equal areas over several weeks

Measuring both variables over time allows their relationship to be examined. Look for adequate duration and equal sampling area.

Correct answer: A. Questions guide what evidence is recorded while observations generate new questions and revisions

In scientific inquiry questions and observations continually refine one another. Understand this as an evidence-based inquiry cycle.