ONEWAY alcohol BY rating
/STATISTICS DESCRIPTIVES HOMOGENEITY
/PLOT MEANS
/MISSING ANALYSIS
/POSTHOC=TUKEY ALPHA(0.05).
Oneway
Notes |
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Output Created |
07-JUN-2013 12:39:57 |
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Comments |
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Input |
Data |
C:UsersdonnDocumentsGCU Lead facProject with Judy for modifying PSY845 to introduce SPSSdrinks database -revised for course applications DH.sav |
Active Dataset |
DataSet1 |
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File Label |
SPSS/PC+ |
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Filter |
<none> |
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Weight |
<none> |
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Split File |
<none> |
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N of Rows in Working Data File |
35 |
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Missing Value Handling |
Definition of Missing |
User-defined missing values are treated as missing. |
Cases Used |
Statistics for each analysis are based on cases with no missing data for any variable in the analysis. |
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Syntax |
ONEWAY alcohol BY rating /STATISTICS DESCRIPTIVES HOMOGENEITY /PLOT MEANS /MISSING ANALYSIS /POSTHOC=TUKEY ALPHA(0.05). |
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Resources |
Processor Time |
00:00:00.33 |
Elapsed Time |
00:00:00.42 |
[DataSet1] C:UsersdonnDocumentsGCU Lead facProject with Judy for modifying PSY845 to introduce SPSSdrinks database -revised for course applications DH.sav
Descriptives |
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Alcohol by Volume (in %) for brand |
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N |
Mean |
Std. Deviation |
Std. Error |
95% Confidence Interval for Mean |
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Lower Bound |
Upper Bound |
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VeryGood |
11 |
4.9000 |
.17889 |
.05394 |
4.7798 |
5.0202 |
Good |
14 |
4.6000 |
.38829 |
.10377 |
4.3758 |
4.8242 |
Fair |
10 |
4.5100 |
.34140 |
.10796 |
4.2658 |
4.7542 |
Total |
35 |
4.6686 |
.35295 |
.05966 |
4.5473 |
4.7898 |
Descriptives |
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Alcohol by Volume (in %) for brand |
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Minimum |
Maximum |
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VeryGood |
4.70 |
5.20 |
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Good |
4.00 |
5.50 |
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Fair |
3.90 |
5.00 |
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Total |
3.90 |
5.50 |
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Test of Homogeneity of Variances |
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Alcohol by Volume (in %) for brand |
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Levene Statistic |
df1 |
df2 |
Sig. |
1.420 |
2 |
32 |
.256 |
ANOVA |
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Alcohol by Volume (in %) for brand |
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Sum of Squares |
df |
Mean Square |
F |
Sig. |
Between Groups |
.906 |
2 |
.453 |
4.357 |
.021 |
Within Groups |
3.329 |
32 |
.104 |
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Total |
4.235 |
34 |
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Post Hoc Tests
Multiple Comparisons |
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Dependent Variable: Alcohol by Volume (in %) for brand |
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Tukey HSD |
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(I) Rated Quality of Brand |
(J) Rated Quality of Brand |
Mean Difference (I-J) |
Std. Error |
Sig. |
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VeryGood |
Good |
.30000 |
.12995 |
.069 |
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Fair |
.39000* |
.14093 |
.025 |
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Good |
VeryGood |
-.30000 |
.12995 |
.069 |
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Fair |
.09000 |
.13354 |
.780 |
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Fair |
VeryGood |
-.39000* |
.14093 |
.025 |
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Good |
-.09000 |
.13354 |
.780 |
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Multiple Comparisons |
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Dependent Variable: Alcohol by Volume (in %) for brand |
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Tukey HSD |
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(I) Rated Quality of Brand |
(J) Rated Quality of Brand |
95% Confidence Interval |
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Lower Bound |
Upper Bound |
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VeryGood |
Good |
-.0193 |
.6193 |
Fair |
.0437* |
.7363 |
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Good |
VeryGood |
-.6193 |
.0193 |
Fair |
-.2382 |
.4182 |
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Fair |
VeryGood |
-.7363* |
-.0437 |
Good |
-.4182 |
.2382 |
*. The mean difference is significant at the 0.05 level. |
Homogeneous Subsets
Alcohol by Volume (in %) for brand |
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Tukey HSDa,b |
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Rated Quality of Brand |
N |
Subset for alpha = 0.05 |
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1 |
2 |
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Fair |
10 |
4.5100 |
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Good |
14 |
4.6000 |
4.6000 |
VeryGood |
11 |
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4.9000 |
Sig. |
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.784 |
.082 |
Means for groups in homogeneous subsets are displayed. |
a. Uses Harmonic Mean Sample Size = 11.436. |
b. The group sizes are unequal. The harmonic mean of the group sizes is used. Type I error levels are not guaranteed. |
Means Plots
Directions:
Review the SPSS output file which reports the results of the between-group (independent group) one-way ANOVA to see if the mean alcohol by volume (%) of the beer differs as a function of quality of the brand as rated by a beer expert (in 2012). Answer the following questions based on your observations of the SPSS output file:
- Looking at the descriptives (first information), do you see differences in the mean alcohol contents for the three levels of quality? Explain.
- Looking at the Test for Homogeneity of Variances (Levene Statistic), is it reasonable to proceed with the ANOVA? Is the assumption met, or violated? How do you know?
- Looking at the results of the ANOVA, is there a significant difference in the mean alcohol content for beers in the three quality groups? How do you know? Write the results in the following format: F(df value) = ___, p value = ______.
- The pairwise post hoc tests indicate which quality groups’ means are statistically significantly different for the others. Using the results of the Tukey HSD post hoc test, what two quality rating groups had significantly different mean alcohol by volume levels? How do you know?
Requirements
How do you get the answer and what do you understand about it?