Scientific Method Quiz
Questions: 16 · 10 minutes
1. Which statement is an observation rather than an inference?
The heating system must have switched on recently.
The room became warmer because sunlight entered the window.
The thermometer reads 22.4°C.
People in the room probably feel comfortable.
2. An independent research team follows a published experimental procedure and obtains a similar result. What does this most directly demonstrate?
Replication
Peer review
Instrument calibration
Random sampling
3. Two groups of identical seedlings receive different fertilizers, but one group is kept in a warmer room. Why is this a problem?
The experiment does not include a dependent variable.
Fertilizer cannot be studied using an experiment.
Room temperature is a confounding variable that could also affect growth.
Both groups must receive every fertilizer being tested.
4. Students test whether water temperature changes how quickly sugar dissolves. They record the time required for one teaspoon of sugar to disappear. What is the dependent variable?
The temperature of the water
The type of cup used in every trial
The amount of sugar added to each cup
The time required for the sugar to dissolve
5. A student wants to test whether daily light exposure affects bean plant growth. Which is the strongest testable hypothesis?
Bean plants receiving eight hours of light daily will grow taller over three weeks than plants receiving four hours, under otherwise identical conditions.
Light is important to plants because they need it to live.
Healthy bean plants probably prefer the most natural lighting conditions.
Bean plants grow differently for many reasons, including light and soil.
6. Ice cream sales and sunburn cases both increase during summer. What conclusion is justified by this correlation alone?
Eating ice cream directly increases the chance of sunburn.
Sunburn causes people to purchase more ice cream.
A third factor, such as hot sunny weather, may influence both variables.
The relationship proves that one of the two variables causes the other.
7. A student measures a pendulum's period only once. What would best reduce the influence of accidental timing error?
Use the measured value without rounding it
Repeat the measurement several times and calculate the average
Compare the value with an unrelated experiment
Replace the hypothesis after seeing the value
8. Which statement gives an operational definition of plant growth for an experiment?
Plant growth occurs when environmental conditions are favorable.
Plant growth is the change in stem height, measured in centimeters over 14 days.
Plants that receive nutrients should grow better than other plants.
Growth is one of the most important features of living organisms.
9. A scientist tests whether a new disinfectant reduces bacterial growth on laboratory surfaces. Which group is the most appropriate control?
Surfaces treated with twice the recommended disinfectant dose
Surfaces measured only after bacterial growth becomes visible
Comparable surfaces treated in the same way but without the new disinfectant
Different surfaces cleaned with the new disinfectant at different times
10. Which claim is falsifiable and therefore suitable for scientific testing?
An undetectable force changes results whenever anyone tries to measure it.
Under the same pressure, adding a specified amount of salt changes water's measured boiling point.
A lucky object improves outcomes in ways no observation can reveal.
Nature produces certain patterns because it prefers harmony.
11. In a controlled experiment, what is the main purpose of randomly assigning participants to groups?
To reduce systematic preexisting differences between the groups
To guarantee that every participant responds to the treatment
To ensure that the sample perfectly represents the entire population
To let participants select the condition they consider most suitable
12. What is a central purpose of peer review in science?
To ensure that reviewers agree with the study's original hypothesis
To prove that published findings can never later be revised
To replace the need for other researchers to replicate the study
To let qualified researchers evaluate a study's methods, reasoning, and reporting before publication
13. An experiment produces reliable results that do not support the original hypothesis. What is the most scientifically appropriate response?
Discard the results because successful experiments confirm hypotheses.
Repeat only the trials that came closest to the predicted result.
Treat the hypothesis as correct until another researcher objects.
Report the results and revise or reject the hypothesis as warranted.
14. A student releases identical toy cars from the same ramp onto three surfaces and repeats each condition five times. Cars consistently stop sooner on the roughest surface. Which conclusion is best supported?
Under the tested conditions, the roughest surface was associated with the shortest stopping distance.
The ramp angle had no possible influence on any result.
Rough surfaces always stop every moving object more quickly.
Surface texture is the only factor that can affect a toy car's stopping distance.
15. A researcher gives tomato plants different amounts of fertilizer and measures the number of tomatoes produced. What is the independent variable?
The number of tomatoes produced
The amount of fertilizer given
The type of tomato plant used
The length of the growing period
16. A researcher records the temperature of a liquid every minute for 30 minutes. Which graph is generally most suitable for displaying the change over time?
A pie chart showing each temperature as part of a whole
A bar graph with the measurement order omitted
A table listing only the highest and lowest temperatures
A line graph with time on the horizontal axis and temperature on the vertical axis