Elementary StatisticsPicturing the World

Data Classification

1.2 Data Types and Levels of Measurements Qualitative data – consist of values that

describe qualities or non-numerical (i.e. brand names, letter grades)

Quantitative data – consist of values representing counts or measurements (i.e. social security numbers, percentage grades)

1.2 Data Types and Levels of Measurements

Four Levels of Measurement: Nominal – data consisting of names, labels, or categories

only. The data are qualitative and can not be ranked or ordered

Ordinal – qualitative or quantitative data that can be arranged in some order. It generally does not make sense to do computations with ordinal data.

Interval – quantitative data which intervals are meaningful, but ratios are not. Data at this level have an arbitrary zero point.

Ratio – quantitative data which both intervals and ratios are meaningful. Data at this level have a true zero point.

1.2 Data Types and Levels of Measurements

Four Levels of Measurement: Nominal – Flavors, gender, type of car you drive,

occupation

Ordinal – Movie ratings ( 3 stars vs. 2 stars)

Interval – temperature (55 degrees is more than 11 degrees, but 55 degrees is not necessarily 5 times hotter than 11 degrees because 0 does not represent no temperature)

Ratio – distances (10 miles is twice 5 miles, and 0 miles means no distance), salary, age

1.2 Data Types and Levels of Measurements

1.2 Data Types and Levels of Measurements

Eye color on a dating survey?

A. Qualitative

B. Quantitative

1.2 Data Types and Levels of Measurements

Scores on a multiple choice exam?

A. Qualitative

B. Quantitative

1.2 Data Types and Levels of Measurements

Flavors of ice cream?

A. Qualitative

B. Quantitative

1.2 Data Types and Levels of Measurements

College majors?

A. Qualitative

B. Quantitative

1.2 Data Types and Levels of Measurements

Weights of trucks?

A. Qualitative

B. Quantitative

1.2 Data Types and Levels of Measurements

Incomes of college graduates?

A. Qualitative

B. Quantitative

1.2 Data Types and Levels of Measurements

The numbers on the shirts of a girl’s soccer team?

A. Qualitative

B. Quantitative

definite order

1.2 Data Types and Levels of Measurements

Student rankings of cafeteria food: excellent, good, fair, poor?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

true zero point

1.2 Data Types and Levels of Measurements

Weights of wrestlers?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

because dates have no meaningful ratios and zero does not represent beginning of time

1.2 Data Types and Levels of Measurements

Calendar years of historic events, such as 1776, 1945, 2001?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

no ordering

1.2 Data Types and Levels of Measurements

Numbers on uniforms?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

because temperature has no meaningful ratios and zero degrees does not mean “no heat”

1.2 Data Types and Levels of Measurements

Temperatures on the Celsius scale?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

true zero point

1.2 Data Types and Levels of Measurements

Runner’s times in the Boston Marathon?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

1.2 Data Types and Levels of Measurements

Data that can be classified according to color?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

1.2 Data Types and Levels of Measurements

The final grades (A, B, C, D, and F) for students in a Probability & Statistics course?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

1.2 Data Types and Levels of Measurements

A list of Zip Codes?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

1.2 Data Types and Levels of Measurements

The daily temperatures (in degrees Fahrenheit) on five randomly selected days are 22, 21, 31, 36, 21?

A. Nominal

B. Ordinal

C. Interval

D. Ratio

1.2 Data Types and Levels of Measurements

Social Security Numbers?

A. Nominal

B. Ordinal

C. Interval

D. Ratio