ANOVA

Problem Set #4 – ANOVA

Sleep researchers have theorized that, in a broad evolutionary sense, sleeping disruptions during periods of perceived environmental threat may have survival value. Previous research had shown that individuals experiencing anxiety or stress exhibit reduced periods of deep sleep and increased periods of light sleep because a person can most easily be aroused by a sound in the environment while in light sleep (Kilpatrick & Feeney, 2003). An attachment researcher conducted a study to examine the effects of anxious, avoidant and secure attachment styles on the physiology of sleep in children. The investigator hypothesized that children with anxious (and perhaps avoidant) attachment styles experience more sleep disturbances than children with secure attachment styles because they feel responsible for monitoring the external environment and regulating the distance between themselves and their parents. These children may find it difficult to sleep when their parents are physically absent and may develop patterns of light sleep because of the need to be aware of their parents’ presence at all times. Deep sleep can be experienced as threatening to attachment bond and thus dangerous to the child. The sleep patterns of 10 secure, 10 anxious and 10 avoidant 5-year-old children were monitored. Of primary importance to the attachment researcher was the overall percentage of time that each child spent in deep (delta) sleep. It was hypothesized that children who are insecurely attached to their primary caregivers will spend a lower percentage of time in deep (delta) sleep as compared to their secure counterparts. Below is the average amount of time that each child spent in delta sleep, expressed as a percentage of total sleep time.

1. What should the null hypothesis of your investigation be? What is your alpha level? 2.Within or Between groups? One-way or two-way ANOVA? Why?3. What are the mean scores, SD, and SE of the three groups? 4.Represent the comparison of means in a bar chart with standard error, labels for the mean, and title. 5.Was Levene’s test significant?Which post-hoc test should you use?6. What is the between groups variance (mean square)? Within groups?fvalue (APA format)? F value significance?7. What is thepost-hoc significance of each comparison? 8. Should you accept or reject the null hypothesis? 9. What are your final conclusions about attachment style and sleep in children? (which children sleep better?)

On Your Own –The same researchers are curious as to whether attachment style of children has an effect on deep sleep of their parent. The sleep patterns of 15 parentswith secure children, 15parents withanxious children, and 15parents withavoidant children were monitored.It was hypothesized that attachment style of a child would have an effect on parent deep sleep, and there would be a difference between groups. Below are the data for percentage of time parents were in delta sleep.

1. What should the null hypothesis of your investigation be? What is your alpha level? 2. Within or Between groups? One-way or two-way ANOVA? Why? 3. What are the mean scores, SD, and SE of the three groups? 4. Represent the comparison of means in a bar chart with standard error, labels for the mean, and title. 5. Was Levene’s test significant?Which post-hoc test should you use? 6. What is the between groups variance (mean square)? Within groups? f value (APA format)? f value significance? 7. What is the post-hoc significance of each comparison? 8. Should you accept or reject the null hypothesis? 9. What are your final conclusions about child attachment style and sleep in parents? (which parents sleep better?)

*Dis