Categorical vs. Quantitative Variables

1. Categorical vs. QuantitativeVariables Identifying the Difference

2. How do the items on the left side compare with the items on the right? Introduction to Statistics--Variables

3. Variables Come in 2 Varieties • Categorical (or __________) • Quantitative (or __________) Introduction to Statistics--Variables

4. Categorical Variables • Recorded usually with _______ • Records which of several __________ an individual belongs to • Count data in each ________, but you logically should not __________ it • Can calculate ___________ distributions • Includes all _________ questions • Usually—best illustrated with a ________ _____________. Introduction to Statistics--Variables

5. Quantitative Variables • Possible responses are ___________ in nature • Includes values for which it makes sense to do operations like _________ and ___________. • Includes answers to _________________ questions • Includes _______ • Illustrated with graphs like __________, ____________, ____________, & _________. Introduction to Statistics--Variables

6. FYI • Just because you have a number, doesn't necessarily make it quantitative. • For example: • ___________ • ___________ • ___________ … all _______, but it doesn't make much sense to find the or _______ _________. *These are examples of __________ applied to __________________. Introduction to Statistics--Variables

7. Overview: Qualitative vs Quantitative Data

8. Length of a pen? Type of pen? Number of pens in box? Maker of pen? Flow of ink in ml/sec? Color of pen’s ink? Point size of pen? Subject of a book? Number of pages in the book? Area of each page of book? Number of letters on a page? Number of weeks on best seller list? Categorical or Quantitative? Introduction to Statistics--Variables

9. Style of pants? Color of pants? Number of pairs of pants you own? # of pockets on pants? Size of pants? Maker of the pants? Length of inseam on the pants? Categorical or Quantitative? Introduction to Statistics--Variables

10. Determine if each Variable is Categorical or Quantitative Look for Variable Names in Column Headings Variable = State = Variable = Region = Variable = Population = Variable = Males = Variable = Females = Categorical Categorical Quantitative Quantitative Quantitative Introduction to Statistics--Variables

11. Provide a Qualitative & Quantitative Description of the Image

12. Provide a Qualitative & Quantitative Description of the Image

13. Provide a Qualitative & Quantitative Description of the Image

14. Make one qualitative observation about the picture above. Explain why this is a qualitative observation. Make one quantitative observation about the picture above. Explain why this is a quantitative observation.

15. Make one qualitative observation about the picture above. Explain why this is a qualitative observation. Make one quantitative observation about the picture above. Explain why this is a quantitative observation.

16. Variables Come in 2 Varieties • Categorical (or Qualitative) • Quantitative (or Numerical) Introduction to Statistics--Variables

17. Categorical Variables • Recorded usually with words • Records which of several categories an individual belongs to • Count data in each group, but you logically should not average it • Can calculate percentage distributions • Includes all yes/no questions • Usually—best illustrated with a pie chart or bar graph. Introduction to Statistics--Variables

18. Quantitative Variables • Possible responses are numerical in nature • Includes values for which it makes sense to do operations like addingand averaging. • Includes answers to how much/how many questions • Includes units • Illustrated with graphs like stem and leaf, box plots, histograms, & scatter plots. Introduction to Statistics--Variables

19. 2 Types of Quantitative Variables • Discrete If the Q variable is a set of isolated points on the number line, we call it this. (i.e., it’s a number but it only comes in certain values) • Continuous If the Q variable forms an entire interval along the number line, we call it this. (i.e., it’s a number & it can be any value). Introduction to Statistics--Variables

20. FYI • Just because you have a number, doesn't necessarily make it quantitative. • For example: • zip codes • phone numbers • bank-accounts … all numeric, but it doesn't make much sense to find the average phone number or median zip-code. *These are examples of numbers applied to categorical data. Introduction to Statistics--Variables

21. Length of a pen? Type of pen? Number of pens in box? Maker of pen? Flow of ink in ml/sec? Color of pen’s ink? Quantitative, Continuous Categorical Quantitative, Discrete Categorical Quantitative, Continuous Categorical Categorical or QuantitativeIf Categorical, one possible category? If Quantitative, Continuous or Discrete? Introduction to Statistics--Variables

22. Subject of a book? Number of pages in the book? Area of each page of book? Number of letters on a page? Number of weeks on best seller list? Categorical or QuantitativeIf Categorical, one possible category? If Quantitative, Continuous or Discrete? Categorical Quantitative, Discrete Quantitative, Continuous Quantitative, Discrete Quantitative, Discrete Introduction to Statistics--Variables

23. Style of pants? Color of pants? Number of pairs of pants you own? # of pockets on pants? Size of pants? Maker of the pants? Length of inseam on the pants? Categorical Categorical Quantitative, Discrete Quantitative, Discrete Quantitative, Discrete Categorical Quantitative, Continuous Categorical or QuantitativeIf Categorical, one possible category? If Quantitative, Continuous or Discrete? Introduction to Statistics--Variables

24. Provide a Qualitative & Quantitative Description of the Image

25. Provide a Qualitative & Quantitative Description of the Image

26. Provide a Qualitative & Quantitative Description of the Image

27. Make one qualitative observation about the picture above. Explain why this is a qualitative observation. Make one quantitative observation about the picture above. Explain why this is a quantitative observation.

28. Make one qualitative observation about the picture above. Explain why this is a qualitative observation. Make one quantitative observation about the picture above. Explain why this is a quantitative observation.