Data and Information - Information Technology - AS

ICT systems input data which is processed to convert it to information

Some systems - result ouput fed back into the system. Modifying input until correct output is produced

Good quality information prodcued - used by humans - aid decision making process

What is data?

• Raw facts and figures or set of values
• Set of data may consist: 2,4,3,5,6
• Collected from examanation results such as 23,45,67,98

Types of data? (Bits and Bytes)

• Input, computers store and process data using binary numbers
• Single unit binary is called a 'bit' - stands for a binary digit
• Computer memory measured in 'bytes'.
• One byte made up of eight bits
• One byte can store once character

Coding and Encoding

• When data is collected it may need to be encoded. (fields on a paper based document)
• Necessary to code data - able to process it effectively
• Single digit needs to fed into the computer - number makes it easy to compare restarent with another one included in the survey
• Encoding - used by all computers - converts data into machine readable form
• Computer understand binary - difficult for humans to understand
• A way of encoding text is by using ASCII - represents each character as a binary number
• e.g. binary codes assigned to the QWERTY keyboard
• Some data coded before storage - changes original data into a shortened version by assingning code
• Coding (essential to keep it short, saves storage space, speeds up entry)
• Some coding examples: Gender: M or F for Male or Female, Questionnaire answers: Y or N for Yes and No
• Looses accuracy - colours coded as simple colours - takes up less memory on the system
• Codes can be difficult to remember. (remebering favourite book ISBN number)

Bar Codes

• Bar codes used in supermarkets -
• Leading role in stock control and customer ordering - web based commerce in warehousing
• Seen in form of UPC (Universal Product Code) - several varities - most common in the UK and European Article Number 13/18 digit.
• Series of bars and spaces represent the code…