1. PSYA1: Cognitive Psychology Memory
“Experimental Design”
Miss Russell

2. Observations/Thoughts
Experiments
The Scientific Method..
Observations/Thoughts
Propose
a hypothesis
Gather
Evidence
Acceptp
Hypothesis
Reject
Build a theory
Publish results
Define
the Problem

3. Experiments
The Scientific Method..

4. Experiments
Once you have a theory in Psychology, this is how you go about researching it…

5. Activity

6. Research Design Research design makes a hypothesis testable.
Experiments
Research Design
Research design makes a hypothesis testable.
Participant design refers to how your participants are distributed in your experiment.
Three main types of design are used!

7. Repeated Measures Design
Experiments
Repeated Measures Design
Condition A
Condition B
There is only one group of participants. This group takes part in both conditions.

8. Independent Groups Design
Experiments
Independent Groups Design
Condition A
Condition B
Two separate groups of participants. One group takes part in condition A, the other takes part in condition B.

9. Matched Pairs Design Experiments Condition A Condition B
Two separate groups, but this time they are matched into pairs for certain qualities. One of each pair takes part in condition A, the other takes part in condition B.

10. Activity

11. Class Experiment Experiments
Research has shown that eating chocolate can improve memory. Sugar helps the brain to produce the neurotransmitter acetylcholine which helps you to learn and remember.
Aim: To investigate whether eating chocolate will improve memory.
What could our hypothesis be? Write a suitable hypothesis to test out during this experiment?

12. Hypotheses Experiments
“Students who eat chocolate before a memory test will remember more words from a list than students who did not.”
Experimental Hypothesis
Statement about a predicted outcome of a study, usually based on theory.
Null Hypothesis
This is another hypothesis that also needs to be stated. It states that the results will occur do to chance – i.e. are the results significant enough not to have occurred due to chance. It always states there will be no difference!
“There will be no difference on scores on a memory test between those who ate chocolate before, and those who did not eat chocolate.”

13. One Tailed or Two Tailed?
Experiments
Experimental Hypothesis
One Tailed or Two Tailed?
One Tailed = The direction of the results is predicted.
Students who eat chocolate before a memory test will recall more words than students who do not eat chocolate.
Two Tailed = A change or difference is predicted but a direction is not specified.
There will be a difference in the number of words correctly recalled between those students who eat chocolate and those who do not.

14. Memory Test CAR FRAME APPLE LIGHT FLOWER RING CLOCK BOWL FIRE WATCH
Experiments
Memory Test
CAR FRAME
APPLE LIGHT
FLOWER RING
CLOCK BOWL
FIRE WATCH

15. Answers CAR FRAME APPLE LIGHT FLOWER RING CLOCK BOWL FIRE WATCH
Experiments
Answers
CAR FRAME
APPLE LIGHT
FLOWER RING
CLOCK BOWL
FIRE WATCH

16. What is the IV in our experiment? What is the DV?
Experiments
IV & DV?
What is the IV in our experiment? What is the DV?
Write them down!

17. Experiments
Operationalisation
Operationalise the DV.
Write it down!

18. Which participant design should we use? Why?
Experiments
Participant Design
Which participant design should we use? Why?

19. Can you think of any problems with the participant design?
Experiments
Order Effects
Can you think of any problems with the participant design?

20. Order Effects Experiments
Order effects occur in repeated groups design, when all participants take place in all the experimental conditions.
Practice effects might occur. After they have done the first condition they may be well practised to complete the second condition.
They also may become tired after the first condition and fatigue may affect their performance on the second condition.
The solution = counterbalancing and randomisation.
Counterbalancing.
E.g. half of the participants participate in condition A before condition B and vice versa. This means that the first and second condition is not the same for every participant.
Randomisation.
Participants are assigned to condition A or B first by tossing a coin or picking out a name.

21. Additional Variables Experiments Which we can’t control!
What other factors might have affected the results?
What about things we can’t control?
Anything about the situation which may have affected our results?
Anything about the participants which may have affected our results?

22. Additional Variables Experiments Which we can’t control!
Extraneous Variables
Anything other than the IV that can influence your results. Otherwise known as a confounding variable that can’t be controlled.
Situational Variables
A type of extraneous variable found in the environment. Noise, light, time, location, temperature or weather.
Participant Variables
A type of extraneous variable found in participants. Motivation levels, moods, skills, experience, fatigue, eyesight etc.
These could all affect the VALIDITY of the findings.

23. An example… Our Experiment
Does the presence of an audience help or hinder people doing a Buzz Wire activity?
Previous research suggests that people do better without anyone watching them…

24. Our Experiment
Aim and Hypothesis
Write them down!

25. Our Experiment
IV and DV?
Which is the IV, the DV?
Write them down!

26. Operationalise your DV?
Our Experiment
Operationalisation
Operationalise your DV?
Write it down!

27. Which participant design should we use? Why?
Our Experiment
Participant Design
Which participant design should we use? Why?

28. Problems or issues with this design?
Our Experiment
Participant Design
Problems or issues with this design?

29. Worksheet