Paper 2
Research Methods
, Research issues
Extraneous variables: additional unwanted variables Independent groups: an experimental design in which ppts
Confounding variables: change systematically with the are each in a different condition and only do one condition.
➔ Limitation - natural individuals characteristics may
IV.
Demand Characteristics: Any cue from the researchers affect DV
➔ Solution - randomly allocate ppts and distribute the
that may be interpreted by ppts as revealing the
purpose of the investigation. ppt variables evenly.
Investigator effects: Any effects of the investigators Repeated measures: the same participants take part in both
behaviour on the research outcome. conditions.
➔ Limitation - Order effect present and makes them
Randomisation: use of chance methods to control for
the effects of bias when designing materials. bored or fatigue. Demand characteristics are present
Standardisation: all participants should experience the too as they learn the aim of the study.
➔ Solution - counterbalancing checks the design first or
same environment, information and experience.
second in equal amounts.
Matched pairs: ppts are each in a different condition and only
do one condition, but are matched on key characteristics.
➔ Limitation: time consuming and exact match is rarely
possible.
➔ Solution: Restrict number of variables to match on to
or conduct a pilot study.
, Types of experiments
Lab: Conducted in a highly controlled environment and variables are Natural experiment: researcher takes advantage of a
controlled. Researcher manipulated the iv and record the effect of the naturally occurring IV, therefore they do not
dv manipulate the IV
➔ Strength
- well controlled
➔ Strength
- High internal validity
- - high ecological validity can study real
Easily replicated
➔ Limitation problems such as effects.
- low external validity ➔ Limitation
- Demand characteristics - Cannot demonstrate a casual relationship
- Artificial stimulus because IV is not directly manipulated.
- Lacks ecological validity - can't apply to real world - Random allocation is not possible.
application
- of being studied.
- Cannot randomly allocated ppts. Quasi experiment: have an IV that is based on existing
differences between people (age or gender). No one
manipulates the variable, it simply exists.
Field experiment: IV is manipulated in a natural everyday setting.
➔ Strengths
➔ Strengths:
- environment is more natural
- allows comparisons between types of people
- Higher ecological validity
- Ppts unaware of being studied
- Controlled conditions
➔ Limitation: ➔ Limitation
- loss of control over extraneous variables - demand characteristics ppts may be aware of
- Ethical issues can't give consent. being studied.
- No controlled setting - Cannot randomly allocated ppts.
Research Methods
, Research issues
Extraneous variables: additional unwanted variables Independent groups: an experimental design in which ppts
Confounding variables: change systematically with the are each in a different condition and only do one condition.
➔ Limitation - natural individuals characteristics may
IV.
Demand Characteristics: Any cue from the researchers affect DV
➔ Solution - randomly allocate ppts and distribute the
that may be interpreted by ppts as revealing the
purpose of the investigation. ppt variables evenly.
Investigator effects: Any effects of the investigators Repeated measures: the same participants take part in both
behaviour on the research outcome. conditions.
➔ Limitation - Order effect present and makes them
Randomisation: use of chance methods to control for
the effects of bias when designing materials. bored or fatigue. Demand characteristics are present
Standardisation: all participants should experience the too as they learn the aim of the study.
➔ Solution - counterbalancing checks the design first or
same environment, information and experience.
second in equal amounts.
Matched pairs: ppts are each in a different condition and only
do one condition, but are matched on key characteristics.
➔ Limitation: time consuming and exact match is rarely
possible.
➔ Solution: Restrict number of variables to match on to
or conduct a pilot study.
, Types of experiments
Lab: Conducted in a highly controlled environment and variables are Natural experiment: researcher takes advantage of a
controlled. Researcher manipulated the iv and record the effect of the naturally occurring IV, therefore they do not
dv manipulate the IV
➔ Strength
- well controlled
➔ Strength
- High internal validity
- - high ecological validity can study real
Easily replicated
➔ Limitation problems such as effects.
- low external validity ➔ Limitation
- Demand characteristics - Cannot demonstrate a casual relationship
- Artificial stimulus because IV is not directly manipulated.
- Lacks ecological validity - can't apply to real world - Random allocation is not possible.
application
- of being studied.
- Cannot randomly allocated ppts. Quasi experiment: have an IV that is based on existing
differences between people (age or gender). No one
manipulates the variable, it simply exists.
Field experiment: IV is manipulated in a natural everyday setting.
➔ Strengths
➔ Strengths:
- environment is more natural
- allows comparisons between types of people
- Higher ecological validity
- Ppts unaware of being studied
- Controlled conditions
➔ Limitation: ➔ Limitation
- loss of control over extraneous variables - demand characteristics ppts may be aware of
- Ethical issues can't give consent. being studied.
- No controlled setting - Cannot randomly allocated ppts.
