PART I. Textbook problems from Freedman, Pisani & Purves:

Chapter 2. Exercise Set A: #3, #13 (pages 20 & 24), Review Exercises: #4, #10 (pages 25-27)

PART II. An Essay question from Professor Lew.

Maximum Length: One page, two if you are wordy (don't spend > hour on this OK?)

Guidance: This one is easy, but required. If you do the textbook problems above and fail to do this one, your homework assignment grade is an automatic 2/6 even if you got the above 100% correct. Be as creative or dull as you want to be. Do not get upset by the word "essay" instead, pretend you are writing an e-mail or chatting about what you have learned in the first two lectures of Statistics 10. Typing this up is optional.

Goal: To help you understand statistical concepts by having you to apply them in real-life situations.

The Question: Does sleep loss hurt the body? (see the back)

When the study (quoted in the handout) on sleep deprivation was published in 1999 in the British Medical Journal called Lancet it generated much attention. Historically, Americans are getting less sleep now than ever with our 24/7 technology-driven workplace. Currently, 61% of American adults age 18 and over indicate that they sleep less than 8 hours a night on a regular basis. (1) Please read the handout and discuss the possible problems with the study. Then (2) assume you had an infinite amount of money and time to do a proper experiment and answer the question once and for all times. How might you design a study to examine how sleep loss affects people? Keep in mind the following vocabulary when writing:

Confounding/Confounder/Confounding Effect

Treatment

Control

Placebo (this might not be possible)

Blind (this might not be possible either)

Double-Blind (this might not be possible either)

Bias

Randomization

You don't need any final conclusions (e.g. the experiment worked!), this isn't a real study. But you will need a way to measure ìhurt the bodyî ñ this could be memory loss, maybe an automobile driving simulation, maybe some medical measure. Itís up to you. Have fun with it.

Final Instructions:

WHEN YOU HAND THIS IN, STAPLE PART I and PART II TOGETHER. PUT YOUR NAME ON BOTH PARTS. THANKS FOR YOUR COOPERATION.

(source http://www.cbsnews.com/now/story/0,1597,67699-412,00.shtml)

Study: Lost Sleep Hurts The Body

* May Adversely Affect Metabolism

* Could Hasten Onset Of Age-Related Illnesses

Oct. 22, 1999

CBS (Reuters) Losing sleep can upset the body's metabolism and possibly hasten the onset of age-related illnesses like diabetes, hypertension and memory loss, researchers said Friday.

Previous studies have shown the harm to mental functioning caused by a loss of sleep, but a team of University of Chicago researchers found the body reacts adversely as well.

"We found that the metabolic and endocrine (hormonal system) changes resulting from a significant sleep debt mimic many of the hallmarks of aging," said Eve Van Cauter, who directed the study published in the Lancet, a medical journal.

"We suspect that chronic sleep loss may not only hasten the onset but could also increase the severity of age-related ailments such as diabetes, hypertension, obesity and memory loss," she said.

The sleep debt can be made up by spending longer than the normal eight hours in bed, which returns the body's chemical balance to normal, or better, the study found.

The researchers examined 11 healthy young male subjects for 16 nights. The first three nights the subjects were allowed to sleep eight hours, the next six nights they slept just four hours, and the final seven nights they spent 12 hours in bed.

After several nights racking up sleep debt, the men had heightened levels of blood glucose and their ability to secrete insulin and respond to insulin decreased by 30 percent. Their symptoms were similar to those who suffer from diabetes.

The sleep-deprived men also had increased blood levels of cortisol -- typical in older men and thought to cause memory loss.

The results indicated young men may need more than eight hours of sleep nightly.

The researchers said the average night's sleep decreased from about nine hours early in the century to the standard eight hours today, though that number continues to shrink.