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Prologue to Information Systems

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  1. Chapter 1 Introduction toInformation Systems

  2. Information Concepts (1) • Data vs. Information • Data • Raw facts • Distinct pieces of information, usually formatted in a special way • Information • A collection of facts organized in such a way that they have additional value beyond the value of the facts themselves

  3. Data ‘Discussion’ (1) (1) Distinct pieces of information, usually formatted in a special way. All software is divided into two general categories: data and programs. Programs are collections of instructions for manipulating data. Data can exist in a variety of forms -- as numbers or text on pieces of paper, as bits and bytes stored in electronic memory, or as facts stored in a person's mind. Strictly speaking, data is the plural of datum, a single piece of

  4. information. In practice, however, people use data as both the singular and plural form of the word. (2) The term data is often used to distinguish binary machine-readable information from textual human-readable information. For example, some applications make a distinction between data files (files that contain binary data) and text files (files that contain ASCII data). (3) In database management systems, data files are the files that store the database information, whereas other files, such as index files and data dictionaries, store administrative information, known as metadata.

  5. Homework Is the term “data”generally used in the singular or plural (a) in the textbook, and (b) in the zdwebopedia web site? Q

  6. Terminology • Process • A set of logically related tasks performed to achieve a defined outcome • Process • (n) An executing program. The term is used loosely as a synonym of task. • (v) To perform some useful operations on data.

  7. Terminology • Knowledge • An awareness and understanding of a set of information and how that information can be made useful to support a specific task • Knowledge base • The collection of data, rules, procedures, and relationships that must be followed to achieve value or the proper outcome

  8. Types of Data

  9. Data  Information Data Transformation Information

  10. Characteristics of Valuable Information • Characteristics • Accurate, complete, economical, flexible, reliable, relevant, simple, timely, verifiable, accessible, secure

  11. System • System • A set of elements or components that interact to accomplish goals • A combination of components working together

  12. System ‘Discussion’ (1) Refers to a combination of components working together. For example, a computer system includes both hardware and software. A Windows system is a personal computer running the Windows operating system. A desktop publishing system is a computer running desktop publishing software. (2) Short for computer system. (3) Short for operating system. (4) An organization or methodology. The binary numbering system, for instance, is a way to count using only two digits.

  13. System Elements • Inputs • Processing mechanisms • Outputs

  14. System Example

  15. System Components and Concepts • System boundary • Defines the system and distinguishes it from everything else • System types • Simple vs. complex • Open vs. closed • Stable vs. dynamic • Adaptive vs. nonadaptive • Permanent vs. temporary

  16. System Performance and Standards • Efficiency • A measure of what is produced divided by what is consumed • Effectiveness • A measure of the extent to which a system achieves its goals • System performance standard • A specific objective of the system (next 2 slides)

  17. Figure 1.5a

  18. Figure 1.5b

  19. System Variables and Parameters • System variable • A quantity or item that can be controlled by the decision maker • E.g. the price a company charges for a product • System parameter • A value or quantity that cannot be controlled by the decision maker • E.g., cost of a raw material

  20. Modeling a System • Model • An abstraction or an approximation that is used to represent reality • Types of models • Narrative (aka descriptive) • Physical • Schematic • Mathematical Next slide

  21. Information System (IS) • Definition • A set of interrelated elements or components that collect (input), manipulate (process), and disseminate (output) data and information and provide a feedback mechanism to meet an objective • (IS) Pronounced as separate letters, and short for Information Systems or Information Services. For many companies, IS is the name of the department responsible for computers, networking and data management. Other companies refer to the department as IT (Information Technology) and MIS (Management Information Services).

  22. What is an Information System? • Schematic model of an information system Feedback Input Processing Output

  23. Input, Processing, Output, • Input • The activity of gathering and capturing data • Whatever goes into the computer • Processing • Converting or transforming data into useful outputs • Output • Useful information, usually in the form of documents and/or reports • Anything that comes out of a computer

  24. Input ‘Discussion’ (n) Whatever goes into the computer. Input can take a variety of forms, from commands you enter on a keyboard to data from another computer or device. A device that feeds data into a computer, such as a keyboard or mouse, is called an input device. (v) The act of entering data into a computer

  25. Output ‘Discussion’ (n) Anything that comes out of a computer. Output can be meaningful information or gibberish, and it can appear in a variety of forms -- as binary numbers, as characters, as pictures, and as printed pages. Output devices include display screens, loudspeakers, and printers. (v) To give out. For example, display screens output images, printers output print, and loudspeakers output sounds.

  26. Feedback • Feedback • Output that is used to make changes to input or processing activities • Forecasting • A proactive approach to feedback • Use for estimating future sales or inventory needs

  27. Manual vs. Computerized Systems • Manual systems still widely used • E.g., some investment analysts manual draw charts and trend lines to assist them in making investment decisions • Computerized systems • E.g., the above trends lines can be drawn by computer • Evolution • Many computerized system began as manual systems • E.g., directory assistance (“411”)

  28. Computer-based Information Systems • A CBIS is composed of… • Hardware • Software • Databases • Telecommunications • People • Procedures • Together they are… • Configured to collect, manipulate, store, and process data into information

  29. Technology Infrastructure • Another term for CBIS • Consists of the shared information system (IS) resources that form the foundation of the information system

  30. Parts of a CBIS • Five parts • Hardware • Software • Database • Telecommunications • Networks

  31. Parts of a CBIS • Five parts • Hardware • Software • Database • Telecommunications • Networks

  32. Hardware • Hardware • Computer equipment used to perform input, processing, and output activities • The objects that you can actually touch, like disks, disk drives, display screens, keyboards, printers, boards, and chips.

  33. Hardware ‘Discussion’ Hardware refers to objects that you can actually touch, like disks, disk drives, display screens, keyboards, printers, boards, and chips. In contrast, software is untouchable. Software exists as ideas, concepts, and symbols, but it has no substance. Books provide a useful analogy. The pages and the ink are the hardware, while the words, sentences, paragraphs, and the overall meaning are the software. A computer without software is like a book full of blank pages -- you need software to make the computer useful just as you need words to make a book meaningful.

  34. Parts of a CBIS • Five parts • Hardware • Software • Database • Telecommunications • Networks

  35. Software • Software • Computer programs that govern/determine/control the operation of the computer • Computer instructions or data

  36. Software ‘Discussion’ (1) Software is computer instructions or data. Anything that can be stored electronically is software. The storage devices and display devices are hardware. The terms software and hardware are used as both nouns and adjectives. For example, you can say: "The problem lies in the software," meaning that there is a problem with the program or data, not with the computer itself. You can also say: "It's a software problem.“

  37. Software ‘Discussion’ (2) The distinction between software and hardware is sometimes confusing because they are so integrally linked. Clearly, when you purchase a program, you are buying software. But to buy the software, you need to buy the disk (hardware) on which the software is recorded. Software is often divided into two categories. Systems software includes the operating system and all the utilities that enable the computer to function. Applications software includes programs that do real work for users. For example, word processors, spreadsheets, and database management systems fall under the category of applications software.

  38. Parts of a CBIS • Five parts • Hardware • Software • Database • Telecommunications • Networks

  39. Database • Database • An organized collection of facts and information • A collection of information organized in such a way that a computer program can quickly select desired pieces of data

  40. Database ‘Discussion’ (1) A database is a collection of information organized in such a way that a computer program can quickly select desired pieces of data. You can think of a database as an electronic filing system. Traditional databases are organized by fields, records, and files. A field is a single piece of information; a record is one complete set of fields; and a file is a collection of records. For example, a telephone book is analogous to a file. It contains a list of records, each of which consists of three fields: name, address, and telephone number.

  41. Database ‘Discussion’ (2) An alternative concept in database design is known as Hypertext. In a Hypertext database, any object, whether it be a piece of text, a picture, or a film, can be linked to any other object. Hypertext databases are particularly useful for organizing large amounts of disparate information, but they are not designed for numerical analysis. To access information from a database, you need a database management system (DBMS). This is a collection of programs that enables you to enter, organize, and select data in a database.

  42. Database ‘Discussion’ (3)

  43. Parts of a CBIS • Five parts • Hardware • Software • Database • Telecommunications • Networks

  44. Telecommunications • Telecommunications • The electronic transmission of signals for communications; enables organizations to link computer systems into effective networks • Refers to all types of data transmission, from voice to video

  45. Parts of a CBIS • Five parts • Hardware • Software • Database • Telecommunications • Networks

  46. Networks • Network • Used to connect computers and computer equipment in a building, around the country, across the world, to enable electronic communications • A group of two or more computer systems linked together

  47. Network ‘Discussion’ (1) There are many types of computer networks, including: local-area networks (LANs) : The computers are geographically close together (that is, in the same building). wide-area networks (WANs) : The computers are farther apart and are connected by telephone lines or radio waves.

  48. Network ‘Discussion’ (2) In addition to these types, the following characteristics are also used to categorize different types of networks: topology : The geometric arrangement of a computer system. Common topologies include a bus, star, and ring. protocol : The protocol defines a common set of rules and signals that computers on the network use to communicate. One of the most popular protocols for LANs is called Ethernet. Another popular LAN protocol for PCs is the IBM token-ring network . architecture : Networks can be broadly classified as using either a peer-to-peer or client/server architecture.

  49. Network ‘Discussion’ (3) Computers on a network are sometimes called nodes. Computers and devices that allocate resources for a network are called servers.