What is a lab experiment
high controlled
iv manipulated
dv recorded
What are the strengths of a lab experiment
extraneous variables controlled , internal validity
easily replicated
weaknesses of lab experiment
reduced external validity
lack of mundane realism
What is a field experiment
manipulates iv in natural setting
Strengths of field experiment
higher external validity
less demand characteristics
weaknesses of field study
harder to control extraneous variables
ethical issues of informed consent
what is a natural experiment
naturally occurring iv
strength of natural experiment
high external validity
weaknesses of natural experiment
even less control over extraneous variables
p’s cannot be randomly allocated
what is a quasi experiment
iv based on an existing difference between people
strengths of quasi experiments
controlled
scientific credibility
weaknesses of quasi experiments
confounding variables as participants not randomly allocated
what is a naturalistic observation?
natural, non manipulated environment
high external validity
low control
What is a controlled observation
manipulated
more control
lower external validity
What is a covert observation?
participants are not aware they are being watched
truthful behaviour
ethical issues
what is an overt observation
participants do know and gives consent
ethically sound
participants may change behaviour
what is participants observation?
researcher takes part
greater insight
lose objectivity
what is non participant observation?
researcher doesn’t participate
remain objective
lack of extra insight
Strengths of questionnaires
potential large sample
easy to analyse responses
open or closed questions
weaknesses of questionnaires
response bias
social desirability bias
acquiescence bias
strengths of structures interviews
easily replicated
easy to analyse
weakness of structures interviews
inflexible
strengths of unstructured interviews
more depth
weakness of unstructured interview
difficult to repeat
weaknesses with interviews
participants may not be honest
What is a correlation?
measures relationship between two variables and the strength of that relationship
can be positive or negative
what is an aim?
driven by a theory to explain a given observation
what is a hypothesis?
makes predictions of an investigations outcome that makes reference to iv and dv
what is a null hypothesis
predicts no relationship will be found
What is random sampling
entire target population has an equal chance of being selected
strengths and weaknesses of random sampling
eliminates sampling bias
difficult to achieve
what is stratified sampling?
identifies different types of people in the target population and works out the proportions in order to be representative
strengths and weaknesses of stratified sampling
representative
time consuming
What is opportunity sampling
people available at the time
strengths and weaknesses of opportunity sampling
quick
could be biased
What is systematic sampling
every nth participant
strengths and weaknesses of systematic sampling
representative
difficult to achieve
strengths and weaknesses of volunteer sampling
volunteer bias
easy to achieve
what is primary data?
first hand from participants, collected specifically for that price of research
What is a pilot study?
small scale run of investigation
allows issues to be known
to modify design
determine number of participants needed
Strengths of repeated measures
subject variables reduced
better statistical tests
fewer subjects
weaknesses of repeated measures
order effects
demand characteristics
strengths of independent measures
order effects reduced
demand characteristics reduced
weaknesses of independent measures
worse statistical tests
more subjects
strengths of matched pairs
better statistical tests
order effects reduced
demand characteristics reduced
weaknesses of matched pairs
subject variables
time consuming
what are examples of observational design
event sampling
behavioural categories
time sampling
What is peer review
assessment of scientific work by others in the same field as you
objective
what are the measures of central tendency
mean
median
mode
what are the measures of dispersion
range
standard deviation
what is the mean
calculated by adding up all scores and dividing by number of scores
advantages
mean
takes all scores into amount so all data is represented
disadvantages
mean
when there is extreme scores , anomalies will distort the mean abs make it unrepresentative
what is the median
the middle value when placed in numerical order
advantages
median
unaffected by extreme scores
disadvantages
median
less sensitive than the mean as doesn’t take into account all of the scores
what is the mode
the value that occurs most frequently
advantage
mode
unaffected by anomalies
disadvantage
mode
unstable if only a few scores representing each value
what is the range
difference between highest and lowest score
advantage
range
easy and quick to calculate
disadvantage
range
vulnerable to rogue scores
what is standard deviation?
average amount all scores deviate from the mean
advantage
standard deviation
gives a more accurate picture than range
takes into account all scores and is sensitive
disadvantage
standard deviation
vulnerable to rogue scores
