vocab Flashcards
explanatory variable
the variable that is used to explain or predict the response variable
observational study
type of study in which individuals are observed or certain outcomes are measured. no attempt is made to affect the outcome (for example, no treatment is given)
stratum
part of the population which is being sampled
multistage sample
obtaining a sample from a population by splitting a population into smaller and smaller groups and taking samples of individuals from the smallest resulting groups
census
a study of every unit, everyone or everything, in a population
independent sample
samples that are selected randomly so that its observations do not depend on the values other observations
block design
the arranging of experimental units that are similar to one another in groups
paired sample
samples to make inferences about the differences between two paired variables, such as the effect of one treatment on two behaviors
placebo effect
when effects are seen in a group of people who did not actually receive a treatment
experiment
an ordered procedure which is performed with the objective of verifying, and determining the validity of the hypothesis
simple random sample
a subset of a statistical population in which each member of the subset has an equal probability of being chosen
bias
a subset of a statistical population in which each member of the subset has an equal probability of being chosen
quantitative data
measures of values or counts and are expressed as numbers
sample
a selection of data from a larger group of data
population
the pool of individuals from which a statistical sample is drawn for a study
cluster sample
a probability sampling method in which you divide a population into clusters, such as districts or schools, and then randomly select some of these clusters as your sample
stratified sample
divides the population into smaller groups, or strata, based on shared characteristics
convenience sample
choosing people who are easiest to reach
experimental unit
the individuals on which the experiment is performed, if they are people, they are subjects
factor
an explanatory variable that is manipulated to cause a change in the explanatory variable
treatment
a condition applied to the units is called a treatment
double blind
an experiment involving giving a medicine to subjects, neither the subject or the person giving the medicine does not know if the subject is getting the treatment or a placebo
matched pairs
a common form of blocking to compare two different treatments, it can be the same people getting the threat
replication
applying a treatment to a number of experimental units to see if the result occurs across a broad spectrum of experimental units, it is used to reduce the chance of random variation on the outcome measured
under coverage
occurs when some groups in the population are left out of the process of choosing the sample
non response
occurs when people who do not participate in a survey or study have different characteristics or opinions than those who do participate
statistically significant
the claim that a result from data generated by testing or experimentation is likely to be attributable to a specific cause
control
an experimental condition or element that is kept the same throughout the experiment, and it is not of primary concern in the experiment, nor will it influence the outcome of the experiment.
confounding
an unmeasured third variable that influences both the supposed cause and the supposed effect
dependent variable
a variable whose value depends on that of another
