Information Technology - Data Processing
Data Processing is the method of converting of raw information into computer-based transferrable pieces of information. The processing is usually assumed to be automated and running on a mainframe, minicomputer, microcomputer or a personal computer.
Because data are useful when well-presented and actually informative, data processing systems are often referred to as information systems to emphasize their practicality. Nevertheless, both terms are roughly synonymous, performing similar conversions; data-processing systems typically manipulate raw data into information, and likewise, information systems typically take raw data as input to produce information as output.
More generally, the term data processing can apply to any process that converts data from one format to another, although data conversion would be the more logical and correct term. From this perspective, data processing becomes the process of converting information into data and also converting data back into information. The distinction is that conversion doesn’t require a question (query) to be answered.
Data are defined as numbers or characters that represent measurements from the real world. A Datum is a single measurement from the real world. Measured information is then algorithmically derived and/or logically deduced and/or statistically calculated from multiple data. Information is defined as either a meaningful answer to a query or a meaningful stimulus that can cascade into further queries.
Data are any facts, numbers, or text that can be processed by a computer. Today, organizations are accumulating vast and growing amounts of data in different formats and different databases. This includes:
1. Operational or transactional data such as sales, cost, inventory, payroll, and accounting
2. Non-operational data, such as industry sales, forecast data, and macroeconomic data
3. Metadata- data about the data itself, such as logical database design or data dictionary definitions.
Information is any useful record of event, transactions, data or facts represented by text formats and media formats. For example, analysis of retail point of sale transaction data can yield information on which products are selling and when.
Types Of Data
Think about any collected data that you have experience; for example, weight, sex, ethnicity, job grade, and consider their different attributes. These variables can be described as categorical or quantitative.
1. Categorical: This could be Nominal (no inherent order in categories) - examples are: Eye color, ethnicity, diagnosis. It could also be Ordinal (categories have inherent order) - Job grade, age groups, also Binary (2 categories – a special case of above) - Gender.
2. Quantitative (Interval/Ratio) (NB units of measurement used): This consists of Discrete (usually whole numbers) - Size of household (ratio), and Continuous (can, in theory, take any value in a range, although necessarily recorded to a predetermined degree of precision) - Temperature °C/°F (no absolute zero) (interval) Height, age (ratio).
Input, Processing, And Output
Whenever a computer is used, it must work its way through three basic stages before any task can be completed. These are input, processing, and output. A Computer works through these stages by running a program. A program is a set of step-by-step instructions that tells the computer exactly what to do with the input in order to produce the required output.
Input: The input stage of computing is concerned with getting the data needed by the program into the computer. Input devices are used to do this. The most commonly used input devices are the mouse and the keyboard.
Processing: The program contains instructions about what to do with the input. During the processing stage, the compute follows these instructions using the data which has just been input. What the computer produces at the end of this stage, the output will only be as good as the instructions given in the program. In other words, if garbage has been put into the program, garbage is what will come out of the computer. This is known as GIGO, or Garbage in Garbage Out.
Output: The output stage of computing is concerned with giving out processed data as information in a form that is useful to the user. Output devices are used to do this. The most commonly used output devices are the screen, which is also called a monitor or VDU and the printer.
Architecture Of The Computer System
This is the ‘brain’ of the computer. It is where all the searching, sorting, calculating and decision making takes place. The CPU collects all of the raw data from various input devices (such a keyboard or mouse) and converts it into useful information by carrying out software instructions. The result of all that work is then sent to output devices such as monitors and printers.
The CPU is a microprocessor - a silicon chip - composed of tiny electrical switches called ‘transistors’. The speed at which the processor carries out its operations is measured in megahertz (MHz) or Gigahertz (GHz). The higher the number of MHz the faster the computer can process information. A common CPU today runs at around 3 GHz or more. The Intel Pentium processor and the Athlon are examples of a CPU.
The Control Unit
The CU coordinates the work of the whole computer system and it has three main jobs:
1. It controls the hardware attached to the system. The Control Unit monitors the hardware to make sure that the commands given to it by the current program are activated.
2. It controls the input and output of data, so all the signals go to the right place at the right time.
3. It controls the flow of data within the CPU.
The Immediate Access Store
The IAS holds the data and programs needed at that instant by the Control Unit. The CPU reads data and programs kept on the backing storage and store them temporarily in the IAS’s memory. The CPU needs to do this because the Backing Store is much too slow to be able to run data and programs directly.
Arithmetic And Logic Unit
It is where the computer processes data by either manipulating it or acting upon it. It has two parts:
1. Arithmetic part - does exactly what you think it should - it does the calculations on data such as 3 + 2.
2. Logic part - This section deals with carrying out logic and comparison operations on data. For example, working out if one data value is bigger than another data value.