scatter
plot, trend, line of best fit
(trend line), independent
variable, dependent
variable, discreet variable,
continuous variable, positive correlation,
negative
correlation, weak
correlation, strong
correlation

Learning Outcomes:
The student will:
Line of Best Fit
The correlation coefficent (r)
ranges between 1 and 1. It is part of the following applet, but will not critical
to this lesson. It is useful, however to help us understand the strength of data
correlations.
Correlation 
Strong 
Weak 
 Positive
 up and right

0.7 to 1.0 
0.3 to 0.7 
 Negative
 down and left

1.0 to 0.7 
0.7 to 0.3 
Little or No Correlation: 0.3 to
0.3 
Directions: Use the following to examine 3
scatterplot samples and to create your own scatterplots.
 Click the "Load Data File" button to see the first scatterplot sample.
The other samples are available from the pulldown menu. To display the sample, click
the "Load Data File" button after selecting a sample.
 Click on various spreadsheet cells and change the values.
 Click "Enter"in either cell of the last row if you wish to add additional
data.
 Click on "Update Display" to plot the points. Notice the effect the
change has on the line of best fit.
 Create your own scatterplots by entering the data points into the spreadsheet to the
left of the graph.
 The correlation coefficent ranges between 1 and 1. It is part of the applet,
but will not critical to this lesson. It is useful, however to help us understand
the strength of data correlations.
source: http://math.hws.edu/javamath/config_applets/index.html 
Positive Trend
positive trend (correlation)  both sets of data increase
together
Perfect Positive Trend (Correlation)
source: Correlation
Olympic Gold Medal Winning High Jump (1900  1984)
source: quizregsol.html
1993 Chicago Bulls Basketball

Negative Trend
negative trend (correlation)  one set of data decreases
as the other set of data increases
Strong Negative Trend (Correlation)
Weak Negative Trend (Correlation)
source: Correlation

No Trend (Correlation)
source: Correlation

Correlation Strength
 The correlation coefficent ranges between 1 and 1. It is part of the applet,
but will not critical to this lesson. It is useful, however to help us understand the
strength of data correlations.
Correlation 
Strong 
Weak 
Positive 
0.7 to 1.0 
0.3 to 0.7 
Negative 
1.0 to 0.7 
0.7 to 0.3 
Little or No Correlation: 0.3 to
0.3
Linked to applet at: http://www.seeingstatistics.com/seeing1999/gallery/CorrelationPicture.html

Study the following results:
In this experiment:
 what are the dependent and independent variables?
 are the variables continuous or discrete?
 is the relationship between the dependent and independent variables linear or
nonlinear?
 what trend is illustrated?

Click Reload Page
between answers selections. 

source: bios150WMU
In this experiment:
 what are the dependent and independent variables?
 are the variables continuous or discrete?
 is the relationship between the dependent and independent variables linear or
nonlinear?
 what trend is illustrated?

Click Reload Page
between answers selections. 

source: Welcome
to the Line Graph page!
In this experiment:
 what are the dependent and independent variables?
 are the variables continuous or discrete?
 is the relationship between the dependent and independent variables linear or
nonlinear?
 what trend is illustrated?

Click Reload Page
between answers selections. 

