MTA 98-364 Theory: Data Information and Knowledge

A definition of data

Data is processed by computers, the resulting information can then be used to form judgments and make predictions.

Data is words, numbers, dates, images, sounds etc without context.

This is a list of data items:

• 42
• rabbits
• 16:00
• 76
• apples
• 09743245530
• £40
• seaside

A definition of information

Information is a collection of words, numbers, dates, images, sounds etc put into context, ie to give them meaning.

For example, take these data items from the previous page:

• 42
• rabbits
• 16:00
• 76
• apples
• 09743245530
• £40
• seaside

When used to form part of a sentence they gain meaning:

• there are 42 apples in that box and each one of them has been nibbled by rabbits
• the fare to the seaside is £40 and the journey takes 76 minutes by rail
• my telephone number is 09743245530, call me at 16:00.

This is information - data put into context.

Changing data into information

A structure is needed in order for data to become information. In the table below the second and third columns contain either 'Yes' or 'No' but without headings there is no meaning.

Stef	Yes
Jamal	Yes
Adam	Yes
Kieran	Yes
Dylan	Yes
Sophie	No	Yes
Max	No	No

By adding headings, the data becomes information.

Student name	Present	Absence authorised
Stef	Yes
Jamal	Yes
Adam	Yes
Kieran	Yes
Dylan	Yes
Sophie	No	Yes
Max	No	No

Input devices can collect data automatically, eg sensors that continually measure a temperature or a fix-mount barcode reader at a till.

In both of these cases the data collected will be read into a databasefor processing. With a structure in place (the database) the data becomes information.

Spreadsheets are commonly used to turn data into information.

A definition of knowledge

Knowledge is the ability to understand information and to then form judgements, opinions, make predictions and decisions based on that understanding.

Knowledge from information

Example 1

Each year, for the past five years, the apple crop in Somerset has grown by 10%. The same amount of growth is predicted this year so we need to find markets for a further 10% of apples.

In this example, data collected each year, for the past five years, has become information and a pattern in the growth of the apple crop has been identified - 10% year on year. This information has been used to predict the same level of growth this year and has highlighted the need for more markets. The prediction and realisation are knowledge, ie the use of information.

Example 2

The car looked like it had flat tyres and it had a pool of petrol underneath it at the back. There was smoke coming from the bonnet. I took the decision not to allow anyone near it and to evacuate the area.

In this example the judgement made and the decision that followed, ie to evacuate the area, is the knowledge, gained after assessing the available information.

Data leads to information, and information leads to knowledge.

Expert systems

Computers can be programmed with rules to use information to make simple decisions. This is knowledge that has been passed on from the programmer. A simple example of this is a spreadsheetapplicationthat monitors pupils' test marks and calculates average scores.

A more sophisticated example of this is an expert system. This is where computers are programmed to accept a large number of items of information and, based on rules set in the program, make decisions, then further decisions.

The best-known examples of these are automatic pilots in aeroplanes and diagnosis applications used to help doctors. In both cases these systems are only as good as the rules programmed by the human computer programmer and cannot deal with the unexpected. They need to be used as aids to human decision making only. The actual doctor must confirm a diagnosis and treatment suggested by an expert system.