Unit 1: Page 33: Processing data

Question 1

Explain the importance of data accuracy.

Answer 1

Inaccurate data leads to incorrect decisions being made.

Question 2

What are two examples of the consequences of data inaccuracy?

Answer 2

• Incorrectly recorded stock levels could lead to ordering too little or too much stock.
• Inaccurate traffic information could lead to being late for an interview.

Question 3

Methods of ensuring data accuracy data does not ensure data is 100% accurate but ensures data is what?

Answer 3

They ensure it is sensible and matches the original source.

Question 4

List two types of methods to ensure data accuracy.

Answer 4

• Validation
• Verification

Question 5

Describe what validation is.

Answer 5

Validation ensures data entered is sensible and reasonable.

Question 6

List the 4 types of Validation checks.

Answer 6

• Type check
• Range check
• Length check
• Format check

Question 7

Describe Type check and give an example.

Answer 7

• Data must be the correct type
• For example, data in a date of birth field.

Question 8

Describe Range check and give an example.

Answer 8

• Numerical data must be between set values.
• For example, Age must be between 18 and 65.

Question 9

Describe Length check and give an example.

Answer 9

• Data must be less than or greater than a certain number of digits.
• For example, first name must be less than 15 characters.

Question 10

Describe Format check and give an example.

Answer 10

• Data must be in the correct predefines format.
• For example, Postcode must be LLN NLL.

Question 11

Describe what verification is.

Answer 11

Verification ensures data entered matches the original source.

Question 12

List two types of verification checks.

Answer 12

• Double entry check
• Proofreading check

Question 13

Describe a Double Entry Check and give an example.

Answer 13

• Data must be entered twice and both entries must match.
• For example, entering a password twice on a registration form.

Question 14

Describe Proofreading Check and give an example.

Answer 14

• Data must be read through to ensure there are no data entry errors
• For example, A checkbox asking you to confirm the data entered is correct.

Question 15

What’s the 1st step for extracting and sorting data?

Answer 15

1. Data is extracted from unstructured sources, such as web pages (web scraping), emails and documents.

Question 16

What’s the 2nd step for extracting and sorting data?

Answer 16

2. The data is entered into a system for processing.

Question 17

What’s the 3rd step for extracting and sorting data?

Answer 17

3. The data is stored in a database program to add structure.

Question 18

What’s the last step for extracting and sorting data?

Answer 18

4. The database can be sorted can be sorted and searched using SQL queries.

Question 19

Describe what data modelling is.

Answer 19

Data modelling ensures that the database is correctly structured, allowing the data to be efficiently processed.

Question 20

Describe numerical modelling.

Answer 20

Correctly stored data can be used in numerical modelling, This involves simulating systems to help analyse data and make predictions such as weather models used to forecast future weather patterns.