EC255 Chapter Notes - Chapter 1: Variance, Level Of Measurement, Standard Deviation
Chapter 1 – Introduction
1.2 Basic Statistical Concepts
- Statistics: science dealing w collection, analysis, interpretation + presentation of numerical data
-
- Population: collection of persons, objects or items of interest
- Census: the data from the whole population for a given measurement of interest
- Sample: portion of the whole – representative of the whole
- 2 branches of stats:
1. Descriptive stats: using data gathered on a group to describe or reach conclusions about the group
➢ Includes most athletic stats – used to describe an individual or team effort
➢ Statistical data by businesses
➢ Transform data into information
2. Inferential stats: data gathered from a sample and used the stats generated to reach conclusions about the
population from which the sample was taken
➢ Used to infer something about a larger group
➢ Also called inductive stats
➢ I.e. pharmaceutical research / advertising on market segments
➢ Advantage: enable researcher to study wide range of phenomena w/o conducting a census
➢ Transform information into knowledge
- Parameter: descriptive measure of population
- Examples of Parameters:
o Population mean – μ
o Population Variance – σ2
o Population standard deviation – σ
- Statistic: descriptive measure of a sample
- Examples of Statistics:
o Sample mean –
o Sample variance –
o Sample standard deviation –
1.3 Variables and Data
- Variable: characteristic of any entity being studied that is capable of taking on different values
o Produce a measurement that can be used for analysis
- Measurement: when a standard process is used to assign number to particular attributes/characteristics of a variable
o after recorded and stored, denoted as data
- Data: recorded measurements
1.4 Data Measurement
- Researcher needs to know the level of data measurement represented by
the numbers being analyzed
- Levels of Data Measurement:
1. Nominal
2. Ordinal
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Document Summary
Statistics: science dealing w collection, analysis, interpretation + presentation of numerical data. Population: collection of persons, objects or items of interest. Census: the data from the whole population for a given measurement of interest. Sample: portion of the whole representative of the whole. 2 branches of stats: descriptive stats: using data gathered on a group to describe or reach conclusions about the group. Includes most athletic stats used to describe an individual or team effort. Inferential stats: data gathered from a sample and used the stats generated to reach conclusions about the population from which the sample was taken. Used to infer something about a larger group. Advantage: enable researcher to study wide range of phenomena w/o conducting a census. I. e. pharmaceutical research / advertising on market segments. Examples of parameters: population mean , population variance 2, population standard deviation .
