14.7 Intro to Statistical Thinking

Common confounding factor

A(n) ________ is the placebo effect, in which patients who think they are receiving a medication report an improvement (perceived or actual), even though the "treatment "they received was a placebo- a simulated or false treatment (sometimes called a "sugar pill)

Nonresponse

________ bias, in which individuals with a common characteristic are unwilling (or neglect) to respond to a questionnaire.

Statistical thinking

In ________, we expect a random sample to share approximately the same properties as the population.

Confidence level

The 95 % ________ means that there is less than a 5 % chance (or 0.05 probability) that the result obtained from the sample could be obtained by chance alone.

Sample

A(n) ________ is any subset of the population.

Statistical conclusions

________ are based on probability and are always accompanied by a confidence level.

Extraneous

________ or unintended variables that systematically affect the property being studied are called confounding variables.

Survey sampling

In ________, data are collected through responses to questionnaires.

Entire population

In statistical thinking, we make judgments about a(n) ________ based on a sample.

Two variable data

In statistics, a question of interest when studying ________ is whether or not the correlation is statistically significant.

Little correlation

If r is close to zero, the variables have ________.

Simple random sample

A(n) ________ is one in which every individual in the population has the same probability of being selected.

bird watchers

In observational studies, data are collected by observation (such as when ________ make their traditional Christmas bird count)

Random sample

A(n) ________ is one that is selected arbitrarily and without bias.

importance of randomness

In selecting a sample, the ________ can not be overemphasized.

In an experimental study, two groups are selected

a treatment group (in which individuals are given a treatment) and a control group (in which individuals are not given the treatment)