Research Methods Flashcards
Alternative Hypothesis
Predicts a relationship between the IV and the DV
(there will be a difference…)
Null hypothesis
Predicts no correlation or difference between the IV and the DV. Any relationship will be due to chance alone.
One-tailed Hypothesis
Directional
Two-tailed Hypothesis
Non-directional
Laboratory Experiment
An experiment conducted in a researcher-controlled environment
Field Experiment
An experiment conducted in a participants natural environment
What are the three experimental designs?
independent groups
repeated measures
matched pairs
natural experiment
an experiment that investigates a naturally-occurring IV
Pros of lab experiments
can determine causality
can control extraneous variables
cons of lab experiments
low ecological validity
demand characteristics
pros of field experiments
high ecological validity
no demand characteristics
cons of field experiments
ethical issues (consent)
can’t determine causality
can’t control extraneous variables
pros of independent groups
no order effects
less demand characteristics
cons of independent groups
individual differences (participant variables)
more ppts to recruit (compared to repeated measures)
pros of repeated measures
no individual differences
less ppts to recruit (than matched pairs and independent groups)
cons of repeated measures
order effects
demand characteristics
pros of matched pairs
no individual differences
no order effects
less demand characteristics
cons of matched pairs
more ppts to recruit (than repeated measures)
time consuming —> ppt retention
what is nominal measurement?
- the number of ppts falling into various categories (eg. big-small, man-woman)
- ppts can only belong to one category at a time (can move from one to the other)
what is ordinal measurement?
- can be numbers or words
- can be placed in rank order (hot, hotter, hottest)
- data has unequal intervals (may be based on personal interpretation)
- categories are subjective
what is interval measurement?
- scores are on a linear scale (like ordinal, rank order)
- data has equal intervals (can only be numbers)
- categories are objective
what is ratio measurement?
- has equal intervals
- has real zero (scale starts at zero, although may not be possible to score)
- examples: height, cm, kg, bpm
what is a type one error?
- the level of significance is too lenient
- a true null hypothesis is rejected
what is a type two error?
- the level of significance is too stringent
- false null hypothesis is accepted
what is research validity?
whether or not the research is testing what it claims to be testing
- external: findings are generalisable to other situations
- internal: the extent to which the experiment measured what it set out to
what is research reliability?
the consistency of the reasearch
- external: consistency of results when related on same ppts over period of time and on other ppts
- internal: consistency within research
what is inter-rate reliability?
scores of two or more of the research team are compared for consistency (eg. 8/10 match is 80% inter-rate reliability)
(internal reliability)
what is the split half method?
question is asked in first half of test, repeated in second half with different wording (should produce same result)
(internal reliability)
what is test re-test?
same test is administered twice at two different points of time; compared for consistency with statistical analysis; should be no significant difference in results
(external reliability)
what is face validity?
intuitive measurement - do the findings and conclusions make sense?
(internal validity)
what is content validity?
content of a test represents area of interest (involves bringing in an expert of the field)
what are the sections of a psychological report?
- abstract
- introduction
- method
- results
- discussion
- references
- appendices
what is a CAT scan?
- computed axial tomography
- series of x-rays combined to make a 2-or-3 dimensional picture of scanned area
- dye often injected into patient
what are the pros of a CAT scan?
- reveal abnormal structures in the brain (eg. tumours)
- higher image quality than traditional x-rays
what are the cons of a CAT scans?
- requires more radiation than traditional x-rays
- only provides structural information
what is an MRI scan?
- magnetic response imaging
- use of magnetic field (brain atoms change alignment when radio is on, emit radio signals when off)
- signals read by detector, brain structure is mapped
what is a functional MRI (fMRI)?
provides anatomical and functional information - repeated images taken of brain in action
what are the pros of MRI’s?
- more detailed image of brain soft tissue (than CAT)
- less radiation; suited for when examination must be undergone several times
what are the cons of MRI’s?
- takes a long time
- can be uncomfortable for patients
what are PET scans?
- positron emission tomography
- slightly radioactive glucose administered to patient
- brains most active areas use glucose; radioactive areas of brain detected, created a picture of brain activity
- between 10-40 minutes and is painless
what are the pros of PET scans?
- reveals otherwise unavailable chemical information
- shows brain in action
what are the cons of PET scans?
- costly; not easily available for research
- patient must be injected with radioactive substance; can only be used a few times
- less precise than MRI
what is the IV?
independent variable - what we manipulate
what is the DV?
dependent variable - what we measure
what are co-variables?
related variables
what is the correlation co-efficient?
the statistical significance of a correlation
what are extraneous variables?
- may affect the IV, participants are affected differently
- should be controlled or eliminated
what is an experiment?
where the IV is manipulated (by the researcher)
what is a naturalistic observation?
takes place in ppts natural environment
what is a controlled observation?
takes place in an artificial setting
what is a covert observation?
ppts unaware of observation
what is an overt observation?
ppts aware of observation
what is a ppt observation?
researcher/observer is involved in situation being observed
what is non-ppt observation?
researcher/observer not involved in situation being observed
what is event sampling?
recording how many times a particular event occurs
what is time sampling?
behaviour is recorded at regular intervals
what is content analysis and what is it used for?
- it is the analysis of qualitative data
- it is used to turn qualitative data into quantitative data
what is a questionnaire?
a standardised list of questions given to ppts
what is a structured interview?
composed of standardised, pre-set questions
what is an unstructured interview?
has spontaneous, unstructured discussion
what are the pros of content analysis?
- easy, quick
- allows statistical analysis due to production of quantitative data
what are the cons of content analysis?
- cannot determine causally
- cannot draw conclusions
what is a correlational study?
the study of a systematic association between two continuous variables
what is a case study?
detailed investigations into a person, group of people or event
what are the pros of case studies?
- produces detailed qualitative data
- allows for otherwise impractical or unethical investigations
what are the cons of case studies?
- low ecological validity
- researcher bias
what is a longitudinal study?
research conducted over a long period of time (in order to observe long-term effects)
what are the pros of longitudinal studies?
- controls ppt variables
- can study change in a person over a period of time
what are the cons of longitudinal studies?
- attrition (samples can end up biased or too small)
- order effects and demand characteristics
- expensive
what is a cross-sectional study?
study involving groups of people who do not share the variable of interest, but do share other relevant variables (studies cross-sections of society)
what is a self-report method?
ppts provide information about themselves
what are the pros of online research?
- reach a wide range of people
- quick and easy
what is a con of online research?
- cannot confirm information offered—> potentially skewed results (cannot guarantee validity of results)
what is a target population?
the population you wish to research/pull your sample from
what is a sample population?
the people you have in your sample (from your target population)
what is random sampling?
each ppt has an equal chance of selection/is chosen randomly
what is a pro of random sampling?
- unbiased (each ppt has equal chance of selection)
what are the cons of random sampling?
- can be time-consuming (must list all target population)
- can be a non-representative sample (by chance)
what is systematic sampling?
the use of a pre-determined system to select ppts (form of random sampling)
what is a pro of systematic sampling?
- unbiased (selection made with objective system)
what are the cons of systematic sampling?
- starting number must be randomly selected before interval is applied for true non-bias
- may be non-representative (by chance)
- time-consuming
what is opportunity sampling?
the recruitment of those either most available or most convenient
what are the pros of opportunity sampling?
- efficient
- not time-consuming (quick)
what is a con of opportunity sampling?
- biased (sample drawn from small part of target population)
what is stratified sampling?
ppts are randomly recruited from strata in proportion to their occurrence in the target population
what is a pro of stratified and quota sampling?
- more representative than other methods
what is a con of stratified sampling?
- time-consuming
what is quota sampling?
ppts are recruited from strata using a non-random method in proportion to their occurrence in the target population
what are the cons of quota sampling?
- time-consuming
- more likely to be biased (than stratified)
what is self-selected/volunteer sampling?
ppts volunteer to take part (recruited from an advertisement)
what are the pros of self-selected/volunteer sampling?
- access to variety of ppts
- more representative (than opportunity)
what is a con of self-selected/volunteer sampling?
- volunteer bias
what is snowball sampling?
current ppts recruit further ppts (from among people they know), and so on
what is a pro of snowball sampling?
enables researchers to recruit difficult-to-access groups of people
what is a con of snowball sampling?
- sample likely to be non-representative (unlikely to be good cross-section of society, made up of friends-of-friends)
what group does mean, median and mode belong to?
measures of central tendency
what group does range and standard devotion belong to?
measures of dispersion
what is the pro of using the mean?
- more representative (uses all data)
what is a con of using the mean?
doesn’t take into account anomalies/is affected by extreme values
what is a pro of using the median?
isn’t affected by extreme values
what is a con of using the median?
not as precise or representative (as the mean) (only takes into account one or two values)
what is a pro of using the mode?
easy to calculate
what are the cons of using the mode?
- could be bi or tri modal (tells us nothing about the average)
- may not be a mode
what is the definition of standard deviation?
variation of data around the mean
what is a pro of standard deviation?
takes into account all data (precise and representative)
what is a con of standard deviation?
more complex to calculate
when is a bar chart used?
when data is in categories
when is a pie chart used?
to show relative sizes of data
when is a line graph used?
to show information that is connected (eg. a change overtime)
when is a scatter graph used?
to show the association between two variables (calculates correlation coefficient)
what is construct validity?
demonstrating the extent to which performance on a test measures an identified underlying construct
- involves deconstructing the term we wish to investigate to better understand, and therefore, measure it
What are confounding variables?
- any variable that is not the IV but affects the DV
- can’t be taken away, so must be controlled
