1. Basics of Statistics

2. Statistics
the science of collecting, analyzing, and drawing conclusions from data

3. Descriptive statistics
the methods of organizing & summarizing data

4. Inferential statistics
involves making generalizations from a sample to a population
This will be the 2nd semester

5. Population
The entire collection of individuals or objects about which information is desired

6. Sample
A subset of the population, selected for study in some prescribed manner

7. Data
observations on single variable or simultaneously on two or more variables

8. Context (the W’s) Tells us WHO was measured WHAT was measured
WHEN the study was performed
WHERE the data was collected
WHY the study was performed
HOW the data were collected

9. Variable
any characteristic whose value may change from one individual to another

10. Types of variables

11. Types of Variables
Variables can be classified as categorical (aka, qualitative) or quantitative (aka, numerical).  

12. Categorical variables
Categorical variables take on values that are names or labels.
or qualitative
identifies basic differentiating characteristics of the population

13. Is it or isn’t it? Determine whether a variable is categorical or not.
Favorite Color
Height
Zip Code
Number of tweets
Shoe Size
Breed of dog
Categorical
Not
Categorical
Not
Not
Categorical

14. Card Sort
Do the Card Sort Activity with your partner. Once completed, check your answers with your group.
Prepare to discuss results.

15. Card Sort Answers Categorical Variables: Brand of toothpaste
College Major
Telephone Company
Checking Account Location
School Attended
Customer Service Survey
School Mascot

16. Quantitative variables
or numerical
observations or measurements take on numerical values
have units (dollars, hours, etc)
two types - discrete & continuous

17. Discrete (numerical)
listable set of values
usually counts of items

18. Continuous (numerical)
data can take on any values in the domain of the variable
usually measurements of something

19. Classification by the number of variables
Univariate - data that describes a single characteristic of the population
Bivariate - data that describes two characteristics of the population
Multivariate - data that describes more than two characteristics (beyond the scope of this course

20. Identify the following:
gender
age
Right or left handed
How you got to school
Number of movies
number of girls in class
Fastest speed driven
categorical
numerical

21. Types of Distributions
4 common types

22. Symmetrical
refers to data in which both sides are (more or less) the same when the graph is folded vertically down the middle
bell-shaped is a special type
has a center mound with two sloping tails

23. Uniform
refers to data in which every class has equal or approximately equal frequency

24. Skewed (left or right)
refers to data in which one side (tail) is longer than the other side
the direction of skewness is on the side of the longer tail

25. Bimodal (multi-modal)
refers to data in which two (or more) classes have the largest frequency & are separated by at least one other class