Descriptive and Inferential Statistics in SPSS
Ordinal Scale: Size of hometown or city
ANALYZEDESCRIPTIVE STATISTICSFREQUENCIES
Size of home town or city
Frequency
Percent
Valid Percent
Cumulative
Percent
Under 10,000
10,00 to 99,999
100,000 to 499,999
5

Paired Samples t-Test and ANOVA in SPSS
Example: AA Concepts Survey
Are there differences in preferences for Economy 4 seat hybrid and Standard 4 seat hybrid
models?
SPSS Directions:
i.
ANALYZECOMPARE MEANSPAIRED SAMPLES t-TEST.
ii.
Select Preference: Eco

Hypothesis Testing: Non-Directional Hypothesis
I.
For categorical data (or proportions for nominal or ordinal scales):
Write non-directional null (Ho) and alternative (Ha) hypotheses:
Ho: = Hstatistically, the population proportion, , and H are the same.

Differential Analysis:
I.
Formula for significance of the difference between two proportions/percentages
(nominal & ordinal scales):
1. Write the null and alternative hypotheses.
Ho: p1 = p2statistically, the two percentages are not significantly differen

ANOVA in SPSS
If sig value is less than or equal to 0.05, we reject the null and conclude that at least two group means are
different. The Duncans post-hoc test reveals the differences.
1. People in the age group of 19-24 years have the highest mean prefe

Descriptive Analysis:
MODE & MEDIAN Categorical datanominal or ordinal scales
SPSS command sequence:
ANALYZEDESCRIPTIVE STATISTICSFREQUENCIES
Select variable(s)/questions(s)
Click OK
Points to think about:
1. How does the frequency distribution expla

Sample t-Test in SPSS
p is highlighted. Sp was previously calculated as 1.4 (please see page 5). Z-calculated = (26.7
25)/1.4 = 1.214286 or 1.214.
Since -1.96 1.214 +1.96, we fail to reject the null hypothesis.
For Metric data (interval and ratio scales)

One-Sample Test in SPSS
Note:
(i)The default confidene level in SPSS is 95%. This can be changed to the desired level by
clicking on options in the One-Sample Test window and typing in the desired level (e.g., 99%).
(ii) For large sample, t-test and z-tes

Inferencial Analysis in SPSS
Example from AAConcepts data:
We are 95% confident that the true % of the population that lives in a city of 1 million and
more population falls between 24.0% and 29.4%.
1. Compute frequency table for Size or town or city.
SPS

Computing Confidence Intervals in SPSS
1. Compute using: z = (p - ) / sp
I.
For metric data (interval and ratio scales):
1. Computing Confidence Intervals:
ANALYZECOMPARE MEANSONE-SAMPLE t-TEST with test value 0.
Step 1: Click ANALYZE.
Step 2: Move mouse