Computer processing involves manipulating the symbols that people use to represent things. The first computers were built to manipulate numbers in order to solve arithmetic problems. But, we create, use, and manipulate many other symbols that represent the facts of our lives. Luckily for us, early computer experts soon made the important discovery that a machine can accept store, and process numbers can also manipulate nonnumerical symbols. Manipulating these familiar symbols is possible if an identifying code number is assigned to the symbol to be stored and processed. Thus, the letter A can be represented by a code, as can the letter B, the addition symbol (+), and so on. Of course, someone must give the computer instructions if it is to manipulate the coded and stored symbols in a desired way. Instructions are needed, for example, to put a stored list of names into an alphabetical sequence.
Data processing consists of gathering the raw data input, and evaluating and bringing order to it, and placing it in proper perspective so that the useful information will be produced. All data processing, whether done by hand or by the latest computer system, consists of three basic activities: capturing the input data, manipulating the data, and managing the output results.
CAPTURING THE INPUT DATA. Data must be originated in some form and verified for accuracy prior to further processing. They may initially be recorded on paper source documents and then converted into a machine-usable form for processing. Or they may be captured by a direct input device in a paperless machine-readable form.
MANIPULATING THE DATA. One or more of the following operations may be performed on gathered data:
Classifying = organizing similar items into
groups or classes.
= is usually accomplished by assigning predetermined abbreviations or codes to the items being arranged.
3 TYPES OF CODES USED:
Sorting = arranging classified data in such a sequence
Calculating = arithmetic manipulation of the data
Summarizing = reducing masses of data to a more concise and usable form.
MANAGING THE OUTPUT RESULTS. Once the data have been captured and manipulated into a one or more of the following operations may be needed:
Sorting and retrieving = retaining data for future reference is sorting. Recovering stored data and/or information is the retrieving activity
Communicating and reproducing = transferring data from one location or operation to another for use or for further processing is data communication- a process that continues until information, in a usable form, reaches the final user.
PROCESSING BY COMPUTER. The four function categories,
which follow, are all computer performed, but they include most data processing
Input output operations = a computer can accept data (input) from and supply data (output) to a wide range of input output devices.
Calculation Operations = the circuits in a computer are designed to perform addition, subtraction multiplication and division.
Logic/comparison operations = the computer also has the ability to perform logic operations. This simple ability to compare is an important computer property because more sophisticated questions can be answered by using combinations of comparison decisions.
Storage and retrieval operations = both data and
program instructions are stored internally in a computer. Once stored,
both may be quick called up , or retrieved for use.