Quantitative Methods- Study Guide- Types of Skewness
Types of skewness
Positive or right
Mean is above the median
Graphically to the right
Negative or left
Mean is below the median
Graphically to the left
Median is resistant to skewness
Median versus Mean
Quantitative Methods- Study Guide- Tabular and Graphical Presentation
Part II
Tabular and Graphical Presentation
Review
Measures of central tendency
Measures of variation about the typical value
Frequency of the mode
Variance/standard deviation
Skewness
E
Quantitative Methods- Study Guide- Deviation and Variance
Deviation
How far away from the mean is each observation?
Sum of deviations: add up all the differences between each value and the
mean
(xi x)
Variance
The Variance is the sum of squared deviati
Quantitative Methods- Study Guide- Central Tendency
Central Tendency
Compute the mode, median, and mean for each of these variables:
Compare your answers to those of other members of the class.
Central Tendency
Data set #1
Mode = 5
Median = 5
Mean = 5
Cl
Quantitative Methods- Study Guide- Ordinal Data Examples
Ordinal Data
Bar Charts: two notes
As with nominal data, bars do not touch (not a histogram)
Unlike nominal data, order of categories matters
Least (left) to most (right) on the x-axis
Ordinal Data
Quantitative Methods- Study Guide- R Exercise
R Exercise
Pollock, Companion pp. 33-34
Data from General Social Survey 2008
R Exercise
Pundit 1: Our society has a sizeable minority of traditionally minded
individuals who think that the proper place for
Quantitative Methods- Study Guide- Measuring Description and Examples
STEP TWO: Describe how it is measured Operational Definition
Literally, what operations do we perform to create a variable that measures
the concept.
E.g. How were the operations diffe
Quantitative Methods- Study Guide- Quantitative Research
To do Quantitative Research we must operationalize concepts
Define a concept
Describe how it is measured
Take measurements, create a variable
If we do this well, we get good data. Badly not so good
Quantitative Methods- Study Guide- Definition and Measurement Basics
Definition and Measurement of Concepts
Review
Key course requirements
Select final exam versus final paper option Measurement and descriptive
statistics
First part of class.
Inferential
Quantitative Methods- Study Guide- Outline for Concepts
Outline
What are Concepts?
Clarify and define concepts
Operationalizing concepts as variables
Validity and reliability
Variables versus concepts
Levels of measurement
Levels of analysis
Concepts are
Quantitative Methods- Study Guide- Dispersion
Dispersion
What we need is some way to differentiate between data set #1 and
data set #2 to measure the degree of heterogeneity versus homogeneity.
Measures of dispersion indicate how the other values vary aro