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Sir Naseem Ahmed KhanSir Naseem Ahmed Khan

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DataDataDataDataThe word data is derived from Latin language. It is The word data is derived from Latin language. It is

plural of Datum (But Data is usually used as a plural of Datum (But Data is usually used as a singular term.) Datum (singular) – Data (plural). singular term.) Datum (singular) – Data (plural).

Data is any collection of facts of figures. The data Data is any collection of facts of figures. The data is the raw material to be processed by a is the raw material to be processed by a

computer.computer.ExampleExample

Names of students, marks obtained in the Names of students, marks obtained in the examination, designation of employees, examination, designation of employees,

addresses, quantity, rate, sales figures or addresses, quantity, rate, sales figures or anything that is input to the computer is data. anything that is input to the computer is data.

Even pictures, photographs, drawings, charts and Even pictures, photographs, drawings, charts and maps can be treated as data. Computer processes maps can be treated as data. Computer processes

the data and produces the output or resultthe data and produces the output or result

Types of DataTypes of DataMainly Data is divided into two types:Mainly Data is divided into two types:

1. Numeric Data1. Numeric Data2. Character Data2. Character Data

1. Numeric Data1. Numeric DataThe data which is represented in the form of numbers is known The data which is represented in the form of numbers is known

as Numeric Data. This includes 0-9 digits, a decimal point as Numeric Data. This includes 0-9 digits, a decimal point (.), +, /, – sign and the letters “E” or “D”. (.), +, /, – sign and the letters “E” or “D”.

2. Character Data2. Character DataCharacter data falls into two groups.Character data falls into two groups.

i. String Datai. String Dataii. Graphical Dataii. Graphical Data

String DataString DataString data consists of the sequence of characters. String data consists of the sequence of characters. Characters may be English alphabets, numbers or space. Characters may be English alphabets, numbers or space. The space, which separates two words, is also a character. The space, which separates two words, is also a character. The string data is further divided into two types.The string data is further divided into two types.a. Alphabetic Dataa. Alphabetic Datab. Alphanumeric Data b. Alphanumeric Data

Graphical DataGraphical DataIt is possible that pictures, charts and maps can be treated It is possible that pictures, charts and maps can be treated as data. The scanner is normally used to enter this type of as data. The scanner is normally used to enter this type of data. The common use of this data is found in the National data. The common use of this data is found in the National Identity Card. Identity Card.

InformationInformationA collection of data which conveys some meaningful A collection of data which conveys some meaningful

idea is information. It may provide answers to idea is information. It may provide answers to questions like who, which, when, why, what, and how.questions like who, which, when, why, what, and how.

oror

The raw input is data and it has no significance when it The raw input is data and it has no significance when it exists in that form. When data is collated or exists in that form. When data is collated or organized into something meaningful, it gains organized into something meaningful, it gains significance. This meaningful organization is significance. This meaningful organization is informationinformation

oror

Observations and recordings are done to obtain data, Observations and recordings are done to obtain data, while analysis is done to obtain informationwhile analysis is done to obtain information

Data ProcessingData Processing

Data processing:Data processing:

Any operation or set of Any operation or set of operations performed upon data, operations performed upon data, whether or not by automatic whether or not by automatic means, such as collection, means, such as collection, recording, organization, storage, recording, organization, storage, adaptation or alteration to adaptation or alteration to convert it into useful convert it into useful information. information.

Data Processing CycleData Processing Cycle

Once data is collected, it is processed to convert Once data is collected, it is processed to convert it into useful information. The data is processed it into useful information. The data is processed again and again until the accurate result is again and again until the accurate result is achieved. This is called data processing cycle.achieved. This is called data processing cycle.

The data processing is very important activity The data processing is very important activity and involves very careful planning. Usually, data and involves very careful planning. Usually, data processing activity involves three basic processing activity involves three basic activities.activities.

1.1. Input Input 2.2. Processing Processing 3.3. OutputOutput

Data Processing CycleData Processing CycleStep-1Step-1

1. 1. InputInputIt is the process through which collected data is It is the process through which collected data is

transformed into a form that computer can understand. transformed into a form that computer can understand. It is very important step because correct output result It is very important step because correct output result totally depends on the input data. In input step, totally depends on the input data. In input step, following activities can be performed.following activities can be performed.i) i) VerificationVerification

The collected data is verified to determine The collected data is verified to determine whether it is correct as required. For example, the whether it is correct as required. For example, the collected data of all B.Sc. students that appeared in final collected data of all B.Sc. students that appeared in final examination of the university is verified. If errors occur examination of the university is verified. If errors occur in collected data, data is corrected or it is collected in collected data, data is corrected or it is collected again.again.ii) ii) CodingCoding

The verified data is coded or converted into The verified data is coded or converted into machine readable form so that it can be processed machine readable form so that it can be processed through computer.through computer.iii) iii) StoringStoring

The data is stored on the secondary storage into a The data is stored on the secondary storage into a file. The stored data on the storage media will be given file. The stored data on the storage media will be given to the program as input for processing.to the program as input for processing.


2.2.ProcessingProcessing The term processing denotes the actual data manipulation The term processing denotes the actual data manipulation techniques such as classifying, sorting, calculating, summarizing, techniques such as classifying, sorting, calculating, summarizing, comparing, etc. thatcomparing, etc. thatconvert data into information.convert data into information.

i) i) ClassificationClassificationThe data is classified into different groups and subgroups, so that each The data is classified into different groups and subgroups, so that each group or sub-group of data can be handled separately.group or sub-group of data can be handled separately.ii) ii) StoringStoringThe data is arranged into an order so that it can be accessed very The data is arranged into an order so that it can be accessed very quickly as and when required.quickly as and when required.iii) iii) CalculationsCalculationsThe arithmetic operations are performed on the numeric data to get The arithmetic operations are performed on the numeric data to get the required results. For example, total marks of each student are the required results. For example, total marks of each student are calculated.calculated.iv) iv) SummarizingSummarizingThe data is processed to represent it in a summarized form. ft means The data is processed to represent it in a summarized form. ft means that the summary of data is prepared for top management. For that the summary of data is prepared for top management. For example, the summary of the data of student is prepared to show the example, the summary of the data of student is prepared to show the percentage of pass and fail student examination etc.percentage of pass and fail student examination etc.


3. 3. OutputOutputAfter completing the processing step, output is After completing the processing step, output is

generated. The main purpose of data processing is to get the generated. The main purpose of data processing is to get the required result. Mostly, the output is stored on the storage required result. Mostly, the output is stored on the storage media for later user. In output step, following activities can media for later user. In output step, following activities can be performed.be performed.i) i) RetrievalRetrieval

Output stored on the storage media can be retrieved Output stored on the storage media can be retrieved at any time. For example, result of students is prepared and at any time. For example, result of students is prepared and stored on the disk. This result can be retrieved when stored on the disk. This result can be retrieved when required for different purposes.required for different purposes.ii) ii) ConversionConversion

The generated output can be converted into different The generated output can be converted into different forms. For example, it can be represented into graphical forms. For example, it can be represented into graphical form.form.iii) iii) CommunicationCommunication

The generated output is sent to different places. For The generated output is sent to different places. For example, weather forecast is prepared and. sent to different example, weather forecast is prepared and. sent to different agencies and newspapers etc. where it is required.agencies and newspapers etc. where it is required.

Types of Data ProcessingTypes of Data Processing

1. 1. Manual Data Processing:Manual Data Processing:This method of data processing This method of data processing

involves human intervention. The manual involves human intervention. The manual process of data entry implies many process of data entry implies many opportunities for errors, such as delays in opportunities for errors, such as delays in data capture, as every single data field has data capture, as every single data field has to be keyed in manually, a high amount of to be keyed in manually, a high amount of operator misprints or typos, high labor operator misprints or typos, high labor costs from the amount of manual labor costs from the amount of manual labor required. Manual processing also implies required. Manual processing also implies higher labor expenses in regards to higher labor expenses in regards to spending for equipment and supplies, rent, spending for equipment and supplies, rent, etc.etc.


EDPEDPEDP (electronic data processing), EDP (electronic data processing),

an infrequently used term for what is today an infrequently used term for what is today usually called "IS" (information services or usually called "IS" (information services or systems) or "MIS" (management information systems) or "MIS" (management information services or systems), is the processing of services or systems), is the processing of data by a computer and its programs in an data by a computer and its programs in an environment involving electronic environment involving electronic communication. EDP evolved from "DP" communication. EDP evolved from "DP" (data processing), a term that was created (data processing), a term that was created when most computing input was physically when most computing input was physically put into the computer in punched card form put into the computer in punched card form or in ATM cards form and output as punched or in ATM cards form and output as punched cards or paper reports.cards or paper reports.


3.Real time processing3.Real time processingIn a real time processing, there is a In a real time processing, there is a

continual input, process and output of data. continual input, process and output of data. Data has to be processed in a small Data has to be processed in a small stipulated time period (real time), stipulated time period (real time), otherwise it will create problems for the otherwise it will create problems for the system. system. For exampleFor example, when a bank customer , when a bank customer withdraws a sum of money from his or her withdraws a sum of money from his or her account it is vital that the transaction be account it is vital that the transaction be processed and the account balance updated processed and the account balance updated as soon as possible, allowing both the bank as soon as possible, allowing both the bank and customer to keep track of funds.and customer to keep track of funds.


4.Batch processing4.Batch processing

In a batch processing group of In a batch processing group of transactions collected over a period of transactions collected over a period of time is collected, entered, processed time is collected, entered, processed and then the batch results are and then the batch results are produced. Batch processing requires produced. Batch processing requires seperate programs for input, process seperate programs for input, process and output. It is an efficient way of and output. It is an efficient way of processing high volume of data. processing high volume of data. For exampleFor example: Payroll system, : Payroll system, Examination system and billing system.Examination system and billing system.

Computer Processing Computer Processing Operations Operations

A computer can perform only the A computer can perform only the following four operations which following four operations which enable computers to carry out the enable computers to carry out the various data processing activities we various data processing activities we have just discussed.have just discussed.(a) (a) Input/Output operationsInput/Output operations

A computer can accept data A computer can accept data (input) from and supply processed (input) from and supply processed data (output) to a wide range of data (output) to a wide range of input/output devices. These devices input/output devices. These devices such as keyboards, display screens, such as keyboards, display screens, and printers make human-machine and printers make human-machine communication possible.communication possible.

Computer Processing Computer Processing OperationsOperations

(b) (b) Calculation and text manipulation OperationsCalculation and text manipulation Operations

Computer circuits perform Computer circuits perform calculations on numbers. They are calculations on numbers. They are also capable of manipulating also capable of manipulating numerics and other symbols used in numerics and other symbols used in text with equal efficiency.text with equal efficiency.


(c) Logic/Comparison Operations(c) Logic/Comparison Operations

A computer also possesses the ability to A computer also possesses the ability to perform logical operations.perform logical operations.

For example, if we compare two items represented For example, if we compare two items represented by the symbols A and B, there are only three by the symbols A and B, there are only three possible outcomes.possible outcomes.A is less than B (A<B); A is equal to B (A=B): or A is A is less than B (A<B); A is equal to B (A=B): or A is greater than Bgreater than B(A>B).(A>B).

A computer can perform such comparisons and A computer can perform such comparisons and the, depending on the result, follow a predetermined the, depending on the result, follow a predetermined path to complete its work. This ability to compare is path to complete its work. This ability to compare is an important property of computersan important property of computers..


(d) Storage and Retrieval Operations(d) Storage and Retrieval Operations

Both data and program instructions Both data and program instructions are stored internally in a computer.are stored internally in a computer.

Once they are stored in the internal Once they are stored in the internal memory, they can be called up quicklymemory, they can be called up quicklyor retrieved, for further use.or retrieved, for further use.