How to Read Graphs/Charts, Tables, or Timelines


In Social Studies you will encounter information (from sources) that is presented in graphs/charts, tables, and timelines. Graphs/charts, tables, and timelines are meant to provide information and data, visually represent the information and data, and reinforce written information. Often, graphs/charts, tables, and timelines will be accompanied by statistics (a collection and analysis of large numbers). Statistics are also crucial pieces of information that help us understand our world.

Learning how to read graphs/charts, tables, and timelines can help support your understanding of what you read in print.  But graphs/charts, tables, and timelines can also reinforce points in a presentation, and can help you develop insight into how our world is changing and growing. We can often make better sense of numbers when they appear in visual forms. Graphs/charts, tables, or timelines can make trends apparent and illustrate clearly changes, differences, and inequalities.

Guidelines for Reading Graphs/Charts, Tables, and Timelines in Social Studies 

Click on the tabs below to review some tips on how to read graphs/charts, tables, and timelines in Social Studies.

  • A graph or chart is a visual representation of a relationship, usually between two variables. The values representing one variable are plotted on a horizontal (x) axis, and the values representing another variable are plotted on a vertical Yes axis. Usually the y-axis values depend on the x-axis values. As such, the independent variable values are plotted on the horizontal (x-axis), and the dependent variable values are plotted on the vertical axis (y-axis).
  • Graphs/charts allow viewers to see data and predict future trends (extrapolate). A graph or chart can take a variety of forms: pie chart, bar graph/chart, or line graph/chart.
  1. Look at the title of the graph/chart and any accompanying information such as captions, or italics around the graph/chart. This can help you determine what is being represented.
  2. Depending on the type of graph/chart, there may be information on the x-axis (horizontal) and y-axis (vertical). This information is important to see how the data values are related.
  3. Colours may be important; in a pie chart, the amount and type of colour gives meaning to the data.
  4. Numbers and written text can accompany the graph/chart. This additional information can help clarify what is being presented.
Pie Chart
Bar Graph/Chart
Line Graph/Chart
Analysis: The above pie chart shows US Federal Spending in 2016, measured in billions of dollars (we can see that from the title). Each of the coloured pie wedges shows how many billions of dollars are spent and in which area, as well as what percentage (%) of the pie (all monies) is spent on that area.
Analysis: The above bar graph/chart shows the types of voters and their education levels during the 2008 US Presidential Election (title). On the x-axis (horizontal) the education levels of the voters are shown, and on the y-axis (vertical) the percent of people over 18 who have that level of education are shown.
Analysis: The line graph/chart shows life expectancy at birth in various regions of the world from 1950-2050, according to the United Nations (title). The x-axis (horizontal) shows time (in years), and the y-axis (vertical) life expectancy. Each coloured line indicates a different region measuring.

  • A table is an arrangement of data in rows and columns.
  • There is one type of data in the rows and another type of data in the columns. There can be multiple rows and multiple columns, depending on how much data there is to display.
  1. Look at the title of the table, as well as the title of the data in the rows and columns. This will tell you about the information offered in the table.
  2. Read the top of the column, and then each of the corresponding row. Do this for the whole table. What you should see is a comparison of information as you move across the table.
  3. While many of the tables' data will be numbers, sometimes table creators will include images for emphasis.
Analysis: The table above shows column data by year, % of the urban population, and % of the rural population in the US Census. The urban and rural populations were measured between the years 1900-1990. The purpose of the table is to compare the percentage of people in urban centres versus rural areas in the United States in the years indicated.
Analysis: The table above has multiple rows and columns of data. Firstly, the table shows Canada's immigrant population in 2006, including country of origin and when (year period) they immigrated to Canada. In the far left column, countries of origin are listed, and the next column to the right shows the total numbers from that country of origin in 2006. The columns to the right are titled "Period of Immigration", which breaks down the immigrant populations by when (what year period) they immigrated to Canada.


  • A timeline is a visual representation of time as a line. It is usually presented in chronological order (from beginning to end), with dates and years
  • A timeline can often help us understand history, especially when there are multiple events or major groups involved.
  1. Read the title of the timeline to determine what is being represented. What are the time periods (years, days, dynasties, eras)?
  2. Read left to right, or top to bottom. What are the major events or groups highlighted?
  3. If there are unequal distances in the measurement of time, this could indicate how much time has passed.
Analysis: The timeline above displays Canadian History (title). It should be read from left to right. The main timeline shows time period (years), starting at the year 1000. There is information above and below the timeline, indicating major events within that time period.
Analysis: The timeline above shows the major events in World War II (title). The time (years) is indicated on the left, and the major events within each year are listed to the right of the timeline.



Misuse of graphs/charts, tables, and timelines


"It pays to be wide awake in studying any graph. The thing looks so simple, so frank, and so appealing that the careless are easily fooled."

M J Moroney


You should also understand how graphs/charts, tables and timelines can be used to mislead people.

  • Exaggerating or compressing the scale: Sometimes, to convince the viewer, there can be an exaggeration or compression of the scale(s) on the graph. The figures can show the same data, but can suggest an alarming trend of  increase or decrease by not beginning at zero and showing the intervals as large as possible.

  • No scale provided: Frequently,  drug companies attempt to push their drugs into the market by sharing positive-looking graphs with no scale. The appearance of the graph may make a drug look incredibly effective, but without a scale it is impossible to make an informed decision. One must always be careful when interpreting graphs and charts without scales. Also, be wary when a scale is given without units.

  • The graph is based on insufficient data: Graphs may show great-looking trends, but if there is no mention of sample size, it is difficult to draw accurate conclusions. What if only 10 people were given a new drug on a trial basis? Would you feel comfortable taking the medication based on the results?

  • Too much data: When graphs and charts have too much information, they confuse the reader. If an overwhelming amount of information is provided, nothing is learned.