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.