In no way can we conclude that our work with the teachers was responsible for this increase due to the lack of control of extraneous variables
in this study.
However, no description of how theses changes were measured or any control of extraneous variables
was reported in either case study.
The extreme range of choice proportions could be interpreted as random variation around the group mean, influenced more by uncontrolled extraneous variables
than by the independent variables of delay and amount of reinforcement.
1997) study that might be addressed in future research include: (1) a relatively small sample size, (2) inadvertently using a five-point, rather than a seven-point, rating scale, and (3) the possibility that extraneous variables
confounded the results.
The Pretest-Posttest Control Group design of this study attempted to control for many extraneous variables
affecting performance on the dependent variables.
Educators must also realize there are other extraneous variables
besides the type of delivery that may retard the quality of instruction.
At the immediate post-test, extraneous variables
that may have affected participants' responses to the messages in addition to threat and efficacy perceptions were measured to control for their influences.
All of this points to genetic predisposition, rather than the myriad extraneous variables
, as being the polestar ingredient in speed improvement.