In an experiment, the independent variable is the factor the investigator changes, the dependent variable is the outcome that is measured, and controlled variables are kept the same so they cannot explain the result. The control group provides a baseline for comparison. A supported conclusion stays within the data and claims nothing beyond what was tested.
What are the parts of an experiment?
Independent variable: the factor the investigator changes on purpose.
Dependent variable: the outcome that is measured.
Controlled variables (constants): factors kept the same in every group.
Control group: the baseline condition the other groups are compared with.
Hypothesis: a testable prediction, often "If…, then…".
Which conclusion do the data support?
A supported conclusion describes the pattern in the data and stays within the conditions tested. Watch for choices that generalise to every setting, predict far beyond the tested range (extrapolation), or treat an association as proof of cause and effect.
How the lab works
Each round generates an invented experiment with a small data table.
Questions cover the independent and dependent variables, controlled variables (select all that apply), the control group, the hypothesis, reading the table and the supported conclusion.
Practice mode explains every option. Exam mode scores select-all items all or nothing, with no partial credit.
Questions and answers
What is the difference between independent and dependent variables? The independent variable is what the investigator deliberately changes, such as the amount of fertilizer. The dependent variable is the outcome measured to see whether it responds, such as plant mass. A quick check: the dependent variable depends on the independent one.
What is a control group? The group that provides the baseline for comparison, often the group that does not receive the change being tested or receives a standard condition. The experimental groups are compared with it. A control group helps, but on its own it does not prove a conclusion.
What is a controlled variable? A factor kept the same in every group, such as pot size, water or temperature, so that it cannot explain differences in the results. If two factors change at once, their effects are confounded and you cannot tell which one caused the result.
What makes a good hypothesis? A testable prediction about how the dependent variable will respond to the independent variable, often written as "If…, then…". A question, an opinion or a description of the method is not a hypothesis. Data can support a hypothesis or fail to support it.
How do I choose the conclusion the data support? Pick the statement that describes what the table or graph shows and stays within the conditions tested. Reject choices that claim the result holds everywhere, predict far outside the tested range, or describe a pattern the data do not show.
How many scientific reasoning questions are on the TEAS 7? ATI's content table lists 9 scored Scientific Reasoning items out of 44 scored Science items. These cover measurement, evidence, relationships in data and the design of investigations.
Sample questions with explanations
A researcher grows algae in identical tanks under red, blue or white light and measures the number of algae cells per milliliter after one week. What is the dependent variable? Answer: C. The number of algae cells per milliliter. The cell count is the outcome being measured, so it is the dependent variable. The light color is changed on purpose (independent variable), and the tank size and study length are held constant (controlled variables).
In an invented data set, towns that sold more ice cream in a month also reported more sunburns. Which conclusion is best supported? Answer: C. The two increase together, but these data alone do not show that one causes the other.. The data show an association: both rise together. A third factor, such as hot sunny weather, could drive both. Without a controlled comparison, the data cannot establish cause and effect, and they clearly are related, so D is wrong too.
TEASPATH is independent of ATI. Lab scenarios, data and questions are original practice material, not real TEAS items. Practice results are not official scores or admission predictions.
Independence
TEASPATH is independent of ATI. ATI TEAS® and TEAS® are registered trademarks of Assessment Technologies Institute, L.L.C., which is not affiliated with and does not endorse TEASPATH. Practice results are not official scores or admission predictions.