unit 1 lesson 1
TRANSCRIPT
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
Unit 1: Background to Inferential Statistics
Lesson 1: Levels of Scale
EDER 6010: Statistics for Educational Research
Dr. J. Kyle Roberts
University of North Texas
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
What is Statistics?
•Making sense of data
Used with permission: www.jasonlove.com
•Synthesizing
•Inference
•STATISTICS IS NOT MATH!!!!
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
Levels of Scale
Nominal
Ordinal
Interval
Ratio
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
Nominal Scaling
•In nominal scaling, each of the values has a meaning.
•Each observation belongs to one mutually exclusive category and has no logical order.
•Examples:
Gender Ethnicity ProfessionGroup
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
Ordinal Scaling
•In ordinal scaling, each of the values is in rank order.
•Each observation belongs to one mutually exclusive category, but we now have logical order.
•Examples:
Likert-type scalesLetter Grades
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
Interval Scaling•In interval scaling, each of the values has a specific order that reflects equal differences.
•Each observation belongs to one mutually exclusive category, with logical order, and equal differences between each of the points.•Examples:
Temperature IQ Scores SAT/GRE Scores
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
Ratio Scaling•In ratio scaling, each of the values has a specific order that reflects equal differences and a “true” zero.
•Each observation belongs to one mutually exclusive category, with logical order, equal differences between each of the points, and has a “true” zero.•Examples:
Kelvin Scale Height/Weight Speed
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
Why so many levels?
Only interval and ratio scales can be submitted to math operations
Average gender???
Average ethnicity???
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
A few practice questions
• Nominal
• Ordinal
• Interval
• Ratio
Which level of scale is implied by the following statement: “Jill’s score is three times greater than Eric’s score.”
• Nominal
• Ordinal
• Interval
• Ratio
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
A few practice questions
• Nominal
• Ordinal
• Interval
• Ratio
Which level of scale is implied by the following statement: “Addie had the highest score.”
• Nominal
• Ordinal
• Interval
• Ratio
Next Slide
Copyright 2004Dr. J. Kyle Roberts
University of North Texas
Unit 1: Background to Inferential Statistics
Lesson 1: Levels of Scale
EDER 6010: Statistics for Educational Research
Dr. J. Kyle Roberts
University of North Texas