Why Use Charts or Graphs:
A page full of numbers is very hard to understand. But if you put those
same numbers on the right kind of chart, they become very easy to
understand. There are many kinds of charts such as bar chart, pie chart
and line graph. Think of a chart as your presentation or final report
showing all the work you have done.
To make your experiment results more
understandable, use your data tables to make graphs or
When do I make a line graph?
You make a line graph in order to show the
relation between two variables while the values for both variables are
numeric and changes are continuous. For example you may be studying the speed of wind in different heights
from 1 meter up to 150 meters.
A company that makes wind turbine,
may want to know what is the best height for a wind turbine in a certain
area. Your results table have two columns. One is the height and the
other is the wind speed. Both of these two values are numeric and the
changes are continuous.
When do I make a bar chart?
You make a bar chart in order to show the
relation between two variables when the values for one variable are
numbers and the values for the other variable are names. For example if
you are studying on the density of different material, then your results
table has two columns. One column contains the name of material (wood,
Iron, plastic, glass,..) and the other column contains the density of
such material (that is a number).