ACT Science: Strategies & Key Concepts

What are the three primary types of passages found in the ACT Science section?

Data Representation (graphs/tables), Research Summaries (experiments), and Conflicting Viewpoints (alternative hypotheses).

In a scientific experiment, what is the definition of an independent variable?

The variable that is intentionally changed or manipulated by the researcher to observe its effect.

Which axis on a standard line graph typically represents the dependent variable?

The vertical y-axis.

What does a 'direct relationship' between two variables signify in a data set?

A relationship where both variables increase together or decrease together.

What is the primary purpose of a control group in an experimental design?

To provide a baseline for comparison to ensure that the observed effects are due to the independent variable.

In an ACT Science table, what do the column headers usually represent?

The variables, categories, or units of measurement being tracked in the study.

What is the difference between interpolation and extrapolation when reading a graph?

Interpolation is estimating a value within the known data points, while extrapolation is predicting a value outside the data range.

What is the most effective strategy for approaching a Conflicting Viewpoints passage?

Identify the core disagreement between the scientists or students and note which evidence each uses to support their claim.

If a graph shows a line sloping downward from left to right, what type of relationship is indicated?

An inverse or negative relationship, where one variable increases as the other decreases.

What is a 'controlled variable' (or constant) and why is it necessary?

A factor kept the same across all experimental groups to ensure that only the independent variable affects the outcome.