What is valid data?
Valid data is data that makes sense logically, even if it was entered incorrectly. For e.g. my birthday is not 11/04/2002 but that makes sense logically.
What are some examples of data verification?
- Visual checking
- Double entry of data
What are some examples of data validation?
- Data type checks, e.g. letters not entered into a number field
- Presence checks
- Format checks, e.g. right length
- Range checks (numbers)
- Look-up lists
- Check digits, last number in a code is the answer to a complex calculation
What is a parity check?
Parity checks ensure that data transmission between nodes during communication is accurate.
What is a node?
A node can be a computer or some other device, such as a printer. Every node has a unique network address.
What are hash and batch totals?
Numerical sums of fields in a file, including data that isn’t usually used in calculations, for e.g. account numbers. Recalculations are compared with the original answer to see if data has been lost or changed.
What are some components of a spreadsheet?
- Labels
- Data
- Formulas & functions
What is relative cell referencing?
Typing, e.g. =A1, and using the fill handle to replicate the values that are in column A.
What is absolute cell referencing?
Absolute cell referencing is used when you want a value in a calculation to remain constant.
What are some benefits of using a spreadsheet?
- What-if calculations allow businesses to predict income/profits
- Automatic recalculation
- Accurate calculation
- Can produce graphs & charts easily
What are some methods of data capture?
- Chip and pin, captures card details and compares with pin code
- Optical mark recognition (OMR), e.g. marks on a lotto ticket
- Bar code reading
- Voice recognition
- Biometrics
- Radio Frequency Identification (RFID) Tags, data stored on a chip that can be read at a distance or through material
What are some components of a database?
- Fields, allow records to be uniquely identified
- Records, a set of records constitutes a file
- Tables, store info
- Flat files, contain a single table of data
- Relational databases, contain multiple tables of data that relate to each other
What is data redundancy?
The repetition of data, which takes up storage
What are some types of data handling systems?
- Financial forecasting
- Weather forecasting
- Flight simulators
- Decision making systems
What are operators?
Ways to find data using the symbols =, >, , >=, <=.
for e.g. Search for all shirts where size = XL and price <= £10
