Scientific Inquiry, Investigation, and Processes of Science
This domain tests how elementary teachers design fair investigations, interpret evidence, and explain how scientific knowledge is built. Expect questions on variables, measurement, data displays, and the difference between observations and inferences.
Designing a fair test
- A testable question identifies a cause-and-effect relationship that can be investigated with evidence.
- The independent variable is what the investigator changes; the dependent variable is what is measured; controlled variables are held constant.
- A control group provides a baseline and receives no treatment or a standard treatment.
- Replication and adequate sample size reduce the influence of random error.
Evidence and measurement
- Observations are what you detect with senses or instruments; inferences are explanations based on observations.
- Quantitative data are numerical; qualitative data are descriptive.
- Precision describes how close repeated measurements are to one another; accuracy describes how close a measurement is to the true value.
- Use SI units and read scales at eye level; for water in a graduated cylinder, read the bottom of the meniscus.
Worked example
A student predicts that extra light increases bean seed germination. She places 10 seeds in a sunny window and 10 in a dark closet, waters all equally, and counts sprouts after 10 days. The independent variable is light exposure; the dependent variable is the number of germinated seeds; constants include water, soil, seed type, and time. The closet group is the control. If more seeds sprout in the window, the data support the prediction, but one trial is not proof; replication across trials strengthens the claim. Reasoning: a fair test changes only one variable and compares results against a baseline.
Traps that cost marks
- Calling a hypothesis a random guess; a hypothesis is a testable, evidence-based prediction.
- Confusing correlation with causation.
- Choosing a conclusion that the data do not support.
- Omitting units or reading the top of the meniscus.
- Treating a scientific theory as an unproven idea rather than a well-supported explanation.