2DIFFERENT TYPES OF GRAPHS Line graphsSector graphsPicture graphsBar graphsStep graphsColumn graphs
3The main types of graphs used in science are: Type of graphForm of informationWhy they are usedColumn/bar graphGroups of things that have been measured or counted.Used to compare things.Line graphTwo quantities that have been measured or counted. One is usually time.Used to show trends or changes over time.Pie graphPercentages or proportions of different things that make up a whole.Used to compare the relative sizes of things.
6Interpreting graphs:In order to interpret a graph there are a number of important parts that you must be able to identify and read. Most graphs will have a:Title. This gives you a short explanation of what the graph is about.Horizontal axis. This is a line running across the graph. It has a label beneath it. It may have a scale.Vertical axis. This is a line running up the side of a graph. It has a label next to it. It may have a scale.The scales. The scales on horizontal or vertical axes are similar to the scales found on many measuring instruments. A scale is a series of numbers that are increasing or decreasing by the same amount. Part of the skill of interpreting a graph is reading the scales on the axes. Each scale will be labelled with the unit of measurement that has been used.In addition some graphs will have a:Source. This tells you where the information has come from.Key. This explains any symbols used in the graph.
7Line graph Summary A line graph has two lines or axes. Is often used to represent a set of data values in which a quantity varies with timeOne is the horizontal axis which goes from side to side.Line graphThe other is the vertical axis which goes up and down.A line graph is used to show the relationship between two variables.Shows how one thing is affected by another.
8Plot the points accurately with a small dot or x. Things you should follow when drawing a line graphuse graph paperPlot the points accurately with a small dot or x.use a pencildraw in the two axeswith a ruler
9Line graphLine graphs are useful for showing how things change over time.Mass depends on the temperatureVertical axisHorizontal axisJump= 50Spaces= 2Each line =50/2= 25Temperature does not depend on massJump= 20Spaces= 2Each line =20/2= 10
10ExampleThis table shows the result of Dina’s pulse rate after running in the Junior Quad, measured after each minute. Draw a graph for Dina’s result.TimePulse rate(beats per minute)7017829731084102587
11Step 1: draw the axesStep 2: identify the dependent and the independent variables. (Pulse rate depends on the time so time is the independent and goes on the horizontal axis)Step 3: draw the axes and label themStep 4: setting up the scales. The scale for each axis is different. On the horizontal axis its going up by 1. On the vertical axis its going up by 20)Step 5: draw the lineGraph of pulse rate after exerciseStep 6: add a titleTimePulse rate(beats per minute)7017829731084102587Pulse rate (beats per minutes)Time (Minutes)
12Title Graph of pulse rate after exercise Step 1: Draw the axes Step 2: Pulse rate depends on the time so it goes on the horizontal axis.. Time goes on the vertical axis.Step 3: Label themStep 4: Setting up the scales. Count how may squares represent one. (same interval).Pulse rate (beats per minutes)60The scale for each axis is different. On the horizontal axis its going up by 1. On the vertical axis its going up by 20)4020Step 5: Putting up the values and draw the line123ScaleTime (Minutes)Step 6: Add a title