Research methods notes Flashcards
What is the experimental method?
Experimental method - involves the manipulation of an independent variable to measure the effect on the dependent variable. Experiments may be laboratory, field, natural or quasi
What is an aim?
Aim - the purpose of a study - statement of what the researcher intends to investigate - always written in present tense
What is a hypothesis?
Hypothesis - a clear, precise, testable statement that states the relationship between the variables to be investigated. Stated at the outset of any study
What is a variable?
variables - any ‘thing’ that can vary or change within an investigation. Variables are generally used in experiments to determine if changes in one thing result in changes to another
What is an Independent variable?
IV - some aspect of the experimental situation that is manipulated (changed) by the researched, or changes naturally, so the effect on the dependent variable can be measured
What is a dependent variable?
DV - the variable that is measured by the researcher. Any effect on the DV should be caused by the change to IV.
What is operationalism?
Operationalism - clearly defining variables in terms of how they can be measured
what is debriefing?
Debriefing - a post- research interview designed to inform participants of the true nature of the study and restore them to the state they were in at the start of the study. It may also be used to gain useful feedback about the procedures of the study. Debriefing is not an ethical issue; it is a means of dealing with ethical issues
what are ethical issues?
Ethical issues - concern questions of right and wrong. They arise in research where there are conflicting sets of values between researchers and participants concerning the goals, procedures or outcomes of a research study.
what is informed consent?
Informed consent - participants must be given comprehensive information concerning the nature and purpose of the research and their role in it, in order that they can make an informed decision about whether to participate
what do you need to include when writing a hypothesis?
- writing a hypothesis
- Identify both conditions of the independent variable and the dependent variable
- explain how we would operationalise (turning abstract conceptual ideas into measurable observations - is useful in making experiment replicable) these variables
- explain how you think the IV will impact the DV
- e.g. want to find out whether boys or girls watch more tv
- IV - boy or girl - female and male students aged 12-13 years
- DV - how much they watch - in hours
- I think that women will watch more tv than boys do
what is a directional hypothesis?
directional hypothesis - states the kind (or direction) of difference or relationship expected between two conditions or groups of participants e.g. increased study time will lead to better exam results from students
what is a non directional hypothesis?
- non directional hypothesis - states that there will be difference between the conditions, but doesn’t predict the direction e.g. there is a difference between work produced in quite and noisy conditions
- usually used when there is no previous research done
what is a null hypothesis?
null hypothesis - the opposite of an alternative/ experimental hypothesis. Its when you predict that there is no difference or association between the variables that you are studying. In psych research is conducted to try to prove this hypothesis wrong
what is an alternative hypothesis?
alternative hypothesis - an opposing theory to another hypothesis - umbrella term for directional and non directional hypothesis
what is an experimental hypothesis?
experimental hypothesis - predicts the changes that will take place in the DV when the IV is changes
What is a confederate?
Confederate - an individual in a study who is not a real participant and has been instructed on how to behave as a participant
What is a piolet study?
- Pilot study - a small-scale trial run of a study to test any aspects of the design, with a view of making improvements
- note any results of a pilot study are irrelevant
what is an extraneous variable?
Types of experiment and extraneous variables:
- extraneous variable - a variable that does not vary systematically with the independent variable but may have an effect on the dependent variable - any variable other than the IV taht may have an affect on DV if not controlled
- They are variables that might affect the dependent variable and so need to be controlled
what is a confounding variable?
- confounding variable - any variable other than IV that may have affected the DV so we cannot be sure of the true source of changes to the DV. They vary systematically with the IV
- they are variables that were not controlled in the study and so have affected the results
what are demand characteristics?
demand characteristics - any cue from the researcher or from the research situation taht may be interpreted by participants as revealing the purpose of the investigation. This may lead to a participants changing their behaviour within the research situation
what is randomisation?
randomisation - the use of chance in order to control for the effects of bias when designing materials and deciding the order of conditions
what is standardisation?
standardisation - using exactly the same formalised procedures and instructions for all participants in a research study
what are investigator effects?
- Investigator effects - occur when a researcher unintentionally, or unconsciously influences the outcome of any research they are conducting.
- This can be done in several ways:
what is external validity?
external validity - the degree to which a research finding can be generalised; to other settings (ecological validity); to other groups of people (population validity); over time (historical validity)
what is internal validity?
Internal validity - the degree to which an observed effect was due to the experimental manipulation rather than other factors such as confounding/ extraneous variables
what is mundane realism?
mundane realism - refers to how a study mirrors the real world. The research environment is realistic to the degree to which experiences encountered in the research environment will occur in the real world.
what is experimental design?
Experimental design - the different ways in which the testing of participants can be organised in relation to the experimental conditions
what is random allocation?
Random allocation - an attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other
what is counterbalancing?
- Counterbalancing - an attempt to control for the effects of order in a repeated measures design: half the participants experience the conditions in one order, and the other half in the opposite order
- there are two ways to counterbalance order effects:
1. AB or BA- divide participants into two groups
- group 1: each participant does A then B
- group 2: each participant does B then A
- still a repeated measures design even though there are two groups of participants, because comparison will be made for each participant on their performance on the two conditions (morning and afternoon)
2. ABBA - all participants take part in each condition twice
- trial 1: condition A (morning)
- trial 2: condition B (afternoon)
- trial 3: condition B (afternoon)
- trial 4: condition A (morning)
- compare scores on trials 1 and 4 with trials 2 and 3 - as before also still a repeated measures design
- there are two ways to counterbalance order effects:
What is independent groups design?
Independent Groups Design - participants are placed in separate (independent) groups. Each group does one level of the IV; for example:
- Group A does the task with the TV on (one level of the IV)
- Group B does the task with no TV (the other level of the IV)
We compare the performance (DV) of the two groups
what are the advantages of independent groups design?
Avoids order effects (such as practice or fatigue) as people participate in one condition only. If a person is involved in several conditions, they may become bored, tired, and fed up by the time they come to the second condition or become wise to the requirements of the experiment!
what are the disadvantages of independent groups design?
The researcher cannot control the effects of participant variables (i.e. the different abilities or characteristics of each participant). For example, participants in Group A might happen to have better memories than those in group B. This would act as a confounding variable.
Independent groups design needs more participants than repeated measures design in order to end up with the same amount of data.
Method of dealing with limitation:
Randomly allocate participants to conditions which (theoretically) distribute participants variables evenly.
Random allocation can be done by putting the participants names in a hat and drawing out the names so that every other person goes in Group A
what are matched groups?
Matched Pairs - A compromise is to use two groups of participants but match participants on key characteristics believed to affect performance on the DV (e.g. IQ or time spent watching TV).
Then one member of the pair is allocated to Group A and the other to Group B. The procedure is then the same as for independent groups.
It is important to realise that the characteristics for matching must be relevant to the study. In other words you wouldn’t need to match participants on gender if you were testing memory - unless there was some evidence that gender was a potential confounding variable
what are the advantages of matched pairs?
Reduces participant variables because the researcher has tried to pair up the participants so that each condition has people with similar abilities and characteristics.
It avoids order effects, so counterbalancing is not necessary.
what are the disadvantages of matched pairs?
It is very time-consuming and difficult to match participants on key variables. The researcher probably has to start with a large group of participants to ensure they can obtain matched pairs on key variables.
It is not possible to control all participant variables because you can only match on variables known to be relevant, but it could be that others are important. For example, in a memory experiment you might match on memory abilities but later find that some of the participants have been involved in a teaching programme to boost memory skills and you should have matched on this.
Methods of dealing with the limitations:
Restrict the number of variables to match on to make it easier.
Conduct a piolet study to consider key variables taht might be important when matching.
what is the repeated measures design?
Repeated Measures Design - All participants receive all levels of the IV; for example;
- each participant does the task with the TV on, e.g. does a memory test
- then, perhaps a week later, each participant does a similar test without the TV on
We compare the performance (DV) of the participant on the two tests
what are the advantages of repeated measures design?
As the same participants are used in each condition, participant variables (i.e., individual differences) are reduced.
Fewer people are needed as they participate in all conditions (i.e., saves time).
what are the disadvantages of repeated measures design?
The order of the conditions may affect performance (an order effect). For example, participants may do better on the second test because of a practice effect or because they are less anxious. Alternatively, in some situations participants may do worse on the second test because of being bored with doing the same test again (boredom effect )
When participants do the second test they may guess the purpose of the experiment, which may affect their behaviour. For example, some participants may purposely do worse on the second tests because they want it to appear as if they work less well in the afternoon
methods for dealing with limitations:
Researchers may use two different tests to reduce a practice effect - though the two tests must be equivalent. This can be done by constructing a test of, say, 40 items and randomly allocating items to Test A and Test B.
The main way that order effects are dealt with is using counterbalancing.
In order to avoid guessing the aims of a study, a cover story can be presented about the purpose of the test.
What are the 4 types of experiments?
- laboratory experiment
- natural experiment
- field experiment
- quasi experiment
What is a lab experiment?
Laboratory experiment - an experiment that takes place in a controlled environment within which the researcher manipulates the IV and records the effect on the DV, whilst maintaining strict control of extraneous variables
What are the advantages and disadvantages of a lab experiment?
- High internal validity because extraneous variables can be controlled. This means that we can be confident that any observed change in the DV is due to the IV.
- reliable
- Participants usually aware that their behaviour is being studied. This leads participants to search for cues about the aims of the experiment and may affect the participants’ behaviour, reducing ‘realness’ (ecological validity)
- The IV or DV may be operationalised in such as way that it doesn’t represent everyday experiences i.e. it is low in mundane realism
- Low ecological validity can be experienced in terms of setting. Participants may feel uncomfortable in an unknown and artificial environment. This means they may not behave as they usually would.
What is a field experiment?
Field Experiments - an experiment that takes place in a natural setting within which the researcher manipulates the IV and records the effect on the DV
What are the advantages and disadvantages of a field experiment?
- Participants are not likely to be aware that their behaviour is being studied. This means they don’t respond to demand characteristics and therefore their behaviour may be more ‘natural’
- A field experiment takes place in a more natural setting, so participants can be more relaxed
- Many issues with lab experiments are the same for field experiments - may lack mundane realism - therefore not necessarily more like everyday life than lab experiments
- It is more difficult to control extraneous variables
- There is a major ethical issue - difficult to debrief participants if they don’t know that they are being studied
- more time consuming than lab experiments
What is a natural experiment?
Natural Experiment - an experiment where the change in the IV is not brought about by the researcher but would have happened even if the researcher had not have been there. The researcher records the effect of the DV
What are the advantages and disadvantages of a natural experiment?
- allows opportunities for research that may not otherwise be undertaken for practical or ethical reasons, such as the studies of institutionalised Romanian orphans
- high external validity, involve the study of real life issues and problems as they happen
- naturally occurring event may happen verry rarely, reducing opportunities for research
- participants may not be randomly allocated to experimental conditions (this only applies when there is an independent groups design). This means the researcher might be less sure whether the IV affected the DV
What is a quasi experiment?
Quasi-experiment - a study that is almost an experiment but lacks key ingredients. The IV has not been determined by anyone (the researcher or any other person) - the ‘variables’ simply exist, such as being old or young. Strictly speaking this is not an experiment.
What are the advantages and disadvantages of a quasi experiment?
- often carried out under controlled conditions and therefore share the strengths of a lab experiment
- like natural experiments, cannot randomly allocate participants to conditions and therefore may be confounding variables
- no manipulation of the IV - this means we cannot say for certain that the change measured in the DV was due to the IV (what do we call this?)
- unique participant characteristics - the sample could have unique characteristics meaning we can’t generalise the findings to other group of people (we call this low ecological or population validity)
what are the ways of dealing with extraneous variables in a lab or field experiment?
- single blind design - in this design, the participant is not aware of the research aims and/or of which condition of the experiment they are receiving
- ‘double blind design - in this design, the participant and the person conducting the experiment are blind to the aim/hypothesis
- experimental realism - if the researcher makes the task sufficiently engaging, the participant pays attention to the task and not the fact taht they are being observed
