The document outlines research methods in psychology, focusing on the distinction between independent variables (IV) and dependent variables (DV), including examples of experiments. It discusses various experimental designs: laboratory, field, and natural (quasi) experiments, highlighting their strengths and weaknesses in terms of validity, reliability, and ethical considerations. It emphasizes the goals of psychological research: to describe, explain, predict, and control psychological phenomena.

1. Research Methods in
Psychology
How do we study Psychology?

2. Goals of Psychological Research
Define and Describe: What happened?
Explain: Why did that happen?
Predict: Under what conditions is that likely to
happen again?
Control: How can I we apply our principle to
make this happen again? To make sure it never
happens again?

3. IV’s and DV’s
Independent variable (IV) :
Variable the experimenter manipulates (i.e.
changes) – assumed to have a direct effect on
the dependent variable.
Dependent variable (DV) :
Variable the experimenter measures, after
making changes to the IV that are assumed to
affect the DV.

4. What is the independent
variable?
A researcher wants to determine if the
color of an office has any effect on worker
productivity. In an experiment, one group
performs a task in a yellow room while
another performs the same task in a blue
room.
In this example, the colour of the office is
the independent variable.

5. What is the independent
variable?
Researchers want to learn whether
listening to fast-paced music helps runners
perform better during a marathon. In an
experiment, one group of runners listens to
fast-paced music while another group
listens to slow-paced music.
In this example, the type of music the
runners listen to is the independent
variable.

6. What is the independent
variable?
A business wants to determine if giving
employees more control over how to do
their work leads to increased job
satisfaction. In an experiment, one group of
workers is given a great deal of input in
how they perform their work, while the
other group is not.
The amount of input the workers have over
their work is the independent variable in this
example.

7. What is the independent
variable?
Educators are interested in whether
participating in after-school math tutoring
can increase scores on standardized math
exams. In an experiment, one group of
students attends an after-school tutoring
session twice a week while another group
of students does not receive this additional
assistance.
In this case, participation in an after-school
math tutoring is the independent variable.

8. What is the independent
variable?
Researchers want to determine if a new
type of treatment will lead to a reduction in
anxiety for patients suffering from social
phobia. In an experiment, some volunteers
receive the new treatment, another group
receives a different treatment, and a third
group receives no treatment.
The independent variable in this example is
the type of therapy.

9. What is the dependent variable?
Researchers want to discover if listening to
classical music helps students earn better
grades on a mathematics exam.
In this example, the scores on the
mathematics exams are the dependent
variable.

10. What is the dependent variable?
Researchers are interested in seeing how
long it takes people to respond to different
sounds.
In this example, the length of time it takes
participants to respond to a sound is the
dependent variable.

11. What is the dependent variable?
Researchers want to know whether first-
born children learn to speak at a younger
age than second-born children.
In this example, the dependent variable is
the age at which the child learns to speak.

12. What is the dependent variable?
Researchers are interested in looking at
how alcohol use influences reaction times
while driving.
The amount of alcohol a participant injects
is the independent variable, while their
performance on a driving test is the
dependent variable.

13. What is the dependent or
Independant variable?
Look at the question sheet:
Can Science Answer This Question?
Decide what would be the
independent and dependant variables

14. Experiments
Laboratory Experiments:
These take place in either a lab or in a controlled
environment setting, which is unnatural for the
participants. They attempt to control all variables
except the IV.
By changing one variable (the IV) while measuring
another (the DV) while we control all others, as far
as possible, then the experimental method allows
us to draw conclusions with far more certainty than
any non-experimental method.
If the IV is the only thing that is changed then
a cause and effect relationship can be found
between the IV ad the DV.

15. Experiments
Field Experiments :
Sometimes it is possible to carry out experiments
in a more natural setting, i.e. in ‘the field ’. As
with the laboratory experiment, the independent
variable is still deliberately manipulated by the
researcher.
However it is not possible to have such tight
control over variables in the field, but it does
have the advantage of being far less artificial
than the laboratory.

16. Experiments
Natural (quasi) Experiments :
Natural experiments may take place in the lab or
field. Like other experiments they have an IV but in
this type of experiment the experimenter does not
directly manipulate the IV.
Some IVs are not open to manipulation as some
conditions are pre-decided by fixed characteristics.
E.g. comparing men and women’s driving skills,
they cannot be randomly allocated to be male or
female. The IV is naturally occurring. Other
examples of pre-existing variables might be age,
IQ, position in the family and social background.

17. Experiments
Your turn:
Think of at least one strength and one weakness of
a lab experiment, a field experiment and a natural
(quasi) experiment.
You have 10 mins max to complete this.
Yes, write your answers down.
Yes, you may discuss with a partner.

18. Experiments
Laboratory Experiments: Strengths
1.Laboratory experiments have high levels of
standardisation and so can be replicated to test for
reliability.
2.As Laboratory experiments have high levels of
control, researchers can be more confident it is the
IV directly affecting the DV.

19. Experiments
Laboratory Experiments: Weaknesses
1.As laboratory experiments take place in an
artificial setting, it is said that they can lack
ecological validity. Many laboratory experiments
make participants take part in tasks that are
nothing like real life ones, so the tasks lack
mundane realism.
2.Participants usually know they are taking part in
an experiment and they may respond to demand
characteristics as something about the set-up
indicates the aim of the experiment.

20. Experiments
Field Experiments: Strengths
1.As field experiments take place in a realistic
setting, it is said that they have good ecological
validity.
2.As participants will not know they are taking part
in a study, there will be little or no demand
characteristics so behaviour is more likely to be
natural and valid.

21. Experiments
Field Experiments: Weaknesses
1.Situational variables can be difficult to control, so
sometimes it is difficult to know whether it is the IV
affecting the DV. It could be an uncontrolled
variable causing the DV to change.
2.As participants will not know they are taking part
in a study, there are issues with breaking ethical
guidelines. These include the issues of informed
consent and deception.

22. Experiments
Natural (quasi) Experiments: Strengths
1.As the experiment is located in a natural setting
exploiting a naturally occurring IV, the study should
be high in ecological validity.
2.As participants are usually unaware that a study
is taking place, their behaviour is more likely to be
natural and a valid representation of each person’s
behavioural repertoire

23. Experiments
Laboratory experiments:
Validity These experiments have high internal validity because controls
mean the researcher can be confident it is the IV directly affecting
the DV.
They have low external validity as it may be difficult to apply the
findings to a real life situation.
Reliability These have high levels of reliability because controls and
standardised procedures allow for full replication.
Ethics It is usually easy to gain informed consent. Deception can be dealt
with through a full debrief.
Participants know they are in a study so can withdraw at any time.
Internal validity refers to whether it is the IV directly affecting the DV
External validity refers to the extent to which the findings of the study can be
applied to real life settings and to other people outside the sample.

24. Experiments
Field experiments:
Validity These experiments have lower internal validity as the researcher can
control some variables but not all of them.
There is stronger external validity than in laboratory experiments due
to the “field” setting of the study.
Reliability These have medium levels of reliability as some elements of the
study are controlled with some standardised procedures but full
replication may be difficult.
Ethics Researches can gain informed consent from participants, but it is not
always possible.
Participants may not know they are part of a study which can make
debriefing difficult and sometimes impossible.
(Also if participants do not know they are in a study their right to
withdraw is invalidated)

25. Experiments
Natural (quasi) experiments:
Validity These experiments have low internal validity as there is no control
over any extraneous variables.
Natural experiments have high external validity as they take place in
participants’ natural environment.
Reliability These have low levels of reliability as there is hardly any controls or
standardisation and this makes replication very difficult.
Ethics There are several issues.
Informed consent can be very difficult to obtain, depending on the
study.
People may not know they are part of a study which can make
debriefing difficult and sometimes impossible.
(Also if participants do not know they are in a study their right to
withdraw is invalidated)

26. The Marshmallow Test

27. Dictionary
Your task:
Cut out the key words and match them to the
definitions.