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: www.ricksmath.com 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.

DirectIndirect /

Inverse

Cyclic

Dynamic Equilibrium