STA 630 - GDB FALL 2011

Topic/Area for Discussion

“Types of variables”

Discussion Question

Both, the Moderating and Extraneous variables have an influence on the relationship between the dependent and independent variable. Discuss the basis on which we can differentiate moderating and extraneous variables?

STA630_GDB IDEA SOLUTION FALL 2011
Solution here:



Moderating variable

1- strong contingent effect
on the independent
variable-dependent
variable relationship.


2-presence of a third
variable modifies the
original relationship

3-a moderator is a
qualitative or quantitative
in nature

4-Effect the direction and
strength of relationship
between predictor and
criterian variable


5-Moderator effects zero
order correlation between
two variables

6-they don’t add error to
experiment.


Extraneous Variables


1-conceivably affect on the
independent variable –
dependent variable
relationship

2-To identify the true
relationship effect of the
extraneous variables may
have to be controlled

3-Confounding factors is
another name
used for extraneous
variables

4-Extraneous Variables
are undesirable variables

5-They influence the
outcome of an experiment
6- they add error to an
Experiment