PH 150A Introduction to Epidemiology and Human Disease
UNIVERSITY OF CALIFORNIA, BERKELEY SCHOOL OF PUBLIC HEALTH
LAB F: Sampling, Summarizing Data and Introduction to Statistics
Due: Week of March 17-21
For this assignment, download and read the following study design articles from the
Type your answers.
Al-Delaimy WK, Manson JE, Willett WC, Stampfer MJ, Hu FB. Snoring as a risk factor
for type II diabetes mellitus: a prospective study. Am J Epidemiol. 2002;155:387-393.
Turabelidze G, Lin M, Wolkoff B, Dodson D, Gladbach S, Zhu BP. Personal hygiene and
infection. Emerg Infect Dis. 2006;12:422-
Rose A, Roy S, Abraham V, et al. Solar disinfection of water for diarrhoeal
prevention in southern India. Arch Dis Child. 2006;91:139-141.
Part I: General questions on the lectures
1. What is statistical inference?
The development of a generalization based on sample data.
2. What is the purpose of performing statistical tests?
To test whether the observed associations are caused by chance alone.
It refers to the alpha,
which is the probability that you would observe the finding or greater if the null hypothesis (i.e.,
no association) were true.
3. The following are CD4+ counts of 10 people in a study on HIV:
230, 260, 415, 319, 415, 415, 252, 420, 500, 516
Calculate the following values:
(230+ 260+ 415+ 319+ 415+ 415+ 252+ 420+ 500+ 516)/10=374.2
4. Define statistical power.
Probability of concluding a difference exists when it does.