2. There are three key research designs used in
Psychology
1. Repeated Measures
2. Matched Participants
3. Independent Groups
3. Repeated Measures Design
(within participants design)
In a repeated measures design participants experience
both the experimental and control groups.
This is possible by conducting the experiment on two
occasions and then comparing the two results.
4. ADVANTAGES:
1)Using the same participants means that confounding
variables that are participant depend are eliminated.
2)Allows for fewer participants to be used than with
other designs.
DISADVANTAGES:
1) Time consuming - drop outs
2) Confounding variables such as Order Effects:
a) Participants may perform better on the task when
doing for a second time (practise effect).
b) Participants may do worse the second time because
of fatigue or boredom.
5. Counterbalancing
Used to overcome order effect.
In counterbalancing, half the participants
will first perform the task with the IV
present (experimental condition) and then
perform the task with the IV absent (control
condition). The other half of the participants
will experience the conditions in the reverse
order.
6. Matched Participants Design
Enables the researcher to identify a variable that is likely
confounding and to eliminate the effects of this variable from the
experiment.
Participants can be ranked in accordance with their scores on this
variable and then allocated to the respective groups.
7. E.G. A sports coach developed a new game plan that
would help the team reach the playoffs. He decided to
test this by giving the experimental group the
instruction but not the control group. Because
individual skills would be a confounding variable, he
decided to ‘match’ the groups. The two highest skilled
players will be randomly allocated to either the
experimental or control group, the third and fourth
most skilled will then be randomly allocated to either
and so on and so forth until all players were allocated
to a group resulting in the same mean skill percentage
in both groups.
8. Advantages: The variable on which the
participants are ‘matched’ will not influence
the results because its effects will be the
same in the experimental and control groups.
Disadvantages: It is very time consuming
(and therefore expensive) to find out the
value of this variable for every participant.
Also, if one of the pair drops out, the scores
for the other must also be eliminated.
9. Independent Groups Design
(between participants design)
Allocates participants to the
experimental or control group at random
10. Advantages: The independent groups design
can be done at once and drop-outs are
unlikely.
Disadvantages: The procedure needs a large
number of participants to ensure that the
spread of participant variables in the sample
will match the spread in the population.
11. Essential Learning Activity
Construct a concept map illustrating the types of
research/experimental designs.
* Include labelled links showing the relationship
between concepts
* Provide an advantage and disadvantage for each
method
