CH1 - The Nature of Statistics

Methods for organizing and summarizing information

descriptive statistics

Collection of all individuals or items under consideration in a statistical study

population

Part of the population from which information is obtained

sample

Methods for drawing and measuring the reliability of conclusions about a population based on information obtained from a sample of the population

inferential statistics

True or false: The sample will always be bigger than the population

false; the sample derives from the population so it will never exceed the population size

Descriptive or inferential: no inferences are drawn from the data

descriptive

Descriptive or inferential: inferences are drawn from the data

inferential

Descriptive or inferential: the fact that Truman-Barkley got 49.7% of the votes in that tally then that represents the fact that 49% of the voters represented for him nationwide

inferential; drawing inferences about the data

A sampling procedure for which each possible sample of a given size is equally likely to be the one obtained

simple random sampling

A sample obtained by simple random sampling

simple random sample

What are the 2 types of simple random sampling?

with replacement (SRSWR) and without replacement (SRS)

In a designed experiment, the individuals or items on which the experiment is performed

experimental units

Two or more treatments should be compared

control

The experimental units should be randomly divided into groups to avoid unintentional selection bias in constituting the groups

randomization

A sufficient number of experimental units should be used to ensure that randomization creates groups that resemble each other closely and to increase the chances of detecting any differences among the treatments

replication

The characteristic of the experimental outcome that is to be measured or observed

response variable

A variable whose effect on the response variable is of interest in the experiment

factor

The possible values of a factor

levels

For one-factor experiments, it is the levels of the single factor

For multifactor experiments, it is a combination of levels of the factors

treatment

All the experimental units are assigned randomly among all the treatments

completely randomized design

The experimental units are assigned randomly among all the treatments separately within each block

randomized block design