Unit 1: Page 33: Processing data Flashcards
Explain the importance of data accuracy.
Inaccurate data leads to incorrect decisions being made.
What are two examples of the consequences of data inaccuracy?
- 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.
Methods of ensuring data accuracy data does not ensure data is 100% accurate but ensures data is what?
They ensure it is sensible and matches the original source.
List two types of methods to ensure data accuracy.
- Validation
- Verification
Describe what validation is.
Validation ensures data entered is sensible and reasonable.
List the 4 types of Validation checks.
- Type check
- Range check
- Length check
- Format check
Describe Type check and give an example.
- Data must be the correct type
- For example, data in a date of birth field.
Describe Range check and give an example.
- Numerical data must be between set values.
- For example, Age must be between 18 and 65.
Describe Length check and give an example.
- Data must be less than or greater than a certain number of digits.
- For example, first name must be less than 15 characters.
Describe Format check and give an example.
- Data must be in the correct predefines format.
- For example, Postcode must be LLN NLL.
Describe what verification is.
Verification ensures data entered matches the original source.
List two types of verification checks.
- Double entry check
- Proofreading check
Describe a Double Entry Check and give an example.
- Data must be entered twice and both entries must match.
- For example, entering a password twice on a registration form.
Describe Proofreading Check and give an example.
- 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.
What’s the 1st step for extracting and sorting data?
- Data is extracted from unstructured sources, such as web pages (web scraping), emails and documents.
What’s the 2nd step for extracting and sorting data?
- The data is entered into a system for processing.
What’s the 3rd step for extracting and sorting data?
- The data is stored in a database program to add structure.
What’s the last step for extracting and sorting data?
- The database can be sorted can be sorted and searched using SQL queries.
Describe what data modelling is.
Data modelling ensures that the database is correctly structured, allowing the data to be efficiently processed.
Describe numerical modelling.
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.
