Data Analys
ISDATA ANALYSIS USING
SPSS
Overview
• Variable
• Types of variables
Qualitative
Quantitative
• Reliability and Validity
• Hypothesis Testing
• Type I and Type II Errors
• Significance Level
• SPSS
• Data Analysis
Data Analysis Using SPSS
Dr. Nelson Michael J.
2
Variable
• A characteristic of an individual or object that can be measured
• Types:
Qualitative and Quantitative
Data Analysis Using SPSS
Dr. Nelson Michael J.
3
Types of Variables
• Qualitative variables: Variables which differ in kind rather than degree
• Measured on:
1) Nominal scale indicates categorizing into groups groups or classes.
Eg. Gender, religion, race, colour, occupation, etc
2) Ordinal scale indicates ordering of items.
Eg. Agreement – disagreement scale, customer satisfaction ratings, etc
Data Analysis Using SPSS
Dr. Nelson Michael J.
4
•
Quantitative variables: Variables which differ in degree rather than kind.
• Measured on:
1) Interval scale indicates rank and distance from an arbitrary zero measured in unit intervals.
Eg. Temperature, examination scores, etc. 2) Ratio scale indicates rank and distance from a natural zero.
Eg. Height, monthly consumption, annual budget, etc
Data Analysis Using SPSS
Dr. Nelson Michael J.
5
Reliability
• The confidence we can place on the measuring instrument to give us the same numerical value when measurement is repeated on the same object.
Eg. Instrument to measure the number of things a child can recall
Assessing reliability:
Cohen’s kappa coefficient for categorical data Cronbach’s alpha for internal reliability for a set of questions
Data Analysis Using SPSS
Dr. Nelson Michael J.
6
Validity
• To see how accurate is the relationship between the measure and the underlying trait it is trying to measure
• Eg. An instrument claimed to measure IQ may just be testing memory
• Assessing validity:
Face validity
Predictive validity
Content validity
SPSS
Overview
• Variable
• Types of variables
Qualitative
Quantitative
• Reliability and Validity
• Hypothesis Testing
• Type I and Type II Errors
• Significance Level
• SPSS
• Data Analysis
Data Analysis Using SPSS
Dr. Nelson Michael J.
2
Variable
• A characteristic of an individual or object that can be measured
• Types:
Qualitative and Quantitative
Data Analysis Using SPSS
Dr. Nelson Michael J.
3
Types of Variables
• Qualitative variables: Variables which differ in kind rather than degree
• Measured on:
1) Nominal scale indicates categorizing into groups groups or classes.
Eg. Gender, religion, race, colour, occupation, etc
2) Ordinal scale indicates ordering of items.
Eg. Agreement – disagreement scale, customer satisfaction ratings, etc
Data Analysis Using SPSS
Dr. Nelson Michael J.
4
•
Quantitative variables: Variables which differ in degree rather than kind.
• Measured on:
1) Interval scale indicates rank and distance from an arbitrary zero measured in unit intervals.
Eg. Temperature, examination scores, etc. 2) Ratio scale indicates rank and distance from a natural zero.
Eg. Height, monthly consumption, annual budget, etc
Data Analysis Using SPSS
Dr. Nelson Michael J.
5
Reliability
• The confidence we can place on the measuring instrument to give us the same numerical value when measurement is repeated on the same object.
Eg. Instrument to measure the number of things a child can recall
Assessing reliability:
Cohen’s kappa coefficient for categorical data Cronbach’s alpha for internal reliability for a set of questions
Data Analysis Using SPSS
Dr. Nelson Michael J.
6
Validity
• To see how accurate is the relationship between the measure and the underlying trait it is trying to measure
• Eg. An instrument claimed to measure IQ may just be testing memory
• Assessing validity:
Face validity
Predictive validity
Content validity