Encoding and coding data

Encoding needs to happen when data is collected. An example would be for fields on a paper-based document.

Data is often needed to be coded in order for it to be processed effectively. Value judgements are a good example of this. If as part of a survey you ask 100 people how good they think a resturant is, they will all most probably give a different answer. This makes it very hard to enter as data in order to analyse it further. However if they were asked to rate the resturant on a scale of 1 to 5, where on is excellent and 5 is very poor. This would mean that after all the data is collected only a single digit needs to be entered into the computer and the fact that is a single number makes it much easier to compare the resturant with another one already included in the survey.

Encoding Data

Computers use encoding to convert the data into a machine readable form. Even though its difficult for humans to understand, all computers can understand is binery's, 1's and 0's. Due to the fact that as humans cant understand this for us to use computers the data must be encoded into binary for a computer to process and share, e.g. encoding our language into a machine-readable form

A way of encoding text is by using ASCII to represent each character as a binary number.

Coding

Data can sometimes be coded before storage this changes the data into a shortened version by assigning a code. Data is coded essentially to keep it short, which saves storage space but also speeds the process up.

Some condings that you may be familiar with are:

Gender: M or F for Male or Female

Questionnaire answers: Y or N for Yes and No

To be made shorter during coding the colours below could be said to be blue, green, red and brown instead of the orginal colours of royal blue, emerald green, vivid red and chocolate brown.

However when the names are being shortened down this could result in the data losing some of its accuracy because not matter what colour blue it is even if it is light blue it will still just be named blue. Also some codes can be difficult to rememeber for example ISBN (International Standard Book Number) rather than its title!


Bar Codes


A main set of data which everyone must have come across is a bar code. These can play a leading role in stock control and customer ordering for web-based commerce in ware-housing. They are seen in many different forms e.g. UPC which is a Universal Product Code. However the most common form in the UK is EAN 13 which stands for European Article Number 13 digits and EAN 18 which stand for the same thing apart from 18 digits instead. The data is represented by a series of bars and spaces which are read by a bar-code scanner.

Bar codes are very versatile and can be read from many different angles and even upside down! All different products will have a unique number which is allocated by the European Article Number Association. Places where bar codes are used are student cards, products in warehouses and of course supermarkets. The output after the barcode has been scanned is the product description and the price will be shown on the monitor and printed out on a receipt.

Another coding system seen on books is known as the ISBN. This is very similar to a bar-code and all books are allocated a unique number which is called the composite code. Most ISBN codes use the same format as a bar code, which makes stock control much easier than traditional methods.