Data Collection Bar graphs become meaningful to third-graders when they collect data themselves. One simple way to do this is to have students vote. Ask a question, such as favorite ice cream flavor or how kids get home from school. Each student casts a vote for one of the answer options. You can also have students create their own problems and collect data on their own. A child might decide to make a bar graph on hair color in the classroom, for example. He would list his color options and count the number of kids in the class that fit into each color option. This lesson helps students understand where the numbers come from on a bar graph.