School

University of GuelphDepartment

Sociology and AnthropologyCourse Code

SOAN 2120Professor

Scott SchauThis

**preview**shows half of the first page. to view the full**2 pages of the document.**SOAN 2120 MARCH 23, 2012

Measure of Dispersion

Range: distance separating the highest and lowest observation recorded

Standard deviation: average dispersion of all values from the mean

Percentiles: division of the sample into various groups of equal size where the

observed values fall

- Inter-quartile range: difference between the 75th and 25th percentile

The Range

- Highest number – the lowest number = the range

- Interpretation: The difference between the student who ate the most Kraft

dinners and the student who had the least is 45

Noir and the MCT (measures of central tendency)

Nominal -> yes mode ->no median -> no mean -> no measure of dispersion

Ordinal -> yes -> yes -> no -> no

Interval -> yes -> yes -> yes -> yes

Ratio -> yes -> yes -> yes -> yes

Nominal and ordinal = categorical

Interval and ratio = numerical

BIVARIATE STATISTICAL ANALYSIS

Sub-Group Comparisons

- Statistical descriptions of some variable are broken into subsets of a

population for the sake of comparison

- Description and explanatory

- Comparisons are often based on the assumption of causality

- One variable causes the other

CONTINGENCY TABLES

- 2 variables being compared

Constructing a table for Bivariate Analysis

- AKA contingency tables

- Values of the D.V> are contingent on values of the I.V.

1. Observations are divided into groups according to their attributes of the I.V.

2. Each of these subgroups is then described in terms of the D.V.

3. Table is the ‘percentage’ according to the I.V.

4. Table is read by comparing the I.V. Subgroup with one another in terms of

the same category of the D.V.

MEASURES OF DISPERSION/VARIABILITY

- the variance (o with line(sigma) 2, s2 ) and standard deviation (sigma, s)

- Interpretation of the Standard Deviation

- Indirect indicators of differences

- It is a single number that represents the spread or amount of dispersion in a

set of data

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