research methods Flashcards
types of data
qualitative: experiences, detailed
quantitative: comparable, generalizable, simple data
independent variable
what we manipulate/change, different conditions
dependent variable
what we are measuring
true experiments (lab)
one IV and one DV, goal is to establish a cause-and-effect relationship between two variables, experiments are performed under highly controlled conditions
a research hypothesis
a clear, precise, testable statement that is written at the beginning of an investigation. it states the relationship between the variables being investigated
types of hypotheses
- null
- experimental/alternative: direction and non-directional
null hypothesis
IV will have no effect on the DV, any change will be due to chance
researcher’s goal is to reject the null hypothesis
directional hypothesis
expected direction that the results will go in can be predicted
non-directional hypothesis
cannot make a clear prediction, or if evidence is mixed. difference will be found but we dont know what it is
extraneous variables
variables that might interfere with the relationship between the IV and DV
determining cause-and-effect is threatened by EV’s
controls
something you do to minimize the possibility that an extraneous variable can affect your results
how to write a conclusion
- identify the relationship between the variables in the study
- identify the results
- apply this to the aim of the study
sampling methods
- self selected
- opportunity
- random
- stratified
secondary sampling techniques:
- purposive sampling: looking for people with a very specific set of traits
- snowballing sampling: type of purposive sampling used when looking for participants from a specific group which would not respond to an ad in a paper
external validity
when a study can be generalized to the target population
self-selected sampling
participants select themselves by volunteering
+quick and easy way to recruit individuals and have wide coverage
- not representative, share similar characteristics
random sampling
every member of the target population has an equal chance of being selected. takes into account all possible essential characteristics of the target population
+ easily generalizable, random sample of sufficient size is representative
- difficult to achieve with a larger population
opportunity (convenience) sampling
when you recruit participants that are more easily available
+quick, easy and cheap
- lack of representativeness, researcher bias
stratified sampling
sample that reflects the sub-groups within a target population
+ very representative
- time consuming
experimental designs
- repeated measures
- independent measures
- matched pairs
repeated measures
when the same group of participants takes part in both conditions of the IV
+ no participant variables
+ less participants needed
- order effect
independent measures
when you divide your participants into different groups that take part in different conditions of the IV
+ no order effect
- participant variable
- more people needed
matched pairs
when you split pairs of participants with similar characteristics into two different groups through matching tests
+ participant variables reduced
+ no order effects
- time consuming
- if one participant drops out you lose 2 data sets
- impossible to match people exactly
controlling for researcher and participant bias
- single blind
- double blind