ACT Science: Data Representation

The ACT Science test will contain 7 passages and 40 questions. The passages fall into three categories: Data Representation, Research Summaries and Conflicting Viewpoints. Many students find the Science test to be challenging because of the unfamiliar terminology and the variety of ways information is presented so don’t feel like you’re the only one! Let’s focus first on understanding how data is represented on the test.
The Data Representation format will ask you to understand and interpret information presented to you in graphs or tables. Occasionally there will also be charts, scatterplots, and diagrams. You’ll be able to recognize a Science passage as Data Representation if it does not contain multiple experiments or discuss multiple points of view. If you see a bunch of graphs and tables, you can bet it’s Data Representation! Often a scientific process will be explained (such as photosynthesis or osmosis).
While you may not be familiar with the process the passage discusses, the good news is that all of the information you will need to answer the questions will be located in the data. In a way, the Science mumbo-jumbo is the least important aspect of the test – all we want to do is have a fairly strong grasp of what is being presented. Here are a few tips to make sense of it all:

  • Locate the label (or label it yourself!)

    When you come across a table or a graph, read all of the labels. What is this chart called? If there is no label, or it is generic (such as “Table 1” or “Figure 1”), go back to the paragraph and see how the table or figure is described and then write a title yourself above the table/graph. Always locate the label for each set of data as you go. This will help you later figure out where to refer back for the correct answer.

  • Find out what the axes/columns/rows represent

    Just like we located the label for the entire table, you will also need to read and understand each part of the data. Don’t let an eagerness to get to those questions prevent you from reading the fine-print first! What is on the x-axis? What is on the y-axis? What is the label for each row and column? What are the individual parts of the diagram? You can’t skip the small stuff and feel free to underline and circle to your heart’s content. Anything that helps you remember is useful!

  • Note the units of measurement

    If heat is a variable, is it in Fahrenheit or Celsius? Is the mass in grams, kilograms, pounds? It may sound silly, but this can help you answer questions quickly and correctly later on! Check to see if there are little asterisks (*) at the bottom of the table or graph. They can offer some important supplemental information, so make sure to read those too!

  • Note the overall trends in the data

    Once you know the labels and the units of measurement for each item in the table/graph, it’s important to spend a few seconds thinking critically about the data. If Column A for example is increasing, what is Column B doing? Does it also increase, or does it decrease? Does it decrease for awhile and then level off? Create your own system of labeling that makes sense to you. Some students draw arrows, some triangles, and some simply underline or circle the points where data changes. The idea is to notice the changes since the ACT Science Test commonly asks questions about the relationship between two sets of data. Two common relationships are direct variations and indirect variations.


    Direction variation is when two things change in the same way over time. If Column A increases and Column B increases at the same time, we can say that the two vary directly. However, if when Column A increases, Column B decreases, there is an indirect variation (also called inverse) between the two.

It may seem like this will take you a long time, but making sure you have a strong understanding of the data will save you lots of headache when you read the questions. Even if the graphs and tables are confusing to you and seem intimidating, make sure you discipline yourself to read all of the words first. Don’t skip something just because you don’t understand the terms. The questions will be so much easier if you spend just a few minutes focusing on the data. Start practicing these tips with some Data Representation passages at home and you’ll be amazed at how quickly you’ll know where to look for the right answer!