Research Methods (experimental) Flashcards
What are the features of science in psychology?
(F.O.R.E)
1. falsifiability
2. objectivity
3. replicability
4. empirical method
what does falsifiability mean?
the possibility that a statement or hypothesis can be proved wrong
what does objectivity mean?
measurement of data is not affected by the expectations of the researcher
what does replicability mean?
recording procedures carefully for another researcher to repeat them and verify the original results
What is meant by the empirical method?
Methods of gaining knowledge that rely on direct observation or testing (not hearsay or rational argument)
What is a paradigm?
a shared set of assumptions about a subject matter of a discipline and the methods appropriate to its study
what is a paradigm shift?
Progress within an established science occurs when there is a scientific revolution. A handful of researchers begin to question the accepted paradigm, and this opposition gathers pace and popularity, and eventually a paradigm shift occurs when there’s too much contradictory evidence to ignore
what is hypothesis testing?
To make a clear and precise prediction based on a theory, a hypothesis should be tested using systematic and objective methods to determine whether it should be supported or rejected.
What is a laboratory experiment?
A lab experiment takes place in a controlled environment where variables can be easily manipulated.
Participants are aware that they are taking part in an experiment but may not know its true aims
What are the advantages and disadvantages of a lab experiment?
Advantages:
- controlled variable
- high internal validity
- easy to replicate
Disadvantages:
- pps might act abnormally
-low ecological validity
-demand characteristic
What is a field experiment?
An experiment that happens in a natural/ordinary environment, the independent variable is deliberately manipulated by the researcher and measures the DV, participants are usually aware they are participating
What are the advantages and disadvantages of field experiments?
advantages:
-high ecological validity
-lack of demand characteristics
disadvantages:
-low internal validity
-less easy too replicate
What is a natural experiment?
An experiment that is conducted when it is not possible for ethical or practical reasons to manipulate the IV (the IV occurs naturally)
What are the advantages and disadvantages of a natural experiment?
advantages:
- allows research where the IV can not be manipulated
- high ecological validity
disadvantages:
-lack of casual relationship
-lack of random allocation
What is a quasi-experiment?
A quasi-experiment is where the IV varies naturally between people, but the DV is still measured
what are the advantages and disadvantages of a quasi-experiment?
advantages:
- allows comparisons between types of people
- can be carried out in a lab
disadvantages:
- may be carried out in a lab
- lack of random allocation
What is an independent variable?
the variable that is manipulated (changed)
What is a dependent variable?
the variable that is being measured
What is an extraneous variable?
anything other than the IV that might affect the DV. These variables can be controlled by the researcher.
e.g: age of pps, time limits for tasks, content of word lists
What is a confounding variable?
Variables that aren’t controlled for in an experiment - which do affect the results (ruin them)
e.g: weather, mood of the pps, personalities & individual differences
what are research aims?
the stated intentions of what questions are planned to be answered
what is a hypothesis?
a formal, unambiguous statement of what is predicted. It must contain both conditions of the IV & the expected outcome of the DV, be operationalised and measurable
what is a directional hypothesis?
states whether the DV outcome is expected to be greater or lesser, positive or negative, and it is used when there has been previous research to suggest a direction
what is a non-directional hypothesis?
doesn’t state the direction of the DV, just that there will be a difference
It is used when there is no previous research or it is contradictory
what is a null hypothesis?
a prediction of no difference between between the two IV conditions on the the outcome of the DV
what is internal reliability?
each participant in a study is treated the same way
what is external reliability?
same/similar results are found after repeated tests
what are the assessments of reliability?
- Test-retest reliability (external): test the same person twice
- interobserver reliability (external): compares observations from different observers
- measured using a correlation (should exceed +0.8)for reliability
how do you improve reliability?
repetition of study (check results over again)
what is internal validity?
a measure of whether results obtained are solely affected by changes in the variable being manipulated (i.e., by the independent variable) in a cause-and-effect relationship
what is external validity?
how far you can generalise the results of a study in relation to other settings, situations or individuals
what is ecological validity?
a type of external validity that measures the extent to which the findings can be generalized to a real-life setting
what is population validity
at type of external validity which measures whether or not the sample of people that participated in the study are representative of the general population
what is temporal validity?
at type of external validity that measures if the results of a study will generalise across time
what are the assessments of validity?
- face validity: whether it looks like it measures what it should measure
- concurrent validity: whether findings are similar to those on a well established test
how do you improve validity?
minimizing measurement by increasing the length of the assessment
summarise independant groups
- recruit a group of pps
- divide them into two
- one group does the experiment with the IV set to condition one
- the other does the task with the IV set to condition two
- measure the DV for each group
6.compare the results for the two groups
what are the advantages of independent groups?
- no order effects
- no demand
characteristics - no carry over effects
- no transfer of knowledge
what are the disadvantages of independent groups?
- recruiting pps
- sample size
- unfair playing field
- less cost effective
summarise repeated measures
- recruit a group of pps
- the group does the experimental task with the IV set for condition 1
- the group repeats the experimental task with the IV set for condition 2
- compare the results from the two conditions
what does counter balancing a repeated measures mean?
half of the group does condition A followed by condition B, the other half does B followed by A (ABBA)
what are the advantages of repeated measures?
- fewer subjects
- greater statistical power
- evaluate results over time
- detect within person change
- more control over confounding variables
what are the disadvantages of repeated measures?
- order effect
- fatigue
- carry over effects
- lower internal validity
- hidden effects
summaries matched pairs
- recruit a group of pps
- find out what sort of people you have in the group
- recruit another group that matches relevant characteristics (e.g: IQ)
- treat the experiment as independent measures
- compare the results for the matched pairs
what are the advantages of matched pairs?
- reduce error variability
- increases statistical power
-reduces sample size - increases internal validity
-more efficient use of resources
what are the disadvantages of matched pairs?
- time consuming
- lost data
- imperfect matches
- economic disadvantages
- smaller sample
what are demand characteristics?
cues that might indicate the study aims to the pps
what are investigator effects?
when the researcher unintentionally influences the outcome
how can investigator effects and demand characteristics be avoided?
- single blind = pps aren’t aware of the aims till the end
- double blind = neither the pps or the researcher is aware of the aims till the end
what is a control group?
used as a comparison or base line
what is a confederate?
(research actors) employed pps
why is random allocation to conditions important?
decreases systematic errors so individual differences are less likely to effect results
what is randomisation?
the process of randomly assigning subjects to a group using a random method to avoid order effects
e.g: flipping a coin/ name out a hat
what is standardisation?
keeping everything the same for all pps so the investigation is fair
what is a pilot study?
check procedures and techniques, make appropriate changes
why are pilot studies carried out
to identify potential issues and modify the experiment
what are the advantages of carrying out a pilot study?
- reduce risk of errors
- saves time and resources
what is opportunity sampling?
researcher asks who is around at the time of the research
what are the advantages of opportunity sampling?
what are the disadvantages of opportunity sampling?
what is random sampling?
obtaining a list of all the members of a target population all names are assigned a number and randomly picked
advantages of random sampling
disadvantages of random sampling
