Statistics : The science of learning from data Chapters 1-4: Tools and strategies for organizing, describing, analyzing data Chapter 5 : How to produce data Chapter 6-9: Probability: The study of chance behavior Chapter 10-15 : Testing Claims/Computing estimates. Preliminary Chapter.
2. How many variables? Defs of these variables? What units? (lbs? kilos?)
3. Reasons the data was gathered? (For a sample or population)?
Every set of data comes with background information to help us understand the data!Ask the following questions
Where can we find good data?
www.nces.ed.gov (Nat’nl Center for Education Statistics website)
www.fedstats.gov (good source for projects)
Statistical offices of foreign countries (www.statcan.ca, www.inegi.gob.mx )
In 1976, Shere Hite published The Hite Report on Female Sexuality, Seven Stories Press, Ny, Ny 2004. The conclusions reported in her book were based on 3,000 returned surveys from 100,000 surveys distributed by women’s groups. The results were that women were highly critical of men. In what way might the author’s findings have been biased?
1) Examine the variables
2) Graph them.
Distribution of a Variable: what values the variable takes on and how often it takes these values.
The pattern of a variable is its distribution.More Defs!
Number of goals scored by the US women’s soccer team in 34 games played in the 2004 season are:
3 0 2 7 8 2 4 3 5 1 1 4 5 3 1 1 3 3 3 2 1 2 2 2 4 3 5 6 1 5 5 1 1 5
What does this tell us about the performance of the US women’s team in 2004?
Air travelers would like their flights to arrive on time. Airlines collect data about on-time arrivals and report them to the department of Transportation. Here’s one month’s data for flights from several western cities for two airlines:
An association or comparison that holds for all of several groups can reverse direction when the data are combined to form a single group.
25%? 10% 1%? 0.01?
Our willingness to declare an event “unlikely” is usually based on….
Communication in Statistics: IMPORTANT