Chapter 22

Question 1

What is quantify

Answer 1

Measurement of quantity

Question 2

Does data quantify subjectivity or objectivity

Answer 2

On both

Question 3

What are methods for data quantify objectively

Answer 3

• Dependent

- Independent

Question 4

What is independent objective data quantification

Answer 4

Data is independent. Data does not effect by organization rules

Question 5

What is dependent objective data quantification

Answer 5

Data is dependent and effect by organization rules

Question 6

Please tell more data dimension

Answer 6

• Believability
• Appropriate amount of data
• Timeliness
• Accessibility
• Objectivity
• Interpretability
• Uniqueness

Question 7

What are data quality assessment techniques

Answer 7

• Min-max
• Simple ratio
• Weighted average

Question 8

What is positive simple ratio

Answer 8

It is the ratio of desirable records with reference of total number of records subtract from 1

Question 9

What is negative simple ratio

Answer 9

It is the ratio of undesirable records with reference of total number of records subtract from 1

Question 10

What simple ratio is used in longitudinal analysis

Answer 10

positive simple ratio

Question 11

What is min-max data quality assessment technique

Answer 11

It relates to set of data and min or max of them. First we convert attributes of data normalize and then we take min max. When we take minimum value we are conservative and when we take maximum we are liberal.

Question 12

What is free of error ratio:simple ratio

Answer 12

Negative simple ratio

Question 13

What is completeness of data:simple ratio

Answer 13

Completeness of data can be measured through 3 aspects.
1- Schema
2- Column completeness
3- Population

Question 14

What is consistency:simple ratio

Answer 14

There are 2 types of consistency
1- Variation (e.g. karachi, khi, KHI, Karachi)
2- Functional integrity

Question 15

What are min-max measurements

Answer 15

• Believability
• Appropriate amount of data
• Timeliness
• Accessiblity

Question 16

Does believability a minimum (conservative) value

Answer 16

Yes

Question 17

What is the formula of timeliness

Answer 17

Max {0, 1-CM}
C = A + Dt - It
(Dt = Delivery time, It = Input time)

Question 18

What is formula of accessibility

Answer 18

Max {0, 1-trd/tru}

Question 19

What comes first assessment or validation

Answer 19

assessment

Question 20

What are methods for validation

Answer 20

1- Referential integrity validation (records without reference)
2- Attribute domain validation
3- Business rules
4- Analyze data

Question 21

What is data profiling

Answer 21

Data profiling is the process of examining the data available from an existing information source (e.g. a database or a file) and collecting statistics about that data.

Question 22

What are orphan records

Answer 22

Records without reference

Question 23

What are 3 steps for attribute domain validation

Answer 23

Step 1- Capture and quantify
Step 2- Compare
Step 3- Investigate

Question 24

What is histogram

Answer 24

History of data in DWH. It can be represented in graph form.