1. Section 3: Communicating with Graphs

2.  A graph is a visual display of information or data.  Scientists use graphs to display results of their experiments.  Graphs make data easy to compare

3.  Line graphs show change over time; the data are related.  A line graph can show more than one event on the same graph.  ALWAYS use the x-axis for the independent variable; y-axis for the dependent variable.  Make sure all the data use the same units.

4.  Bar graphs are useful for comparing data collected by counting.  The data are not related, as it is in a line graph, so the bars do not touch.

5.  A circle graph, or pie graph, is used to show how a certain quantity is broken down into parts.  The circle represents the whole and the segments, or slices, are the parts of the whole.  The segments are usually represented as percentages of the whole.