2 The Five W’s Where- *Who-are the cases *What-are the variables ( gives information about each of the cases)*Why-helps us to decide which way to treat the variableWhen-Where-*hoW- can make the difference between insight and nonsense
3 Classification of Variables Categorical variables- indentify a category for each case. ( usually think about counts of cases that fall into each category) or a variable that names categories can by with numerals or wordsQuantitative variables- record measurements or amounts of something. Must have units or a variable in which the numbers act as numerical values
4 VocabularyContext-The context ideally tells Who was measured, What was measured , How the data were collected, and the when and the why the study was performed.Data-Systematically recorded information, whether number or labels, together with its context.
5 Vocabulary ContinuedData Table- An arrangement of data in which each row represents a case and each column represents a variable.Case- is an individual about whom or which we have data.Population- all cases we wish we knew aboutSample-the cases we actually examine in seeking to understand the much larger population
6 Vocabulary ContinuedVariable- hold the information about the same characteristic for many cases.Units- a quantity or amount adopted as a standard measurement, such as dollars, hours or grams
7 Our data collectionWhat are some of the things you learned about the class by inspecting our data?
8 Our data Student Gender Length height # letters states siblings politicalpennystat1F31.25710MA420.2511170.512LK81451521916C130.750.12525180.65196
9 Example 2Consider the numbers 17, 21, 44, 76. Are those data?
10 Example 2 con’t17, 21, 44, 76Context is critical- they could be test score, ages in a golf foursome, or uniform numbers of the starting backfield on the football team.Our reaction changes
11 Example 3 What are the five W’s of the following data A consumer repots article on energy bars gave the name brand, flavor, price, number of calories, and grams of protein and fat.Who:What:When:Where:How :Why:
12 Example 3 con’tCategorical Variables:Quantitative Variables:
13 Example 4A report on the Boston Marathon listed the runner’s gender, country, age, and time.Who:What:When:Where:How :Why:
14 Example 5 Con’tCategorical Variables:Quantitative Variables: