Science Foundations

• Read and interpret line graphs, bar charts, scatter plots, and data tables
• Identify independent and dependent variables in experiments
• Recognize trends, direct relationships, and inverse relationships in data
• Extract specific data points from complex figures quickly
• Finish on one ACT-hard question and say what made it hard

ACT Science questions primarily test your ability to interpret data rather than recall scientific facts. Data Representation passages present graphs, tables, or figures and ask you to read values, identify trends, and make predictions. Work the figure before the questions: name the two variables (the axis labels, with units) and say which way the trend runs, then answer each question by going back to the figure, and eliminate any choice that contradicts the trend. To judge a relationship, test two or three points rather than going by how the curve looks: a smooth curve can hide values that double at each step, and a curve may look nearly straight over a short stretch. A direct (positive) relationship means both variables increase together; an inverse (negative) relationship means one increases while the other decreases. Beyond simple lookups, expect to interpolate and extrapolate (read a value between or beyond the plotted points), combine two figures (find X in Figure 1, then read the matching Y in Figure 2), and hold one variable constant while comparing another. First note: Science is now a separate optional section that does not change your 1-36 composite, so take it only if a target college requires or recommends it. If you are taking it, careful reading of axes and units turns many questions into reliable points, but treat the trickier multi-figure questions with respect. Two more facts: calculators are not allowed on the Science section, so any arithmetic is simple reading or estimating, and a few questions assume basic background from introductory science courses (for example, that density is mass divided by volume or that a pH below 7 is acidic). Harder figures: a graph with two vertical axes plots two variables against one horizontal axis, so read each curve against its own axis (the legend or the curve's label says which). When two displays share a variable, link them through it: find the shared value in the first display, then read the matching value in the second. At the hard end, the answer sits in the second of two linked displays, or a pattern that looks linear turns out to multiply rather than add.

• Read the axis labels and units before looking at the data. Many wrong answers simply switch units.
• Trace from the point on the graph straight across to the axis to read exact values, and sketch on scratch paper if two lines cross.
• Skip the long text at first, but not the figure: take about 15 seconds to name the variables and the trend, then go to the questions and return to the figure for each one.