Reseach Methods - Unit 4 Flashcards
Theory
A suggested explanation for behavior
Aim
A general statement that explains the purpose of a study
Independent variable
The variable that the experimenter is deliberately changing - there are usually two levels of the IV
Dependent variable
What is measured by the researcher, the only thing that should affect the DV is the IV
Operationalisation
Making sure that variables are measurable, clear and precise
Testable hypothesis
A clear and precise testable statement
Alternative hypothesis
A statement of relationship or difference between variables
Null hypothesis
A statement of no relationship or difference between variables
Cause and effect
The only thing that should cause a change in the DV is the IV, if the DV does then change, the experimenter has established cause and effect
Extraneous variables
Unwanted variables that could affect the DV as if they are not controlled
Standardised instructions
Giving the participants exactly the same information about the study to ensure what Is said to them doesn’t act as an EV
Standardised procedures
Researcher used the same method and instructions for all participants in a research study
Lab experiment
An experiment conducted in a controlled environment
Give 4 evaluations of lab experiments
STRENGTH - Ev’s can be controlled which means that cause and affect can be established
STRENGTH - use of standardised. Procedure ensures replication is possible so it is possible to confirm the validity of results
WEAKNESS - Environment is unnatural to participants so they might act differently, results cant be generalised
WEAKNESS - participants may change their behaviour because they know that they are being tested
Field experiment
An experiment conducted in a natural setting experimenter manipulated the IV
Give 4 evaluations of field experiments
STRENGTH - often more realistic than lab experiments due to their natural environment which increases the validity of results
STRENGTH - there is some control over EV’s as standardised procedures can be used so cause and effect conclusions are more valid
WEAKNESS - researcher may lose control of some EVs becuase a real life setting makes it more difficult to control them
WEAKNESS - ethical issues to do with participants not knowing that they are bing studied, so cant give informed consent.
Natural experiment
An experiment conducted in a natural or lab setting where the experimenter has no control on the IV
Give 4 strengths and weaknesses of a natural experiment
STRENGTH - natural experiments usually have high validity. This is because the variables are naturally occurring and relate to everyday life.
STRENGTH - the DV is often tested in a lab. Therefore EVs can be well-controlled because standardised procedures can be followed.
WEAKNESS- there may be few opportunities for this kind of research. This is because it may focus on natural events that occur infrequently. This reduces the usefulness of the method.
WEAKNESS - there may be a greater amount of EVs that could affect the results. For example, unique characteristics of the participants cannot be controlled because they cannot be randomly assigned to groups.
Independent groups
Separate groups of people for each level of the IV.
There is usually a control group and an experimental group.
Give 2 evaluation points of independent groups design
STRENGTH - order effects are not a problem. The participants only do the task once. This means they won’t benefit from practice.
WEAKNESS - different participants in each group. This means that participant variables may affect the results and act as an EV. This reduces the validity of the results.
Repeated measures
All participants take part in all the conditions.
Give three evaluation points of Repeated measures design
STRENGTH - there are no participant variables. Each participant is compared against themselves rather than other people. This enhances the validity of the results.
STRENGTH- fewer participants are needed. In an independent groups design you need twice as many participants to get the same number of data items. This makes repeated measures less expensive.
WEAKNESS - A weakness is that order effects occur when participants are tested twice. The order in which they do the tasks may make a difference, e.g. a practice effect. This affects the validity of the results.
Matched pairs
Participants are tested in terms of variables relevant to the study, participants are then matched and one member of each pair goes in each group
Give three evaluation points for matched pairs design
STRENGTH - there are no order effects, enhancing validity
STRENGTH - There are fewer participant variables because those taking par are matched on a variable important to the experiment; this enhances the validity of the results
WEAKNESS - matching participants takes time and effort and still doesn’t control all participants so may not be worthwhile
Target population
The group of people the researcher is studying
Sample
A sample of participants chosen from the target population
Generalisation
The sample should be representative so we can generalise to the target population
Bias
It is difficult to select a group of participants that perfectly reflects the target population
Give 4 types of sampling
Random
Opportunity
Systematic
Stratified
Random sampling
Putting names of all members of the target population into a hat/computer programme so that every member of the target population has an equal chance of being selected.
Give two evaluation points of random sampling
STRENGTH - there is no bias. Every person in the target population has an equal chance of being selected. This makes the sample more representative.
WEAKNESS - takes more time and effort than other methods. This is because you need to obtain a list of all the members of your target population and then randomly select them. The effort may not be worth it.
Opportunity sampling
Selecting the most readily available group of people.
Give the two evaluations of opportunity sampling
STRENGTH - it is easy, quick and cheap to carry out because you simply choose people who are nearby. This makes the method less expensive.
WEAKNESS - the sample is likely to be unrepresentative of the population. This is because the sample is drawn from one place. This reduces the generalisability of the results.
Systematic sampling
Selecting every nth person from a list of all the people in the target population.