Graphs + Charts

A good way to explore is to start seeking examples of graphs and charts in your everyday life. Check at the library in research books. Find the weather report in the newspaper. Look online for statistic sites. Take a few pictures of different kinds of charts. Looking critically, which ones seem easy to read? Which ones present information more quickly than a written paragraph? Which ones appear graphically vibrant? By looking at other charts and reflecting on their design, you are developing a visual library of examples that you can compare and contrast.
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A concise communication of information starts with a title that summarizes what data you are showing. It lists the source or sources of the amounts that you are sharing. Your sources might include people you surveyed, organizations you research, individuals who contributed information. A key or legend reveals what the chart or graph is communicating. Is it data about children? Is it the average weight of cattle? Is it the range of life expectancies of different countries. Excluding pie charts, most graphs use an x and y-axis. The y-axis runs vertically The x-axis runs horizontally and can be divided into whatever increments you choose- pounds, minutes, years, months, etc. Most importantly, charts and graphs work to communicate information so that people can understand information easily. Make a list of the types of charts that you want to learn!

A pie chart is a circular shape, resembling a ‘real pie,’ divided into pieces. Think of cutting up a pizza. You can split it in half, thirds, quarters, etc.. Pie charts are used to communicate parts of a whole. The measure of the sections is most often in fractions and percentages. Make a pie chart that shows the activities you participate in during one school day. First, calculate the minutes you are in school. Next, make a list of all of your activities. Be sure to include lunch, recess, and all of your subjects. Now record the number of minutes you spend in each activity. Use this equation for each activity: x/100= number of minutes of one activity /over the number of total minutes of your school day. Your result is each activity being a percentage of the whole time. You can color code and label your time. You can make a chart of how you spend your 24-hour day! Is it easy to read? Does it reveal anything surprising? Is it the same as your parents or grandparents?

Bar charts use ‘bars’ to compare different things. For instance, if one mother dog has a litter of puppies, you can represent the number of male vs. female puppies, or use different rows to show the number of black, brown, white and tri-colored puppies! Bar charts run horizontally or vertically and can be two dimensional or three dimensional. Different sets of data can be shown side by side or stacked in single bars. Bar charts can also communicate change over time. A good example is a temperature record of a city listing the average temperature per month over one year. Make a bar chart of the temperature range month by month of your community. You can use blue to represent precipitation. You can even add a yellow to a gray bar that shows percentages of sunny vs. overcast days per month.

Area Graphs are like line graphs, but instead of using lines they use zones to represent different categories. For example, the information might be grouped by ages- 0-12, 13-18, 18-24, 25-35, etc. Area graphs look like high mountain ranges as they show amounts. They also can show changes over time. For instance, in the hospital, they might register your average heart rate over your time spent in the hospital. Make an area graph of demographics of the people living in your city.

This type of chart helps visualize interactions between two different things. It might be a pitcher’s throw and the arc of his or her arm and the speed of the ball. Point charts or x-y plots communicate and determine and speculate on the relationships between chosen categories. The x and y-axis represent variables of different topics and events.

Variables are important to graphs and charts as they can be plotted to inform our understandings and even our decisions. Variables can be many things but should be defined. They can be whatever you choose- a measure, amount of light, the intensity of sound, excitement, time periods, etc. You are in charge of your charts! There are two types of variables- independent, and dependent. An independent variable is constant. It does not change by other variables. On the other hand, a dependent variable is affected by other factors. Usually, when you make a chart to visualize information, you are looking to see what makes the dependent variable change.

Learning to read graphs and data sets is a skill of deciphering the parts to understand the whole. It helps to break the reading of the chart or graph into three parts: Identify (what you see) Interpret (what each part means) Caption the Meaning(describe what is revealed). First, look at the parts of the graph. Perhaps you see dates, or amounts, or other measurements in the x or y-axis. Notate changes that you see. In step two, interpret what these changes mean. In step 3, move each what you see statement to what it means and create a synopsis of the information. Try to begin a short caption paragraph with a topic sentence of what the graph shows. Use the following sentences to note each of the things you observed and how they contribute to the topic of the graph. Finally, end with a concluding sentence that summarizes your findings!

• Independent variables
  • are unchanging
  • change dependent variables
• Bar charts can be
  • 2 dimensional
  • 3 dimensional
  • show different colored bars for different subjects
  • all of the above
• Charts and Graphs communicate information.
  • true
  • false
• Line graphs show
  • changes over time vertically
  • changes over time horizontally
• Which chart divides a circle?
  • area chart
  • pie chart
  • point chart
  • x-y plot