Chapter 3 - Data Types

Question 1

Explain the differences in these structured data types:

• Categorical data
• Numerical data

Answer 1

Categorical data

Classifies data into groups - Usually described with words

(certain categories can be numbers like invoice #)

Numerical data

Meaningful numbers that can be summated to create meaningful data

Question 2

What is this type of categorical data:

Nominal data

• Give some examples.
• How is it summarized?

Answer 2

Categorical data that cannot be ranked

Examples: Gender and transaction types

Summarized using counting and grouping.

Question 3

What is this type of categorical data:

Ordinal data

• Give some examples
• How can it be summarized?

Answer 3

Categorical data with natural “order” or rank

Examples: Letter grades or rank

Summarized with counting, proportion, and ranking

Question 4

What is this subcategory of numerical data:

Interval data

• Give an example
• How can this data be summarized?

Answer 4

Numerical data with equal intervals or distance between each observation but not definitive zero

Example: Temperature/SAT score

Can be summarized using:

• Counting/grouping
• Proportion
• Summing
• Averaging

Question 5

What is this subcategory of numerical data:

Ratio Data

Give some examples

Answer 5

Numerical data with an equal and definitive interval between each data and has definitive zero

Examples: Salary, Sales

Note: may allow for negative numbers (like returns)

This is different from interval data.

Question 6

What are these data types:

String/text/alphanumeric

Answer 6

String of characters (numbers and letters) that are interpreted as number of characters used.

Question 7

What are these data types as interpreted by Tableau:

• Dimension
• Measure

Answer 7

Dimension

Any data point that is determined to be categorical (by Tableau)

Measure

Any data point that is determined to be numerical (by Tableau)

Question 8

Why is receiving data “raw” the best?

Answer 8

Raw data is free of calculations.

Without an understanding of the fiels in a dataset, you would not know about the calculation.

Question 9

What type of data are product reviews (1-5 stars)?

Answer 9

Categorical:

Ordinal