Part 1:
The Experimental Method & Design Process
Types of experiment Pg.3
Aims Pg.8
Variables & Hypotheses Pg.9
Demand characteristics& investigatoreffects pg.14
Exam questions Pg.15
Experimental designs Pg.21
Exam questions Pg. 28
Sampling Pg.34
Exam questions Pg.40
Specification Content
Experimental method. Types of experiment, laboratory and field experiments; natural and quasi
experiments.
Aims: stating aims, the difference between aims and hypotheses.
Hypotheses: directional and non-directional.
Variables: manipulation and control of variables, including independent, dependent, extraneous
confounding; operationalisation of variables.
Control: random allocation and counterbalancing, randomisation and standardisation.
Demand characteristics and investigatoreffects.
.Experimental designs: repeated measures, independent groups, matched pairs.
Sampling: the difference between population and sample; sampling techniques including: random,
systematic, stratified, opportunity and volunteer, implications of sampling techniques, including bias
and generalisation.
, 2
Introduction
nere are many different research methods which can be used in
psychological studies to investigate certain questions abouf fhe human
mind/behaviour. These methods involve collecting information in different
ways.
Ou need fo be able to describe and evaluate each of the folowing
research methods:
Experimental methods:
o Lab experiments You are also required to
o Field experiments understand the
o Natural & Quasi experiments processes researchers
undergo in designing
their investigations
Non-experimental methods
o Case Studies
o Observational methods
o Self-report methods (Questionnaires and Interviews)
o Correlations
, Types of Experiment
1. Laboratory Experiments
Key Features
1. Lab experiments are conducted in a tightly controlled, artificial
environment
2. The experimenter deliberately manipulates the independent variable
3. The experimenter measures the dependent variable (this produces
quantitative data)
4. There is an attempt to control/minimise extraneous variables (as much as is
possible)
The experimenter uses standardised procedures (including instructions)
Advant ages of Lab Experiments
Identify: Laboratory experiments have HIGH INTERNAL VALIDITY
Explain: this is because the IV is the only thing manipulated and other
(extraneous) variables are controlled. It is therefore more likely that the
IV (not any other variable) is directly responsible for any changes on
the DV.
Conclusion: This means CAUSE & EFFECT can be established.
Identify: Laboratory experiments have HIGH RELIABILITY
Explain: this is because procedures in lab experiments are standardised
Conclusion: This means that the experiment can be REPLICATED to
check the results are consistent.
, 4
Sadvantages of Lab Experimenfs
Ldentify: Laboratory experiments have LOW ECOLOGICAL VALIDITY
& MUNDANE REALISM
CXplain: this is because the setting is artificial so unlikely to represent a
real life
situation (low ECOLOGICAL VALIDITY)
Also, participants are often asked to complete artificial ich they
tasks whichthey
would not do in everyday life (low MUNDANE REALISM).
Conclusion: this means that we CANNOT GENERALISE the resultsS
beyond the laboratory to REAL LIFE
Tdentify: They suffer from DEMAND CHARACTERISTICS
Explain: this is because participants are aware they are taking part in an
experimet and may pick up on cues ("demand characteristics") that
reveal the aim. This can lead participants to change their behaviour in
order to meet the experimenter's expectations.
Conclusion: this means ppts' behaviour is UNNATURAL and doesn't
reflect their true behaviour.
2. Fielid Experiments
Key Features
1) Field experiments are conducted in a natural, real world
environment. Eg, hospital, park
2) The experimenter deliberately manipulates the independentvariable
3) The experimenter measures the dependent variable
4) There is minimal (if any) control of extraneous variables
The Experimental Method & Design Process
Types of experiment Pg.3
Aims Pg.8
Variables & Hypotheses Pg.9
Demand characteristics& investigatoreffects pg.14
Exam questions Pg.15
Experimental designs Pg.21
Exam questions Pg. 28
Sampling Pg.34
Exam questions Pg.40
Specification Content
Experimental method. Types of experiment, laboratory and field experiments; natural and quasi
experiments.
Aims: stating aims, the difference between aims and hypotheses.
Hypotheses: directional and non-directional.
Variables: manipulation and control of variables, including independent, dependent, extraneous
confounding; operationalisation of variables.
Control: random allocation and counterbalancing, randomisation and standardisation.
Demand characteristics and investigatoreffects.
.Experimental designs: repeated measures, independent groups, matched pairs.
Sampling: the difference between population and sample; sampling techniques including: random,
systematic, stratified, opportunity and volunteer, implications of sampling techniques, including bias
and generalisation.
, 2
Introduction
nere are many different research methods which can be used in
psychological studies to investigate certain questions abouf fhe human
mind/behaviour. These methods involve collecting information in different
ways.
Ou need fo be able to describe and evaluate each of the folowing
research methods:
Experimental methods:
o Lab experiments You are also required to
o Field experiments understand the
o Natural & Quasi experiments processes researchers
undergo in designing
their investigations
Non-experimental methods
o Case Studies
o Observational methods
o Self-report methods (Questionnaires and Interviews)
o Correlations
, Types of Experiment
1. Laboratory Experiments
Key Features
1. Lab experiments are conducted in a tightly controlled, artificial
environment
2. The experimenter deliberately manipulates the independent variable
3. The experimenter measures the dependent variable (this produces
quantitative data)
4. There is an attempt to control/minimise extraneous variables (as much as is
possible)
The experimenter uses standardised procedures (including instructions)
Advant ages of Lab Experiments
Identify: Laboratory experiments have HIGH INTERNAL VALIDITY
Explain: this is because the IV is the only thing manipulated and other
(extraneous) variables are controlled. It is therefore more likely that the
IV (not any other variable) is directly responsible for any changes on
the DV.
Conclusion: This means CAUSE & EFFECT can be established.
Identify: Laboratory experiments have HIGH RELIABILITY
Explain: this is because procedures in lab experiments are standardised
Conclusion: This means that the experiment can be REPLICATED to
check the results are consistent.
, 4
Sadvantages of Lab Experimenfs
Ldentify: Laboratory experiments have LOW ECOLOGICAL VALIDITY
& MUNDANE REALISM
CXplain: this is because the setting is artificial so unlikely to represent a
real life
situation (low ECOLOGICAL VALIDITY)
Also, participants are often asked to complete artificial ich they
tasks whichthey
would not do in everyday life (low MUNDANE REALISM).
Conclusion: this means that we CANNOT GENERALISE the resultsS
beyond the laboratory to REAL LIFE
Tdentify: They suffer from DEMAND CHARACTERISTICS
Explain: this is because participants are aware they are taking part in an
experimet and may pick up on cues ("demand characteristics") that
reveal the aim. This can lead participants to change their behaviour in
order to meet the experimenter's expectations.
Conclusion: this means ppts' behaviour is UNNATURAL and doesn't
reflect their true behaviour.
2. Fielid Experiments
Key Features
1) Field experiments are conducted in a natural, real world
environment. Eg, hospital, park
2) The experimenter deliberately manipulates the independentvariable
3) The experimenter measures the dependent variable
4) There is minimal (if any) control of extraneous variables
