INDEX LESSON 1: INTRODUCTION TO DATA PROCESSING …

1 INDEX LESSON 1: INTRODUCTION TO data PROCESSING LESSON 2: CONCEPTS OF FILES LESSON 3: data STORAGE LESSON 4: INTRODUCTION TO COBOL LESSON 5: COBOL VERBS-I LESSON 6: COBOL VERBS-II LESSON 7: ADVANCED COBOL VERBS LESSON 8: COBOL CLAUSES LESSON 9: TABLE HANDLING- I LESSON 10: TABLE HANDLING- II LESSON 11: STRUCTURED PROGRAMMINIG LESSON 12: FILES IN COBOL LESSON 13: SORTING AND MERGING OF FILES LESSON 14: CHARACTER HANDLING Author s Name: Sh. Varun Kumar Vetter s Name: Prof. Dharminder Kumar LESSON 1 INTRODUCTION TO data PROCESSING Objectives At the conclusion of this LESSON you should be able to know: data PROCESSING data & Information Types of data Input, PROCESSING and Output Architecture of Computer System Input Devices Output Devices INTRODUCTION data PROCESSING is any computer process that converts data into information.

2 The PROCESSING is usually assumed to be automated and running on a mainframe, minicomputer, microcomputer, or personal computer. Because data are most 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. To better market their profession, a computer programmer or a systems analyst that might once have referred, such as during the 1970s, to the computer systems that they produce as data - PROCESSING systems more often than not nowadays refers to the computer systems that they produce by some other term that includes the word information, such as information systems, information technology systems, or management information systems.

3 In the context of data PROCESSING , data are defined as numbers or characters that represent measurements from the real world. A single 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. 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 the converting of data back into information. The distinction is that conversion doesn't require a question (query) to be answered.

4 For example, information in the form of a string of characters forming a sentence in English is converted or encoded from a keyboard's key-presses as represented by hardware-oriented integer codes into ASCII integer codes after which it may be more easily processed by a computer not as merely raw, amorphous integer data , but as a meaningful character in a natural language's set of graphemes and finally converted or decoded to be displayed as characters, represented by a font on the computer display. In that example we can see the stage-by-stage conversion of the presence of and then absence of electrical conductivity in the key-press and subsequent release at the keyboard from raw substantially-meaningless integer hardware-oriented data to evermore-meaningful information as the PROCESSING proceeds toward the human being. A more conventional example of the established practice of using the term data PROCESSING is that a business has collected numerous data concerning an aspect of its operations and that this multitude of data must be presented in meaningful, easy-to-access presentations for the managers who must then use that information to increase revenue or to decrease cost.

5 That conversion and presentation of data as information is typically performed by a data - PROCESSING application. When the domain from which the data are harvested is a science or an engineering, data PROCESSING and information systems are considered too broad of terms and the more specialized term data analysis is typically used, focusing on the highly-specialized and highly-accurate algorithmic derivations and statistical calculations that are less often observed in the typical general business environment. This divergence of culture is exhibited in the typical numerical representations used in data PROCESSING versus numerical; data PROCESSING 's measurements are typically represented by integers or by fixed-point or binary-coded decimal representations of real numbers whereas the majority of data analysis 's measurements are often represented by floating-point representation of real numbers.

6 Practically all naturally occurring processes can be viewed as examples of data PROCESSING systems where "real world" information in the form of pressure, light, etc. are converted by human observers into electrical signals in the nervous system as the senses we recognise as touch, sound, and vision. Even the interaction of non-living systems may be viewed in this way as rudimentary information PROCESSING systems. Conventional usage of the terms data PROCESSING and information systems restricts their use to refer to the algorithmic derivations, logical deductions, and statistical calculations that recur perennially in general business environments, rather than in the more expansive sense of all conversions of real-world measurements into real-world information in, say, an organic biological system or even a scientific or engineering system.

7 data 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: operational or transactional data such as, sales, cost, inventory, payroll, and accounting non-operational data , such as industry sales, forecast data , and macro economic data meta data - data about the data itself, such as logical database design or data dictionary definitions Information The patterns, associations, or relationships among all this data can provide information. 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 of; for example, weight, sex, ethnicity, job grade, and consider their different attributes.

8 These variables can be described as categorical or quantitative. The table summarizes data types and their associated measurement level, plus some examples. It is important to appreciate that appropriate methods for summary and display depend on the type of data being used. This is also true for ensuring the appropriate statistical test is employed. Type of data Level of measurement Examples Nominal (no inherent order in categories) Eye color, ethnicity, diagnosis Ordinal (categories have inherent order) Job grade, age groups categorical Binary Gender (2 categories special case of above) Discrete (usually whole numbers) Size of household (ratio) Quantitative (Interval/Ratio) (NB units of measurement used) 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) Table Types of data Input, PROCESSING and output Whenever a computer is used it must work its way through three basic stages before any task can be completed.

9 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 which 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 in to the program, garbage is what will come out of the computer.

10 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 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'.