1. Business 205

2. Review of Previous Class Milestone #1 Groups Math Review Symbolic Manipulation Excel Review

3. Preview for Today Sampling NOIR Validity Reliability Work on Milestone #1

4. Statistics Descriptive Statistics A way to present quantitative descriptions in a manageable (aka: numerical) way Example: 52% Females, 48% Males Inferential Statistics Makes statements about a population; predicting unknown values

5. Types of Data Quantitative Numbers, scales Qualitative Groups or categories

6. Levels of Measurement What is “measurement”? Who cares? Is it important?

7. “NOIR” the French word for Black AKA: Levels of Measurement Nominal Ordinal Interval Ratio

8. N is for Nominal Distinguish categories that comprise a given variable All you can say about it is that it is or isn’t! EXAMPLE: Male/Female CODING FOR NOMINALS: 0/1

9. O is for Ordinal Reflect a rank order among categories comprising a variable All you can say is how they are ranked NOT how much better they did or were liked. EXAMPLE: 1 st, 2 nd, 3 rd

10. I is for Interval Distances between numbers have a real meaning You can now claim there is equal distance between numbers. You CANNOT say one is twice as better as another. This has no real zero. EXAMPLE: 80 F and 90 F == 50 F and 60 F

11. R is for Ratio Distances between numbers have a real meaning You can claim there s equal distance between numbers AND you can say one is twice as much as another. This has a real zero. EXAMPLE: Andy is 20, his sister is 10

12. Reliability Whether a particular technique, applied repeatedly to the same object, would yield the same result each time. Reliability = X true X observed Example: You use a scale to measure the weight of an apple 15 times. You find out that it is 1 lb each time. Alpha =.70  =.70

13. Reliability: How to read it… Alpha =.70  =.70 What this means: We are 70% sure (confident) that what we found is true. Also known as a “confidence interval”

14. Reliability: Try it  =.80  =.10  =1.00 What do each of the  levels mean? Which is better? Which is the worst? Is there an acceptable “cut off”?

15. Validity Extent to which an empirical measure adequately reflects the real meaning of the concept under consideration Example: You use a scale that was balanced to zero for all measurements.

16. Valid and Reliable? Can a scale be valid? Can a scale be reliable? Can a scale be valid and reliable? What about the EPA results?

17. Process Actions and/or operations that transform inputs to outputs. Input Black Box (process) Output

18. Variables Independent Variable (IV) A variable thought to produce change in another variable Input Dependent Variable (DV) A variable thought to be changed by another variable Output

19. Milestone #1 Groups of 5 or 6 Write out a team contract Pick what business topic you want to work on Type it up All group members must sign it!