AP Psychology: Research Methods

experiment

a research method where you manipulate the environment to isolate the cause and effect of something

hypothesis

testable prediction

operational definition

clear definition of variables in experience that is precise, objective, and measurable.

created in order to have a high inter-rater reliability (multiple people agree on behavior being tested)

independent variable

factor being manipulated in experiment

variable whose effect is being studied

dependent variable

outcome that is measured

variable that may change when independent variable is manipulated- depends on IV

control group

group in experiment that does not receive treatment

experimental group

group in experiment being exposed to treatment

experimenter bias

when a researchers beliefs influence the outcome of a study

double-blind procedure

both research participants and staff unaware of whether participants received treatment or not

used to reduce experimenter bias

placebo

substance/intervention that has no real effect but is used to mimic the real treatment

placebo effect

when a person’s expectations alone influence how they feel

hindsight bias

tendency to believe, after learning an outcome, that one would have forseen it

Hawthorne Effect

when a person changes their behavior because they know they are being watched/studied

can lead to improved performance/productivity

random sampling

subjects randomly chosen from a larger population to be part of a study, representative of population

everyone has an equal chance of getting in

process of getting people into a study

random assignment

how a sample is split into two groups

ensure groups are comparable and balanced

sampling bias

when sample is not representative of population

confederate

a person who is part of the experiment but the subject doesn’t know it

construct validity

extent to which a test accurately measures what it is testing

predictive validity

how well a test predicts future outcomes

test-retest reliability

whether the study yields the same results on repeated measures

inter-rater reliability

extent to which multiple opinions agree on assessment

case study

an in-depth analysis of individual/group in attempt to reveal universal principals

unique instances

naturalistic observation

observing behavior in naturally occurring situations without manipulating situation

correlational study (survey)

obtaining self-reported attitudes/behaviors of a particular group by questioning a representative

easy to fall to sampling bias

self-report distortion

inaccurate representation of ones behaviors

could be due to social desirability bias

Institutional Review Boards

committee that reviews research done to humans to ensure that it is ethical and safe

debriefing

telling subjects what they did in the experiment once they are finished

informed consent

subject agrees to be in experiment, knows what they are getting self into

positive correlation

as one factor increases, so does the other

negative correlation

as one variable increases, the other decreases

statistical significance

how likely it is that an obtain result occurred by chance

indicates that there is a relationship between variables

median

middle value in data set

mean

arithmetic average

mode

most prevalent data piece

variability

the degree to which data point in a data set differ from each other

normal distribution

symmetrically distributed data with no skew

negatively skewed distribution

peak at end of graph

mean < median

positively skewed distribution

peak at beginning of graph

mean > median