Research Methods Flashcards
What is a hypothesis?
A prediction
Directional hypothesis?
-States there will be a change and the direction that the results are expected to go
(only used if there is previous research to support it)
Non-directional hypothesis?
-States a change but does not mention the direction of the change
Operationalisation?
Clearly defining the variables in terms of how they can be measured
What is an extraneous variable?
Any variable other than the independent variable that affects the dependent variable if not controlled
(Nuisance variables)
Types of extraneous variables ?
-Demand characteristics
-Investigator effects
-Participant variables
-Situational variables
Demand charactersitic? (EV)
-Any cue from researcher / research situation that may be interpreted by the participant to reveal the purpose of the investigation ( participant changes behaviour)
Investigator effects? (EV)
Any effect of the researcher’s behaviour on the outcomes of the research ( Concious or unconcious)
Participant variables ?(EV)
Any individual differences between participants that may affect the DV
Situational variables ? (EV)
Any features ( environmental) of the experimental situation that may affect the DV
How can we control EV’s in an experiment ?
-Standardisation
-Randomisation
Standardisation
Using exactly the same procedures and instructions for all participants (eliminates situations variables)
Randomisation
The use of chance to control the effects of bias when designing materials and the order of conditions
Mundane realism /
External validity
How an experiment mirrors the real world
What is Experimental Design?
Refers to how participants are allocated to the different conditions in an experiment
What is Repeated measures design?
Only one group of participants.
This group takes part in both conditions
(both levels of the IV)
What is independent groups design?
Two separate groups of participants.One group takes part in condition A, other takes part in condition B
What is matched pairs design?
Two separate groups matched into pairs for certain qualities, such as age or intelligence. One of each pair takes part in condition A, the other takes part in condition B
Limitations of repeated measures design and how to deal with them?
The order effect.
For example fatigue, demand characteristics and boredom
How to deal:
Counterbalancing (ABBA)
Limitations of independent group design and how to deal with them?
Participant variables-Any differences between people in the two groups that could affect the results ( cant control but can restrict)
How to deal:
Random allocation
Limitations of matched pairs design and how to deal with them?
-Not possible to control all participant variables( can some)
-Time consuming
How to deal:
Pilot studies
Adavantages of the repeated measures design
-Participant variables can be eliminated( same people)
-Less participants so cheaper
Advantages of the independent group design
No order effects
Advantages of matched pairs design
Can control some participant variables
No order effects
What are order effects
An extraneous variable arising from the order in which the conditions are presented
E.G fatigue, demand characteristics, practise, boredom
Counterbalancing
Solution to order effects
-Half participants experience the conditions in one order and the other half experience them in the opposite order
(ABBA)
Random allocation
An attempt to control for participant variables in an independent group design which ensures each participant has the same chance of being in one condition as any other
Removes interviewer bias
For example, random number generator
Pilot study
A trial run of a research method, usually with a very small sample, with the aim of checking that the procedures and materials are standardised
Reliability
How consistent the findings from an experiment are ( need to be able to replicate it and standardise it)
Validity
Does the study measure what it intended to measure?
Internal Validity
Whether the effects of the experiment are down to the manipulation of the IV and not some other factor
what is a laboratory experiment
-Experiment conducted in a controlled artificial environment
-The IV is manipulated , the researcher observes the effect on the DV
Example of a lab experiment
-Milgram (1963)-
IV: Situation (authority figure)
DV: Obedience to authority
Strengths of a lab experiment
-Extraneous variables are controlled= high validity
-Standardised= easier to replicate
-More scientific and objective
-Researcher is detatched
Weaknesses of a lab experiment
-Lacks external validity (artificial environment)
-Investigator effects can occur
-Demand characteristics can occur
These lowers internal validity
What is a field experiment
-Experiment in an everyday real life setting (E.G shopping centre)
-IV is manipulated, researcher observes effect on DV
Example of a field experiment
Bickman (1974)-
Social power of uniform
IV: Uniform worn
DV: Level of obedience
Strengths of a field experiment
-Eliminates demand characteristics (unaware they are being observed)
-High external validity
Weaknesses of a field experiment
-Extraneous variables are difficult to control#
-Unethical - unaware they are being observed
-Low internal validity so less replicable
What is a natural experiment
Experiment where the researcher has not changed the IV but it has occured ‘naturally’.
-Researcher does not measure its effect on DV
-Used when it’s not ethical to manipulate IV
Example of natural experiment
-Hodges and Tizard’s attachment research (1989):
Compared the long-term development of children who had been adopted, fostered or returned home
Strengths of a natural experiment
-High external validity- involves the study of real world issues (for example effect of natural disaster on stress levels)
-More ethical
Weaknesses of a natural experiment
-Less likely to be randomly allocated to experimental conditions. Researcher may be less sure if the IV affected the DV.
-Ethical issues
-Participant variables
-Investigator effects
-Demand characteristics
What is a quasi experimental design
Conducted when the IV is based on existing difference between people (can be manipulated by the researcher e.g. gender, race, IQ)
Population
-A specific group of people who are the focus of research .From this group a small sample is drawn
Sample
A small group of people drawn from target population, represent this target population in a research investigation
Generalisability
The extent to which the results of the investigation can be applied to the target population
Random sampling?
-A sample where each member of the target population has the same chance of being chosen for the sample
-E.G assign each person a random number and select participants with a random number generator
Systematic sampling
-Researcher numbers the participants in a sampling frame (e.g 1,2,3) and then picks their participants at a set interval
-E.G every nth member of the target population
Stratified sampling
-Researchers divide participants into sub groups called strata, based on characteristics they share
-E.G Age, race, gender
Opportunity sampling
-Researcher selects the most convenient and available people for the experiment
-E.G in the streets
Volunteer sample
-Participants self-select to become part of the study after seeing it being advertised
Strengths of a random sample
-No researcher bias as they have no influence over who is selected, meaning EVs are controlled, enhancing internal validity
-Equal chances of getting selected
-Simple
-
Weaknesses of random sampling
-Time consuming
-Selected participants may chose not to take part
-Difficult to obtain a complete list of the target population
Strengths of a systematic sample
-No researcher bias
-Produces a representative sample
-simple
Weaknesses of a systematic sample
-Could refuse to participate
-Time consuming
-Difficult to obtain a complete list of the population
-May as well use random sample
Strengths of stratified sampling
-No researcher bias
-Produces a representative sample (generalised), more generalisable than other methods
Weaknesses of stratified sampling
-Complete representation of target population can not be achieved
-Could refuse to participate
-Strata can not reflect all the ways in which people are different
Strengths of opportunity sampling
-Convenient
-Quick
-Cheaper
Weaknesses of opportunity sampling
-Could refuse to participate
-Unrepresentative of the target population ( drawn from a specific area so cannot be generalised)
-Researcher bias as they ask people to participate
Strengths of volunteer sampling
-Easy
-less time consuming
Weaknesses of volunteer sampling
-Could refuse to participate
-Volunteer bias can’t be generalised ( asking for volunteers might attract a certain ‘profile’ of a person E.G someone helpful, keen)