Aug 02 2009
Collection of Data
We can collect data directly:
- An employee clocks on with a punched card
- Voltage and current are sensed with voltmeter and ammeter sensors
- A library book’s bar code is scanned into the computer.
- Credit card transactions are logged so that the monthly bill is sent to the account holder.
This is often called data capture.
Data can be collected indirectly. It is used for a purpose other than the original purpose. For example, the transaction data for a credit card holder can be used to build up a profile of the customer. The bank sells details of the customer to companies that market products and services that the customer is most likely to use.
It is obviously important that the data is accurate, up-to-date, and complete, but we can think of occasions when it has not been. This might lead to
- Simple amusement, e.g. a wildly wrong spelling of a name.
- Considerable distress and inconvenience, for example a person might be given a bad credit rating due to a mistake in a data entry, and their mortgage application is rejected.
- A dangerous situation, e.g. two aeroplanes heading straight for each other.
Keeping data so that it is high quality is important to a business. Mistakes can be expensive; an annoyed customer will take her trade elsewhere. However the maintenance of data is an ongoing and expensive activity:
- Customers move,
- Companies go bankrupt,
- New companies start.
- Rates for a service change all the time.
An insurance broker would be keen to give the best rates possible for his clients. He will have a database with all the insurers he uses. However they are changing rates and products all the time, so to keep abreast, he will have to have someone constantly updating the database.
A current radio advert starts:
“I am Michelle. I am Michelle. I am 37. I am 44. I am happily married. I have recently divorced. I am a home maker. I work for an industrial die manufacturer in Reading…”
The company whose radio advert this is makes its living by making sure that the databases of large organisations are kept up to date. While addressing a letter to Michelle and her ex might not be the biggest disaster in the world, it would probably cause Michelle no end of annoyance. Annoyed customers will take their trade elsewhere.
Any subjective description of something is based on a value judgement. Some people might describe another person as “rude and bad-mannered”, whereas others might describe the same person as “good laugh”. One person might gain a lot from a particular computing lesson; for another it could be a complete turn off. Questionnaires try to code value judgments. You tick boxes marked from Excellent to Very Poor. This can be difficult, especially when you are asked to tick one box only, but your judgement lies between two boxes!
This is an example:
