Stats Ch. 1 & 2 Vocab

Front 1

Descriptive Statistics

Back 1

Numerical, graphical and tabular methods for organizing and summarizing data

Front 2

Population

Back 2

Entire collection of individuals or measurements about which information is desired

Front 3

Sample

Back 3

A part of the population selected for study

Front 4

Categorical data

Back 4

Individual observations are categorical responses (nonnumerical)

Front 5

Numerical data

Back 5

Individual observations are numerical (quantitative) in nature

Front 6

Discrete numerical data

Back 6

Possible vaus are isolated points along the number line

Front 7

Continuous numerical data

Back 7

Possible values form an entire interval along the number line

Front 8

Bivariate / Multivariate data

Back 8

Observations consist of two (bivariate) or more (multivariate) responses or values

Front 9

Frequency distribution for categorical data

Back 9

Table that displays frequencies (or relative frequencies) for each of the possible values of a categorical variable

Front 10

Bar chart

Back 10

A graph of a frequency distribution for a categorical data set; each category represented by a bar, and area of the bar is proportional to the corresponding frequency or relative frequency

When to use: categorical data
What to look for: frequently and infrequently occurring categories

Front 11

Dotplot

Back 11

A picture of numerical data in which each observation is represented by a dot on or above a horizontal measurement scale

When to use: small numerical data sets
What to look for:
-Representative/typical values in the data set
-Extent to which the data values spread out
-Nature of the distribution of values along the number line
-Presence of unusual values in the data set

Front 12

Data Analysis Process

Back 12

1. Understand nature of the problem
2. Decide what to measure and how to measure it
3. Data collection
4. Data summarization and preliminary analysis
5. Formal data analysis
6. Interpretation of results

Front 13

Inferential statistics

Back 13

Branch of statistics that involves generalizing from a sample to the population from which it was selected and assessing the reliability of such generalizations

Front 14

Relative Frequency

Back 14

Fraction or proportion of the observations resulting in the category

Relative freq = frequency/ number of observations in the data set

Front 15

Observational study

Back 15

A study that observes characteristics of one or more existing populations; goal is to draw conclusions about corresponding population or show differences between 2+ populations

Front 16

Experiment

Back 16

A procedure for investigating the effect of experimental conditions (which are manipulated by the experimenter) on a response variable

Front 17

Simple random sample

Back 17

A sample selected in a way that gives every different sample of size n an equal change of being selected

Front 18

Stratified sampling

Back 18

Dividing a population into subgroups (strata) and then taking a separate random sample from each stratum

Front 19

Cluster sampling

Back 19

Dividing a population into subgroups (clusters) and forming a sample by randomly selecting clusters and including all individuals or objects in the selected clusters in the sample

Front 20

1 in k systematic sampling

Back 20

Sample selected from an ordered arrangement of a population by choosing a starting point at random from the first k individuals on the list and then selecting every kth individual thereafter

Front 21

Confounding variable

Back 21

A variable that is related both to group membership and to the response variable

Front 22

Measure or response bias

Back 22

The tendency for samples to differ from the population because the method of observation tends to produce values that differ from the true value

Front 23

Selection bias

Back 23

The tendency for samples to differ from the population because of systematic exclusion of some part of the population

Front 24

Nonresponse bias

Back 24

The tendency for samples to differ from the population because measurements are not obtained from all individuals elected for inclusion in the sample

Front 25

Treatments

Back 25

The experimental conditions imposed by the experimenter

Front 26

Extraneous factor

Back 26

Variable that is not of interest in the current study by is thought to affect the response variable

Front 27

Direct control

Back 27

Holding extraneous factors constant so that their effects are not confounded with those of the experimental conditions

Front 28

Blocking

Back 28

Using extraneous factors to create experimental groups that are similar with respect to those factor, thereby filtering out their effect

Front 29

Randomization

Back 29

Random assignment of experimental units to treatments or of treatments to trials

Front 30

Replication

Back 30

A strategy for ensuring that there is an adequate number of observations on each experimental treatment

Front 31

Placebo effect

Back 31

A treatment that resembles the other treatments in an experiment, but that has no active ingredients

Front 32

Control group

Back 32

A group that receives no treatment or one that receives a placebo treatment, used to compare to experimental group

Front 33

Single-blind experiment

Back 33

An experiment in which the subjects don't know which treatment they received but the individuals measuring the response do know which treatment was received, or an experiment vice versa

Front 34

Double-blind experiment

Back 34

An experiment in which neither the subjects nor the individuals who measure the response know which treatment was received

Front 35

Census

Back 35

A study that obtains information from an entire population

Front 36

Sampling w/o Replacement

Back 36

Once an individual from the population is selected for inclusion in the sample, it may not be selected again in the sampling process

Front 37

Sampling w/ Replacement

Back 37

After an individual from the population is selected for inclusion in the sample and the corresponding data are recorded, the individual is placed back in the population and can be selected again in the sampling process

Front 38

Convenience Sampling

Back 38

Using an easily available or convenient group to form a sample

Front 39

Voluntary Response Sampling

Back 39

Samples rely entirely on individuals who volunteer to be a part of the sample; extremely unlikely that individuals participating are representative of any larger population of interest

Front 40

Design

Back 40

The overall plan for conducting an experiment

Front 41

What are the 4 key concepts in designing an experiment?

Back 41

1) Randomization

2) Blocking

3) Direct Control

4) Replication