Graphing In Science BRAINSTORM Why is it important for scientists to organize their data? List as many ways as you can that scientists organize information visually. Describe what a table is made up of. What kind of information is usually shown in a table?

A graph is a way for scientists to show data in a way that is easy for others to understand and to compare multiple variables. Information from data tables is used to make a graph.

Types of Graphs There are many different types of graphs. Most common are: Line graph Bar graph Circle graph Scatter graph

Pie Graph Bar Graph Line Graph Scatter Graph with Line of Best fit

Graphs have two axis. -The horizontal axis is the X axis it usually is where the independent variable is graphed - The vertical axis is the Y axis it usually is where the dependent variable is graphed

1.A Title The title should be informative and should tell the reader about the information contained in the graph…

 Almost every graph you will complete in SCIENCE class will be a line graph or x-y scatter graph. They look like this:

 The independent variable (the one that you control) is placed on the x-axis and the dependant variable (the one that responds) should be placed on the y-axis.  Decide, based on your experiment, which variable is dependant and which is independent, and begin to construct your axis.

 A graph that is too small is difficult to read and a graph that is too big will not fit on the page.  Your graph should fill at least ¾ of the page, this requires careful planning, to think carefully about your graph BEFORE labeling your axis.

 You should choose an appropriate scale for your axis, the intervals should be equally spaced and they should also be selected based on the range of your data.  For example, given the data below, 1.5 m, 5.3 m, 2.6 m, 3.7m and 6.8m The best choice for your scale would be in intervals between.1 m and.5 m, based on the space available, or the number of squares on the graph paper.  ALSO… the scale does not need to be the same on both axis.

 Every graph should have a label for each axis clearly marked.  This allows the reader to gather all the information needed to interpret the graph.

 You should always include a unit for each axis.  The unit should be written next to the label and placed in (parenthesis).  This ensures that the graph will be correctly interpreted.

 You will not always need to include a line of best fit  If there is a trend in your data it is usually appropriate to include a line of best fit.  In SCIENCE, a line of best fit is not always a straight line. Sometimes it is curved.  Also it does not always go through (0,0) (the origin.)  Since we will be plotting experimental data the line of best fit won’t connect all the points, but it should show a general pattern in the points.

 Every graph should have your name on it, along with the date and your class period. So we can give you the credit you deserve!

 Every graph that you will do this year needs to be done on GRAPH PAPER or the computer (if your teacher lets you)  You should always use PENCIL for graphing.  NEVER use pen for a graph.  If you do not use pencil or graph paper, your graph will not be accepted.  If you need graph paper and you have none at home, visit the following web site:   Or search on Google images for “graph paper”

Graphing Relationships Direct relationship - as x gets bigger, y gets bigger. For example, the relation ship between age and size (until maturity) is a direct relationship. Indirect / Inverse - as x gets bigger, y gets smaller. For example, the relationship between time spent at the mall and the amount of money in your pocket is an inverse relationship. Dynamic Equilibrium – the two variables are equal to and opposite each other. Cyclic - a repeating pattern.

Direct Indirect / Inverse Cyclic Dynamic Equilibrium