Research Methods - 6 Flashcards
Phycological Research
- Research that underpins psychological explanations and is crucial to the scientific process.
- Suggest theories that revolve around human behaviour and test them using psychological investigations or studies
Types of variables
- Independent variable
- Dependent variable
- Extraneous Variables
- Situational variables
- Participant variables
Independent Variable
- Variable that is directly manipulated by the researcher to examine the effect
- Can have two or more levels (2 or more manipulations) - the variable can either be manipulated and altered several times under several tests
- To identify, find the factor being altered between tests/conditions
- must be operationalised - detailed and specific
Dependent Variable
- variable that is being measured
- Is affected by the manipulation of the independent variable
- outcome of the study
- to identify, find the factor being measured
- must be operationalised - detailed and specific
Operationalised
- detailed and specific
2. another researcher must know how to measure, change and manipulate an operationalised variable
Extraneous variable
- factors that may interfere with the IV and DV and affect the results
- Associated with conditions of the study or participants
- If it is not controlled and has an effect on the outcome it is called a confounding variable
Confounding variable
- type of extraneous variable
- confounds the result
- effects the result fo the effect of the IV is not seen or evident
Situational variable
- present in the environment of the investigation
- e.g. noise, distractions, light levels, and temperature
- may affect the outcome of the experiment if it is changed between tests (is not controlled)
- how the experiment was conducted can lead to situational variables: demand characteristics, investigator effects, order effects,
demand characteristics
- participants may change their behaviour to meet the aim of the study
- Investigator effects - researcher unintentionally gives participants clues on how to behave
Order Effects
Participants improve or change because the test needs to be repeated numerous times
Participant variables
- associated with the people participating in the experiment
- participants have different abilities and tendencies that influence the outcome of the study especially is one participant is found only in one condition of the experiment.
- e.g. physical ability, personality type, substance tolerance, life experiences, mood etc
Standardised procedure
where the procedure of a study is the same across all conditions
Controlling extraneous variables
- eliminate or control the variable
- most can be controlled but not eliminated
- removing the likelihood of extraneous variables occuring
Controlling situational variable
standardised procedure
Controlling order effects
- counter balancing - half of the participants experience the first condition first and the second half does the second condition first so improvement and decline in performance are balanced
- randomisation - same principle as counterbalancing but the decision of which condition is first is random
Controlling demand characteristics
- single-blind technique - participants are blind to the aim of the study and certain information is withheld so the behaviour is not changed
- double-blind technique - both the participants and investigators don’t know the aim of the study (controls demand characteristics encouraged by investigator effects
Controlling participant variables
- use the same participants for all conditions of the experiment so the data for each condition can be compared
- use different participants that are matched to important characteristics
- random allocation - participants are randomly assigned to different conditions so that results are in random distribution
Hypothesis
- Every study has a null hypothesis and an alternative (experimental) hypothesis
- Predicted outcomes of the study
- way it is written is dependent on what the experiment is looking for
Null hypothesis
- prediction that the result of outcome will have little to no effect
- “any difference will be due to chance” because it is unlikely that no difference will be found
Alternative (experimental) hypothesis
- Prediction of the expected outcome of a study based on a theory
- directional hypothesis, non-directional hypothesis, and experimental hypothesis
directional hypothesis
- if the theory makes a clear claim
- the expected direction that the results will go in
- shows correlation
- e.g. “adults will recall more digits than children”
non-directional hypothesis
- if the theory is unable to make a clear claim
- a difference or relationship will be found but des not state the difference of relationship
- e.g. “there will be a difference in the number of digits recalled by adults and children”
Experimental hypothesis
- used when a lab or field experiment is being carried out
Methods of sampling
- random sampling technique
- stratified sampling technique
- Volunteer sampling technique
- Opportunity sampling technique
Target population
- group of people that a study wishes to focus, study and apply the findings on
- a sample of the target population will be used to represent the target population
- Findings of the study has to be generalised to the target population
Sample
a selection of the target population that is directly studied in an investigation
generalisability
the extent to which the results of a study represent the whole population not just the sample used
sampling method
a technique used to gather a representative group of people as a sample from the target population
random sampling technique
- target population must be identified and all have an equal chance of getting chosen
- involves assigning every member with a number and drawing them e.g. lottery
- strength: should generate a representative sample as each member has an equal chance of getting chosen (helps control participant variables)
- weakness: even if randomly selected not everyone may agree to taking part leading to a less representative sample
- used to gather a random sample of participants from the target population
stratified sampling technique
- can be used if a target population is made up of different people and a researcher wants to replicate the experiment
- identifies the subgroups within the target population and takes a random sample from each to ensure they are all represented in the sample
- ensures subgroups of the target population are proportionately represented in a sample
- strength: useful if a small subgroup of the target population may be missed by using a random sampling technique and ensures that the sample is completely representative
- weakness: time-consuming and people may still refuse to take part which leads to a sample error and wrong conclusions being drawn
sample error
when a sample differs in qualities from the target population it intends to represent
biased sample
when the sample recruited is made up of a particular type of person which may not reflect the target population
Volunteer sampling technique
- involves gathering a sample of participants who are willing to volunteer themselves to take place in a study.
- advertising the study in adverts or a noticeboards that request volunteers to get in touch if they would like to participate
- strength: minimal effort for researches to identify and select a sample. It is possible to recruit from a target population by placing the advert in a specific location. It is also the most ethical sampling method because participants are not asked to participate directly and avoids putting pressure on people to participate
- weakness: less representative as not everyone in the target location will respond to the ad and can lead to a biased sample making the results unreliable
Opportunity sampling
- makes use of people who happen to be around at the time of the research
- Asking people to agree to take part os simply studying people who happen to be there without their agreement
- recruits participants who are readily available at the time
- strength: quickest and simplest sampling
- weakness: biased sample as not every member of the target population will be around at a time. The study is hard to replicate making it unreliable
Reliability
- consistency of an outcome which means that the same result is found again and again
- cannot trust results if they only found once
Validity
- extent to which a study measures what it intends to measure
Laboratory experiment
- takes place in a controlled experiment (artificial environment)
- researchers stage the conditions of the study and invite participants along
- Has an IV and a DV and the aim is to discover cause and effect between these variable
- useful for studies that need to isolate the IV and DV and exercise control
Field Experiment
- takes place in a natural environment
- has an IV that is manipulated by the researcher and a DV that is being measured
- Control over extraneous variables but not as much control as a lab experiment
- participants may or may not be aware they are taking part in the research
- useful when studying behaviour that needs to be seen and tested in a natural environment
Natural experiment
- occurs in a real-life environment
- has an IV and DV but the researchers are not manipulating the IV - it occurs naturally
- make use of naturally occurring situations
Types of research and experimental design
- Independent measures design
- Repeated measures design
- Matched pairs design
Research design
how participants are allocated to the conditions of a study
Experimental design
the name given to research design when used in an experiment
Independent measures design
- participants are split into groups with each group tested in only one condition of a study
- This is also known as independent groups design
- Sometimes this is the only design possible, if gender or age is the IV for e.g.
Repeated measures design
the same participants are used in all conditions of a study
Matched pairs design
- different participants are used in each condition of the study, but are matched for likeness on important characteristics
Strengths of independent measures design
no order effect as participants only take part in one condition of the study
Weaknesses of independent measures design
- more participants are needed than for a repeated measures design
- There may be individual differences between the groups (participants should be randomly allocated)
Pros of Repeated measures design
- Fewer participants are needed making it more economical
2. There are not individual differences between conditions of the study