How data can arise, coding, encoding and encryption, Quality of data

How data can arise, coding, encoding and encryption, Quality of data

1. How data can arise

   • Indirect data capture - data that is used for a purpose other than its original
   • Direct data capture - data are entered/input directly into a system for a specific purpose

2. Coding

   • Data is coded BEFORE it is input because it is quicker to input, easier to validate, takes up less space.
   • Example  - in a questionnaire female = f, male = m, dates = 01/01/2016, London Heathrow = LHR

3. Encoding

   • Encoding - Data needs to be converted into a machine readable format so the computer can understand it. Encoding also compresses data.
   • Example - images may be encoded into an compressed bitmap using a jpeg file format, this enables the image to be read by the computer and viewed on screen or printed

4. Encryption

   • When data is encrypted it is scrambled using an encryption key so that it cannot be read by anyone who does not have the decryption key
   • Example, when you enter your debit card details into an e-commerce website to buy products, the important data is scrambled so only the bank see it using their decryption key

5. Quality of data

   • Up to date - In order to be useful, information needs to be up-to-date. In many cases information changes over time and so old or out-of-date information can be misleading or give you the wrong picture of what is happening.
   • Relevant for a particular use - In order for information to be useful it must be relevant to you.
   • Accuracy - If the data that you have collected is inaccurate then the information it will produce will inevitably also be inaccurate.
   • Reliable source - information source it is reliable and can be trusted.
   • Complete - In order for information to be useful it needs to be complete. If parts of the information is missing then you will not be able to make use of it or make accurate decisions.