1. Data Classification
Qualitative Data: attributes, labels, or non numerical entries. This is also called Categorical Data.
Quantitative Data: numerical measurements or counts
City
Population
Baltimore, MD
702,979
Boston, MA
547,725
Dallas, TX
1,022,830
Las Vegas, NV
327,878
Lincoln, NE
203,076
Seattle, WA
520,947
Quantitative Data
Qualitative Data

2. Meaningful Calculations
The level of measurement determines which statistical calculations are meaningful for that data. There are 4 levels of measurement.
Level of Measurement
Definition
Example
Meaningful Calculations
Nominal
(for qualitative data only)
Used with data where no math calculations can be made…only categorizing and labeling (LIST)
Major PGA Tournaments
- Put in a category
Ordinal
(for qualitative or quantitative data)
Used for data that can be arranged in order, but differences between data entries cannot be calculated
Motion Picture Association of America Rating Descriptions
Put in a category
Arrange in order

3. Meaningful Calculations
Level of Measurement
Definition
Example
Meaningful Calculations
Interval
(for quantitative data)
Used with data that can be arranged in order and can calculate differences in data entries. Data entry of 0 is an actual value.
Average Monthly Temperature for Sacramento, CA
Years / Time
Put in a category
Arrange in order
Find differences in values
Ratio
Same as interval level, but can calculate proportions or percents for comparison.
Data entry of 0 means none.
Average Monthly Precipitation for Sacramento, CA
Find ratios of values

4. Identify each data set’s level of measurement.
Nominal
1) A collection of phone numbers
2) The heart rate, in beats per minute, of an athlete who is exercising.
Ratio
3) The body temperature (OF) of an athlete who is exercising
Interval
Ordinal
4) The final standings of the Northeast Division of the NHL

5. Practice Problems
Pg 12 – 13 # 7 – 20 all