Statistics Chapter 1

Front 1

Data

Back 1

Collectionsofobservations,such as measurements, genders, or survey responses

Front 2

Statistics

Back 2

Thescience of planning studies and experiments, obtaining data, and thenorganizing, summarizing, presenting, analyzing, interpreting, and drawingconclusions based on the data

Front 3

Population

Back 3

Thecomplete collection of all measurements or data that arebeing considered

Front 4

Census

Back 4

Collectionof data from everymember of a population

Front 5

Sample

Back 5

Subcollectionof members selected from a population

Front 6

Prepare - Context

Back 6

vWhatdo the data mean? vWhatis the goal of the study?

Front 7

Prepare - Source of the Data

Back 7

* Isthe source objective?

* Isthe source biased?

* Bevigilant and skeptical of studies from sources that may be biased.

Front 8

Prepare - Sampling Method

Back 8

* Doesthe method chosen greatly influence the validity of the conclusion?

* Voluntaryresponse (or self-selected) samples often have bias (those with specialinterest are more likely to participate).

* Othermethods are more likely to produce good results.

Front 9

Conclude – Statistical Significance

Back 9

* Statisticalsignificance isachieved in a study when we get a result that is very unlikely to occur bychance.

Front 10

PotentialPitfalls – Misleading Conclusions

Back 10

* Concluding that one variable causes the other variable when in factthe variables are only correlated or associated together.

* Twovariables that may seemed linked, are smoking and pulse rate.

* Wecannot conclude the one causes the other. Correlationdoes not imply causality

Front 11

PotentialPitfalls - Small Samples

Back 11

Conclusions should not be based onsamples that are far too small.

Example: Basing a school suspension rate on a sample of only threestudents

Front 12

PotentialPitfalls - Loaded Questions

Back 12

If survey questions are not wordedcarefully, the results of a study can be misleading.

Front 13

PotentialPitfalls - Order of Questions

Back 13

Questions are unintentionally loaded bysuch factors as the order of the items being considered.

Front 14

PotentialPitfalls - Nonresponse

Back 14

Occurs when someone either refuses torespond to a survey question or is unavailable.

Front 15

PotentialPitfalls - Missing Data

Back 15

Can dramatically affect results.Subjects may drop out for reasonsunrelated to the study.Example- People with low incomes are less likely to report their incomes

Front 16

PotentialPitfalls - Precise Numbers

Back 16

Because as a figure is precise, manypeople incorrectly assume that it is also accurate.

Front 17

PotentialPitfalls - Percentages

Back 17

Misleadingor unclear percentages are sometimes used