Data, Information and Information Management

The shoebox is full of data: raw, recorded facts with no context attached. "12/03, Emeka, 2 cartons Indomie, ₦18,400, unpaid" is data. On its own it does not tell Mama Ngozi anything she can act on.

Data are raw facts and figures that describe events, objects or people, recorded without interpretation. Information is data that has been processed, organised and given context so that it is meaningful and useful for decision-making.

When she adds up every unpaid receipt per customer and sorts the list from largest to smallest debt, the same data becomes information: "Emeka owes ₦96,000 across seven visits; chase him first." Processing (selecting, sorting, summarising, comparing) is what turns one into the other.

Many textbooks extend the idea into a ladder called the DIKW hierarchy: data → information → knowledge → wisdom. Knowledge is information combined with experience, so that patterns are understood ("customers who buy on credit in January usually pay after the February salary"). Wisdom is the judgement to act well on that knowledge ("stop giving credit to new customers in December"). Database systems mostly live on the bottom two rungs: they store data reliably and help turn it into information. Analysts and managers climb the rest of the ladder.

Not all information is equally useful. A report that arrives a week after the decision was made is worthless, however accurate. The qualities of good information are usually listed as:

• Accurate: free from errors; it truly reflects the data.
• Complete: contains everything needed for the decision.
• Timely: available when it is needed, not after.
• Relevant: related to the question being asked.
• Reliable and verifiable: can be checked against its source.
• Concise and clear: presented so the user understands it quickly.
• Accessible and secure: available to authorised people, and only to them.
• Cost-effective: worth more than it cost to produce.

Once an organisation depends on information, it has to manage it as deliberately as it manages money or staff. Information management is the collection, storage, organisation, retrieval, protection, distribution and eventual disposal of an organisation's information so that the right people get the right information at the right time.

It covers the whole life of a piece of information, often drawn as a cycle. The diagram below shows the stages, which also map neatly onto the units of this course.

Each stage raises its own questions. Capture: how do we get facts in accurately? Storage: where do they live, and how do we stop them being lost? Organisation and indexing: how do we find one record among ten million in a fraction of a second? Retrieval and analysis: how do we ask questions of the data? Sharing and protection: who may see what, and how do we respect people's privacy? Disposal: how long must records be kept, and how are they destroyed safely?

A database management system answers most of these questions in one piece of software, which is why databases sit at the centre of almost every modern organisation, from a bank in Lagos to the national identity register.