Data and information

Information and data By the end of this, you should be able to state the difference between DATE and INFORMAITON.

What's the diffrence Information systems = hardware and software working together It will take DATA that has been INPUT and converted it into INFORMATION In other words and information system processes the DATA to produce INFORMATION

Define the difference Data is raw facts and figures which have no meaning and have not been put into a context (given a purpose) Example: this is a set of data 85,60,65,90,70,50,40. As it is, it has no meaning, the numbers could mean anything (within reason). It becomes information when given a purpose or put into content.

Define the difference The DATA as now become INFORMATION since it has been given a meaning… INFORMATION occurs when DATA has been PROCESED… *processed means taking the values and manipulation them (doing something with them)

Define the difference Information is data which has been processed to give it meaning. When we have information we can come up with conclusions and answer questions about the data Information = data + context + meaning

Define the difference If the average mark of the class is calculated, the data will give the teacher some useful information… …ICT system produce information which has been formatted so that a user can make use of it (understand it)… …information can be paper-based e.g. a report or electronic e.g. a chart shown on a screen.

Data All data is stored in a table A database is a persistent collection of data or information which is held together in an organized or logical way. Lots of tables create a relational database. Data stored in a relational database are linked together e.g. address books.

Database examples: Google SIMS (school registers) Yellow pages Mobil phones Electoral registers

Each field must be specified as a data type

Key The primary key is put on the field that distinguishes items from the others

Data capture and Data Input Data must first be ‘captured’ (collected in a way that then makes it easy to input) Data must be input into the computer The system analyst will select a data capture method and data input method that best suit the requirements of the new system. Sometimes the two steps of data capture and data input are performed at the same time. For example a barcode reader captures the data (the numeric code on the barcode) and inputs it to a computer

Choosing thee best data capture and data input methods for the system Collecting data into a form that is ready for input to a computer system can be done in many ways… Paper Forms: Form can be a simple one with spaces for numbers and text to be written in. The data from this from would then be typed into the computer Barcode Reader: Barcode reader capture the numeric code that the barcode represents. Typically used with POS systems and also stock-control systems Card Reader: Many cards contain data stored on a magnetic strip or in a small bit of memory (smart cards) which can be captured with a card reader

Data Entry As a data is entered into the system, it needs to be checked for accuracy. Two techniques help us do this: validation and verification

Data Verification Techniques Data validation only checks whether the data entered is sensible – it does not mean that the data is the right data For example Correct date of birth: 12/11/1982 Date of birth entered: 12/11/1928 …you would not see an error, since 12/11/1928 is a valid date of birth. To check that the data is the correct value, we use a system called data verification. Proof reading After the data has been entered a person compares the original data in the computer (either on the screen or use a print-out) If mistakes are spotted they can be corrected be the same person. Proof –reading is quick and simple, but doesn't catch every mistake

Double-entry The data is entered into the computer twice (preferably by the two different people) The computer compares the two sets of data to see if they match. If not it generates an error and a person will need to correct the mistakes. Double-entry takes more time and effort, but it catches almost every mistake.