Question

Research Scenario: A researcher is attempting to determine the effects of sex and sleep deprivation on a reaction time task. Participants (5 men; 5 women) in an experiment are given a computerized search task. They search a computer screen of various characters and attempt to find a particular character on each trial. When they find the designated character, they press a button to stop a timer. Their reaction time (in ms) on each trial is recorded (note, so the lower the number, the faster the time). Male and female subjects participated in the study across three days, and completed the task after having 0, 4, or 8 hours of sleep. The reaction time data for the 10 subjects appear below. Using this table, enter the data into a new SPSS data file and run the appropriate test to assess whether sleep deprivation and/or sex affect performance on reaction time. Remember that between subjects variables such as “Sex” will be represented using a single column in SPSS. Within subjects variables such as sleep would be represented in multiple columns – one per level. Hint: for this data entry, you will end up for a total of four columns in SPSS.

Write an APA-style Results section based on your analysis

	Men	Women
0 hours	12	11
	13	12
	12	13
	11	12
	11	11
4 hours	10	8
	10	8
	10	10
	8	10
	7	9
8 hours	7	5
	5	6
	7	8
	6	6
	7	8

Answer 1

Solution:

Here, we have to use two way analysis of variance or two way ANOVA F test for checking the given hypothesis. The null and alternative hypotheses for this test are given as below:

Null hypothesis: H₀: There is no significant effect of sleep deprivation, sex, or their interaction on the performance of reaction time.

Alternative hypothesis: H_a: there is a significant effect of sleep deprivation, sex, or their interaction on the performance of reaction time.

Here, we assume level of significance = α = 0.05

The two way ANOVA table by using SPSS is given as below:

Between-Subjects Factors
		Value Label	N
Sex	.00	Male	15
	1.00	Female	15
Sleep Deprivation	1.00	0 hours	10
	2.00	4 hours	10
	3.00	8 hours	10

Tests of Between-Subjects Effects
Dependent Variable:Reaction Time
Source	Type III Sum of Squares	df	Mean Square	F	Sig.
Corrected Model	140.700a	5	28.140	24.120	.000
Intercept	2484.300	1	2484.300	2129.400	.000
Sex	.033	1	.033	.029	.867
Sleep	140.600	2	70.300	60.257	.000
Sex * Sleep	.067	2	.033	.029	.972
Error	28.000	24	1.167
Total	2653.000	30
Corrected Total	168.700	29
a. R Squared = .834 (Adjusted R Squared = .799)

From this table, it is observed that the p-value for the variable sex is given as 0.867. This p-value is greater than alpha value 0.05, so there is insufficient evidence to conclude that the variable sex has statistically significant effect on the performance of reaction time.

The p-value for the variable sleep is given as 0.00 which is less than alpha value 0.05, so there is sufficient evidence to conclude that the variable sleep deprivation has statistically significant effect on the performance of reaction time.

The p-value for the interaction between the given two variables sex and sleep deprivation is given as 0.972 which is greater than alpha value 0.05. So, there is insufficient evidence to conclude that there is a statistically significant effect of interaction of sex and sleep deprivation on the performance of reaction time.