TEAS Science: How to Understand Scientific Reasoning and Experiments
Science questions do not always ask you to remember a definition. Some require you to interpret an experiment, identify a variable, compare results, or determine whether a conclusion is supported by the evidence. Learning how scientific investigations work can help you approach these questions systematically.
1. Understand the purpose of a hypothesis
A hypothesis is a proposed explanation or prediction that can be investigated. A useful hypothesis is specific enough to guide an investigation. For example: Plants receiving more light will grow taller over a two-week period, provided other relevant conditions remain similar. This statement predicts a relationship that can be tested by collecting measurements. It does not guarantee that the prediction will be correct. When evaluating a hypothesis, ask what evidence could support or challenge it.
2. Identify the variables
Experiments often involve different types of variables. - Independent variable: The factor deliberately changed by the investigator. - Dependent variable: The outcome measured. - Controlled variables: Other conditions kept consistent when possible. In the plant example, the amount of light is the independent variable, and plant growth is the dependent variable. Factors such as plant type, soil, and water should be kept as consistent as possible. Identifying these variables helps you understand what an experiment is designed to test.
3. Understand control groups
A control group provides a comparison that helps researchers evaluate the effect of a treatment or change. For example, if one group of plants receives a new fertilizer and another comparable group does not, the second group may serve as a control. The exact design depends on the research question. Not every experiment uses the same type of control group, and a comparison group alone does not automatically eliminate every possible source of bias.
4. Read results carefully
Scientific data may be presented in tables, graphs, or written descriptions. Start by reading the title, labels, units, and any notes explaining the measurements. Then identify the pattern relevant to the question. If a graph shows that a measurement rises over time, you can describe that trend. You should not automatically conclude that the independent variable caused the increase unless the experimental design and evidence justify that conclusion. Correlation and causation are different concepts. Two measurements changing together does not, by itself, establish that one caused the other.
5. Distinguish results from conclusions
Results describe what was observed or measured. A conclusion explains what those results suggest about the original question. Suppose an experiment finds that plants receiving more light grew taller on average than plants receiving less light. The results may support the hypothesis, but you should also consider sample size, measurement quality, and whether other conditions were sufficiently controlled. A scientific conclusion should match the strength of the evidence rather than make a broader claim than the experiment allows.
6. Practise with short experiments
Read a short experiment description and identify its question, hypothesis, independent variable, dependent variable, and relevant controls. Then ask what conclusion the data supports and what additional evidence might be useful. Review incorrect answers by identifying whether you misunderstood a variable, misread a graph, or drew an unsupported conclusion.
Final thoughts
Scientific reasoning improves when you connect the research question to the experiment's design and results. Practise interpreting data, distinguishing correlation from causation, and selecting conclusions supported by evidence. Check the current ATI TEAS outline to confirm the scientific concepts relevant to your preparation.
