Question

Problem Set 4.8: One-Way ANOVA in SPSS

• Criterion: Calculate an ANOVA in SPSS.
• Data: Tyrone is testing out dye strength after washing dyed fabric for his new fabric line. He dyes his fabrics blue, green, and yellow and washes the fabric one time. The following are the dye strength results for 10 pieces of fabric in each color after one wash:

Blue	Green	Yellow
98	55	66
96	53	71
92	57	73
92	60	71
88	52	76
86	54	72
89	62	74
92	53	69
94	54	68
90	65	70

• Instruction: Complete the following steps:

1. Open SPSS and create a New DataSet.
2. Click the Variable View tab and enter Color and DyeStrength as the variables. Click the Values box for the Color row and define 1 as blue, 2 as green, and 3 as yellow.
3. Enter the data.
4. In the Toolbar, click Analyze, select Compare Means, and then select One-Way ANOVA.
5. Click DyeStrength and then click Arrow to send it over to the Dependent List box.
6. Click Color and then click Arrow to send it over to the Factor box.
7. Click OK and copy and paste the output below.

Problem Set 4.9: One-Way ANOVA results in APA style

• Criterion: Report ANOVA results in APA format.
• Data: Use the Dye Strength data from Problem Set 4.8.
• Instruction: Complete the following:

a.   State the null hypothesis.

b.   Report your results in APA format (as you might see them reported in a journal article).

Answer 1

Result:

Data: Tyrone is testing out dye strength after washing dyed fabric for his new fabric line. He dyes his fabrics blue, green, and yellow and washes the fabric one time. The following are the dye strength results for 10 pieces of fabric in each color after one wash:

State the null hypothesis.

Ho: µ₁= µ₂= µ₃

Ho: There is no difference in mean dye strength among the three color conditions.

H1: At least one of the mean is different from the others

SPSS output:

Descriptives
DyeStrength
	N	Mean	Std. Deviation	Std. Error	95% Confidence Interval for Mean		Minimum	Maximum
					Lower Bound	Upper Bound
Blue	10	91.7000	3.65300	1.15518	89.0868	94.3132	86.00	98.00
Green	10	56.5000	4.40328	1.39244	53.3501	59.6499	52.00	65.00
Yellow	10	71.0000	2.94392	0.93095	68.8940	73.1060	66.00	76.00
Total	30	73.0667	15.12234	2.76095	67.4199	78.7134	52.00	98.00

ANOVA
DyeStrength
	Sum of Squares	df	Mean Square	F	Sig.
Between Groups	6259.267	2	3129.633	226.785	0.000
Within Groups	372.600	27	13.800
Total	6631.867	29

Report your results in APA format (as you might see them reported in a journal article).

A one-way between subjects ANOVA was conducted to compare the effect of color on dye strength. There was a significant effect of color on Dye strength at the p<.05 level for the three color conditions [F(2, 27) = 226.79, p <.001].