 At the end of the class students should:  distinguish between data and information.  explain the characteristics and forms of Information Processing in a wide range of contexts  identify the sources  Explain how data is validated and verified.  Describe how files are organized.  select the best forms of file organization for particular application.

 Data are facts that have not yet been organised or processed.  Information is what you get when data are organised in a useful form

 A collection of cards noting the meaning of words would be data. But if the words were organised into a single document, in alphabetical order, this makes a useful dictionary.  You might note all your friends’ names and phone numbers down, but if they are organised into electronic list, this can be used as the directory of a mobile phone.

 Data are collected and input in many ways.  Some raw data are collected automatically, for example by electronic sensors.  Typing  They are document systems set up to collect and prepare data for computer processing.

 When collecting data, people typically use a structured document such as  A source document is a structured form used by doctors, scientist and other medical staff etc.  A turnaround document is a form that is printed out by the computer, and then used to collect data.  Machine-readable documents. Some data – such as bar codes – are design to be input directly into computer without typing.  Human – readable documents. It can be most useful to have document that can be read by people and machine.

 Human beings can easily make mistake. For this reason checks are often carried out to make sure there are no errors.  Types of error(typographical error)  Spelling  Typing the wrong key( especially if the key are beside each other)  Transposition error(typing characters in the wrong order)  Pressing of the shift key (eg. Typing 3 instead of #)  Mixing up numbers and similar looking letters(eg. 1 and I ot 0 and o)

 Proofreading – If you are typing text it is easily to spot your spelling mistake by reading your document carefully, on the screen. Word processing software includes spell checking facility to aid the user.  Data verification – This takes place when a person checks that data has been correctly keyed into the computer system.  Double entry verification - This is a common method of data verification in which the data is keyed in a second time, and the first entry is checked against the second.

 Validation – This ensure the data is valid. Valid means the data are of the right general type or value. The main types of validation are:  Data type – The computer checks that the data are of the right type.  Range – The computer checks that the data are within a sensible range of numbers.  Field Length – The number of character held in each field.  Consistency – The computer might check the data entered against records.  Reasonableness – Depending on the type of information you are entering the computer can carry out a number of other checks that your data are reasonable.

 All information is stored in the computer in named files. Any type of information can be stored as a file:- document, picture, sound clip or video clip.  Storage media  The most common storage media are:  Hard disk drive  Flash memory  CD  DVD  Tape

 Serial access file – The data records are stored as a series, one after the other. To find information the software needs to look through every record, one at a time.  Sequential access file – is similar to serial access file but the records are sorted in a particular sequence.  Indexed sequential access file – It is sorted in a particular order – typically code number order.  Direct or random access file – This will allow the computer to immediately access the location in memory where any record is stored.

 Information(or data) processing refers to computer-based systems that take in data and generate information.

 Industrial and manufacturing business need to carry out all the business task such as:  Control systems – controlling the process used when manufacturing products.  Computer Aided Design – designing products.  Computer Aided Engineering and Computer Aided Manufacture – using special software to develop and test products.

 Computer systems are used in many business to carry out some time-consuming administrative task.  Examples are  Payroll  Orders  Sales  Invoices  Payments  Accounts  Budget  Correspondence  Marketing  Security

 Batch Processing – This is use in the commercial environment to process a great deal of data. e.g. Payroll, bills etc.(in most cases it is done overnight).  Information retrieval – This is use to locate a single piece of information in a great mass of data. e.g. transacting at a ATM machine  Information management – When data is organized in a structural way it is easier to find and retrieve the necessary information.  Real-time processing –This is data processing that appears to take place, or actually takes place, instantaneously upon data entry or receipt of a command.

 Scientist can gather a lot of data during an experiment. Sometimes they will use sensors to capture data over a period of time.