Hawkes Statistics : 1.3 The Process of a Statistical Study
representative sample
A sample that reflects the characteristics of the population from which it is drawn. (does not favor one group from the population over another.)
What is the difference between case study and meta-analysis?
In contrast to a meta-analysis that looks at one variable over several studies, a case study looks at multiple variables that affect a single event.
placebo
a fake drug used in the testing of medication, HAS NO EFFECT. Placebo is given to participants to compensate for the placebo effect.
random sample
a sample that fairly represents a population because each member has an equal chance of inclusion
meta-analysis
a study that compiles information from previous studies.
explanatory variable
a variable that we think explains or causes changes in the response variable. think: WHAT HAPPENED TO our RESPONSE VARIABLE (our focus)). We usually have experimental control over this variable. It is usually what we have manipulated experimentally.
double-blind experiment
an experiment in which neither the experimenter nor the participants know which participants received which treatment
cross-sectional study
characterized by data that are collected at a single point in time.
convenience sample
choosing individuals who are convenient to reach
longitudinal study
data are gathered by FOLLOWING a particular group over a period of time.
Stratified sample
data gathered from a few members of each group
cluster sample
data gathered from each member of a few groups
simple random sample
every member of the population has an equal chance of selection
confounding variables
factors other than the treatment that cause an effect on the groups
experiment
generates data to help identify cause-and-effect relationships.
treatment group
group of subjects to which the treatment is applied
case study
looks at multiple variables that affect a single event.
observational studies
observes data that already exist.
systematic sample
obtained by selecting every nth individual from the population
Subjects
people or things being studied in an experiment.
randomize
refers to the practice of using chance methods (random number tables, flipping a coin, etc.)
replicate
repetition of an experimental condition so that the variability associated with the phenomenon can be estimated.
treatment
some condition that is applied to a group of subjects in an experiment. EX: asking one group of people in an experiment to take a vitamin.
control group
the group that does not receive the experimental treatment.
single-blind experiment
the people interacting with the subjects in the experiment know in which group each subject has been placed. (participants are unaware of which ppl have received the treatment and which have not)
placebo effect
the phenomenon in which the expectations of the participants in a study can influence their behavior
control
the standard by which the test results can be compared
response variable
the variable in an experiment that responds to the treatment. Response variable is what we have measured. Think: RV is our FOCUS in the experiment.