Research methods Flashcards
aim def
- a statement outlining why the psychologist is doing the research
- e.g “the aim is to discover/find out/see/investigate…”
hypothesis def
- a precise and testable statement of the relationship between two variables
- e.g “daycare makes children more aggressive than staying at home with a parent”
directional vs non directional hypothesis
- non directional refers to a difference in results without clarifying what the difference will be
- directional does say what the difference will be
independant variable def
variable that isn’t changed by other variables
dependant variable def
variable that depend on independant variable
extraneous variable def
any variable that you’re not controlling that can affect the dependant variable if not controlled
what is a control condition
a baseline for comparison
confounding variable def
a type of extraneous variable that not only affects the dependent variable, but is also related to the independent variable.
(like another independent variable)
how is a hypothesis operationalised
the independent variable is defined and how the dependent variable will be measured is stated.
E.g Not “intelligence” but “score on a IQ test” Not “memory” but “nimber of items recalled”
what is an experiment
where an experimenter holds all variables constant whilst systematically manipulating one.
what are the 4 types of experiment
lab, field, natural and quasi
lab experiment features
- take place in a controlled environment
- researcher controls the independent variable
- participants are randomly allocated to the conditions of the independent variable
field experiment features
- researcher controls the independent variable
- participants are randomly allocated to the conditions of the independent variable
- take place in a real world setting
natural experiments features
- independant variable is not controlled/ manipulated by the experimenter, but is naturally realised
quasi experiment features
- IV is based on existing difference between people (e.g. age, gender, ethnicity, presence of mental disorder).
- Noone has manipulated this - it simply exists and cannot be changed.
why is random allocation important
evenly distributes participant characteristics across the conditions of the experiment
what is standardisation
using exactly the same formalised procedures/ instructions for all participants in a study
why is standardisation important
so that non-standardised changes in procedure do not act as extraneous variables
what is randomisation
the use of chance methods to control for the effects of bias when designing materials and deciding the order of experimental conditions
(E.g Allocating participants to tasks, selecting samples of participants, and so on, should be left to chance as far as possible, to reduce the investigator’s influence on a study.)
why is randomisation important
controls investigator effects
what are demand characteristics
cues from the researcher/ situation that may reveal the purpose of the investigation to participants. this may change the participants behaviour
what are investigator effects
researchers unconscious biases when designing an investigation
what is a single blind experiment
where only the researcher doing the study knows which treatment/ intervention the participant is receiving. reduces demand characteristics
what is a double blind experiment
where neither the participant or experimenter knows who is receiving a particular treatment. reduces demand characteristics and investigator effects
what are the 3 types of experimental design
independent groups, repeated measures and matched pairs
what are independent groups
- participants are allocated yo different groups where each group represents an experimental condition.
- they don’t know what is being measured
what are repeated measures
all participants take part in all conditions of the experiment
what are matched pairs
- pairs of participants are first matched on some variables that may affect the dependant variable
- one member of the pair is assigned to condition a and the other to condition b
what are the sampling methods
random, systematic, stratified, opportunity and volunteer
what is random sampling
random- equal chance of being selected
what is systematic sampling
e.g selecting every 5th, 7th, 10th person
what is stratified sampling
looking at each subgroup which reflects proportions in society
e.g 60% males, 40% females in experiment, if this reflects the situation
what is opportunity sampling
selecting people who are most easily available at the time of the study
what is volunteer sampling
inviting people to take part
Quantitative data
-numbers
-easier to draw conclusions but less detail
Qualitative data
-words
-richer info: more detail + more valid
- difficult to analyse
Primary data
Collected specifically for the purpose of the experiment. Comes first hand from participants.
Secondary data
Data that has been collected before the current research by someone else. It is used in meta-analysis (when a number of studies collected for a similar purpose are pooled together and a conclusion is drawn)
What is publication bias
- A bias on what is published based on the direction/ strength of study findings.
- It may lead some researchers to manipulate their results to ensure statistically significant results. One example of this is resorting to data dredging, or running statistical tests on a set of data until something statistically significant happens.
Strengths + weaknesses of correlational analysis
Strengths: easy starting point to suggest what should be researched again
Weakness: don’t show cause or effect. Can be misinterpreted
Pro/con of mean
Pro: included all data, so is representative
Con: can be distorted by anomalies
Pro/con of median
Pro: not distorted by anomalies
Con: doesn’t include all data