STATISTICS Statistics refers to a set of techniques that are used to transform raw data into useful information

Three Terms Describe Statistics: Descriptive Statistics or Data Description; Probability; and Inference

Descriptive Statistics: Involves computing summary measures and constructing graphs, tables and charts to illustrate those measures

Probability: Involves the measurement of the uncertainty that the decision maker feels about the occurrence of some outcome

Inference: Involves drawing conclusions about a large body of data when only a small portion of those data has actually been observed

Statistical Decision-Making Process: Decision Problem Statistical Plan Data Description and Summary Analysis and Conclusions Testing Validity of Results If Yes, Solution to Decision Problem If No, Revise the Statistical Plan

A Statistical Plan Includes: Identification of a Data Base; Techniques for Describing the Data; A Means of Analyzing the Data; and Measures of Validity (Error) in Working with the Data

Data Base: Primary Data: Data collected by observation, experiment, simulation or from surveys Secondary Data: Data published by governmental, industrial or individual sources

Methods of Obtaining Data: Observation; Personal Interview; Telephone Interview; and Mail Questionnaires

Data Levels: Nominal, where numbers or symbols are used to describe an item or characteristic; Ordinal, where decision makers rank-order the observations; Interval, where the measurement of the distance between two data items is allowed; Ratio, where the data have a unique or zero point