A2 Psychology


Psychologists, like all scientists, use the
Scientific Method to produce valid
explanations of the world around them.
This method has both advantages and
disadvantages.





The Scientific process starts with observations of phenomena
in the world.
In the Inductive Model this then leads to the developments of
hypotheses.
Hypotheses are tested which may lead to new questions and
new hypotheses.
Eventually such data may be used to construct a theory.
The Deductive Model theory construction at the beginning of
the process, after making observations.
Example: the
spontaneous
generation
theory
Life emerges
from nonliving matter
Make
Observations
Reject the theory
No mice!!!!
Place dirty
socks in a
glass jar for
a few days
Mice emerge
from dirty
socks
Hypothesis
Experiment
Deductive process
Inductive
process
Theory







Referring back to the definition of ‘Scientific’, any research
can be considered scientific as long as it collects data in an
objective, controlled manner.
The following research methods have been put in order of
how scientific they are considered to be.
Lab Experiments
Field Experiments
Natural Experiments
Interviews/Questionnaires
Observations





The left picture is a burger from McDonalds.
Or it is at least what you are led to expect you will get.
What about reality?
You may think you know something but unless you test this
empirically you cannot know if it is true.
The right picture is the empirical evidence of what the burgers are
really like.

So what is Empirical Data?
Empirical data is information gained through direct
observation or experiment rather than reasoned argument or
unfounded beliefs.

The Scientific aims to collect the facts.



Why is this an advantage?
People can make claims about the truth of a theory or the
benefits of a treatment but the only way we know such things
are true is through empirical evidence.




An important aspect of empirical data is that they are
objective.
What does this mean?
That the data is not affected by the expectations of the
researcher.
Systematic collection of measurable data is at the heart of the
method.

How would an experimenter allow for greater objectivity?

Usually via standardised procedures and instructions.

Why is this an advantage?

Without objectivity we have no way of being certain that data
collected is valid.

The aim of the Scientific Method is to test hypotheses by
falsifying them.
i.e. rejecting a null hypothesis.

Why is this an advantage?




Because it is not possible to prove a hypothesis correct but
you can prove it is wrong.
i.e. falsify it.
“no amount of observations of white swans can allow the
inference that all swans are white, but the observation of a
single black swan is sufficient to refute that conclusion”

The ideal form of the scientific method is a lab experiment
because is enables the researcher causal relationships.

What is a causal relationship?

Showing cause and effect.


The experimental method is the only way to do this –
where we vary one factor (independent variable) and observe
it’s effects on the a dependent variable.





In order for this to be a ‘fair test’ all other conditions must be
controlled, and the best place for this is in a lab setting.
What are extraneous variables?
Any other variables apart from the IV that could in truth affect
the DV.
Why is this an advantage?
If we can’t demonstrate causal relationships then we can’t be
sure, for example, a person’s anxiety was reduced by the
drug used.





Scientists record their methods and standardise them
carefully so that the same procedures can be followed in the
future.
i.e. replicated.
Why is this an advantage?
Repeating a study is the most important way to demonstrate
the reliability and validity of an observation or experiment.
If the outcome is the same this affirms the truth of the
original results.







In pairs
You need to come up with as many advantages for each study
you can think of and relate back to the advantages of the
Scientific Approach.
Milgram’s (1963) study on Obedience.
Asch’s (1951) study on Conformity.
Selye’s (1935) study on Stress
Loftus and Palmer’s (1974) study on Eyewitness Testimony.
Gibson and Walk’s (1960) study of Depth Perception.







APFCC for following studies:Milgram’s (1963) study on Obedience.
Asch’s (1951) study on Conformity.
Selye’s (1935) study on Stress
Loftus and Palmer’s (1974) study on
Eyewitness Testimony.
Gibson and Walk’s (1960) study of Depth
Perception.
Gardner and Gardner, Language acquisition
in a chimp.
1.
2.
One advantage of the scientific method is
that it is objective………..
a) Describe how Gardner and Gardner’s
study is objective
b) Why does the fact that it is objective
make the findings more convincing?
Another advantage of the scientific method
is that it is empirical………
2. a)Describe how Asch’s study is empirical
b) Why does that fact that it is empirical
make the findings more convincing?
1.
1. Another advantage of the scientific method
is that the theories are falsifiable
2. a)Describe how Selye’s research is falsifiable
b)Why does this falsifiability make the
findings more convincing?



1. Another advantage of the scientific method
is that research is replicable
2. a)Describe why Milgram’s research is
replicable
b) Why does the fact that the research is
replicable make the findings more
convincing?



1.Another advantage of the scientific method
is that it is controlled i.e lab experiment
2. a) Describe why Loftus and Palmer’s
research was controlled
b) Why does the fact that the research is
controlled make the evidence more
convincing?






Cause and Effect
The Scientific Method lets us state that it is the IV causing
changes in the DV.
Quantitative Data
This can be collected and then be analysed using descriptive
and inferential statistics tests, which can then be used to
prove or disprove a hypothesis.
Participants
With Scientific methods, especially lab experiments, you can
choose the participants that best represent your target
population.






Problems include:Situational variables
Participant variables
Demand characteristics
Why is this a disadvantage?
The observed effects may be due to variables
other than the IV.



Ecological validity is a problem when artificial
settings are used.
Why is this a disadvantage?
Findings cannot be generalised to the real
world phenomena



Operationalised variables in experiments and
behavioural categories in observations reduce
the complexity of behaviour.
Why is this a disadvantage?
Explanations of behaviour become oversimplified.



The nomothetic approaches looks to
generalise findings to all people.
Why is this a disadvantage?
Uniqueness and difference between genders,
cultures and ages are ignored.




Experimental and observation methods often
involve psychological harm and deception
which is seen as necessary to maintain
scientific rigour.
Why is this a disadvantage?
Participants may be harmed
Psychology could be brought into disrepute.




Investigator affects
The scientific method does not acknowledge
that subjectivity of the researcher can affect
the results.
Cultural/gender biases
A necessity to be able to generalise scientific
findings means that they could be
ethnocentric/androcentric.



Read through the example essays and
highlight and identify the key
advantages/disadvantages.
Highlight in a different colour where the
person has used examples of research to
support their arguments
Highlight in a different colour
linking/signpost words used to give the essay
good structure.

Identify three things that you have
learnt/found useful from reading these
essays







You are going to complete an essay each by
building on the points already made by others.
This is how:Everyone write an introduction to the question:-
Discuss the advantages of using the scientific
method in psychology (15)
Write one point including one advantage, reason
why it’s good and an example -pass your essay
on.
Read the comments already written and write the
next point then pass it on.
Do this until we have 5 points.
Return the essays to the original writer and mark
them using the handout with the bubbles.