ANATOMY OF A LINE CHART Line Charts are used to present data trends over time. They may present a single variable or be used to compare multiple variables over time. Building a Line Chart: 1) Draw the horizontal & vertical borders. 2) Place category labels (the variable’s values; e.g. specific years) and the variable name (e.g. Years) on the horizontal axis. 3) Label the y-axis (count, freq., percent) and insert the scale being used (e.g. 0% – 14% ). 4) Above each year place a dot representing the count or percent recorded for that year. 5) Connect the dots. 6) Add a title describing the chart’s contents. Horizontal Gridlines, which help visually interpret the counts or percentages, may also be added. Chart Title. The line connects the values recorded for each time period (here year). The y-axis presents the value (%, $, count) of the variable being presented. The x-axis displays the time variable (days, years, etc.). Line Chart comparing two variables.