6, Foundations: Methods and Approaches Flashcards
experiment
- investigation looking for cause and effect
- changes a variable (the cause) and measures how it will affect another variable (the effect)
- only empirical way to prove causation
independent variable
“cause” variable. gets manipulated in an experiment, it affects the dependent variable
dependent variable
“effect” variable. Changes based on the value of the independent variable
control variable
a constant variable in an experiment, should not change even if the independent does
population
group of interest for study
representative sample
a sample from a population to represent the population. Used because populations are often too big to study
representativeness
degree to which the sample reflects the characteristics of the population it is drawn from
experimental group
the group receiving/reacting to the independent variable
control group
the group that doesn’t receive the independent variable but is to be kept identical to the experimental group in all other respects
random sampling
sampling random people from a population
randomly assigned
randomly dividing the representative sample into the experimental and control group
biases
factors that skew the representativeness of a given sample
hindsight bias
I-knew-it-all-along bias
bias of selection
when random sampling is done based on a specific physical space
if you wanted to conduct a survey based on all college students on a campus, you wouldn’t stand in the quad and interview people that walk by because you wouldn’t be representing the students that don’t have classes right now, therefore not random
self-selection bias
when people being studied have control over whether or not they participate in the experiment
highly opinionated people will be more likely to fill out a survey, skewing results
pre-screening/advertising bias
- common in medical research
how volunteers are screened or the experiment is advertised may skew the sample
if a researcher is advertising a treatment that helps to quit smoking, they will receive volunteers who may well have quit smoking on their own anyway
healthy user bias
when the sample is in better shape than most of the rest of the population of study
single-blind design
only subjects do not know whether they are in the control or experimental group
double-blind design
neither subject nor researcher knows who is in the experimental or the control group
- generates more pure results because the researcher cannot inadvertently reveal to the groups which group they are in
placebo
seemingly therapeutic object/procedure that causes the control group to believe that they are in the experimental group
correlational research
determining degree of association between two or more variables that can occur naturally
confounding/third/extraneous variable
an unknown factor playing a role in the experiment
surveys
a tool of correlational studies
either interviews or questionnaires, used to accumulate vast amounts of data to study variable relationships
often used for voter characteristics, criminal behavior, teen alcohol and drug use
longitudinal studies
study over long period of time with few subjects
cross-sectional studies
study to test wide array of subjects from different backgrounds so the study is more general
clinical research
medical research on human subjects