TEAS scientific reasoning questions: variables, experiments, and measurement
Written and reviewed by Rebecca Moore, MSN, RN, CEN · 3 min read · Updated October 2026
Short answer
Scientific reasoning is 9 of the 50 TEAS Science questions. ATI's topics are using basic scientific measurements and tools, applying logic and evidence to an explanation, predicting relationships between events and processes, and interpreting an investigation with the scientific method. It rewards careful reading more than memorising, so practise reading a setup slowly.
The four skills ATI lists
The first is measurement: knowing which tool measures what, such as a graduated cylinder for liquid volume, a balance for mass, and a thermometer for temperature, and reading a scale to the right precision. Metric units matter here too.
The other three are about thinking like an investigator. Apply logic and evidence means deciding whether a conclusion follows from the data. Predict relationships means saying what should happen next if a pattern holds. Apply the scientific method means reading a described experiment and identifying its parts.
Variables, controls, and the vocabulary of experiments
The independent variable is what the investigator changes on purpose. The dependent variable is what gets measured in response. Controlled variables are kept the same so they cannot explain the result, and a control group gets no treatment so there is something to compare against.
A hypothesis is a testable prediction, not a guess, and a good one can be shown wrong. Repeating trials and getting consistent results is about reliability; whether the experiment measures what it claims to measure is validity. These pairs are easy to swap under time, so learn them precisely.
Correlation is another favourite. Two things rising together does not show that one causes the other, and a question may offer a causal conclusion that the data cannot support.
How to work a reasoning question
Before you look at the answer options, name the independent and dependent variables in the setup. Then ask what the question actually wants: a prediction, a flaw in the design, or the conclusion the data supports. Many wrong options are true statements that answer a different question.
When a graph or table is involved, read the axis labels and units first, then the trend, then the question. A line that rises from left to right shows the dependent variable increasing as the independent variable increases, which is often all a prediction question needs. Our free TEAS science practice questions include scientific reasoning items with explanations that name the variable or flaw each one turns on.
Common questions
How many scientific reasoning questions are on the TEAS?
ATI lists 9 scientific reasoning questions in the Science section of TEAS Version 7.
What is the difference between an independent and a dependent variable?
The independent variable is what the investigator changes. The dependent variable is what is measured to see the effect of that change.
Do I need to memorise facts for TEAS scientific reasoning?
Very few. Know the measurement tools, metric units, and experiment vocabulary; the rest is reading the setup carefully and judging what the evidence supports.