Information Systems Information systems are systems that provide information to users
ContentsJust press enter to go to the next page or click on the hyperlink to go to a particular topic
8.1 Hardware • 8.2 Software (word processors, spreadsheets, databases) • 8.3 Data (Data structures, Data preparation, validation and verification, data manipulation) • 8.4 Applications (Maintaining data of an organisation, using a database system, on-line database systems, computer retrieval systems) • 8.5 People (providers of information services, users of information, abuse of information systems)
Outcomes By the end of this unit you should be able to: • Understand the function and effects of information systems • Outline the hardware used in information systems • Use the basic features of a word processor, spreadsheet and database • Describe the organisation of data in an information system
8.1 Hardware • Hardware is the parts of the information system (I.e. the parts of the computer) which can be touched.
Peripheral devices (hardware) • A peripheral devices is any input or output device connected to a computer. • Input devices are components such as a mouse, keyboard, scanner and modem • Output devices are components such as monitors, printers and modems
Storage (Hardware) • Storage is crucial for any information system. Without storage we could not save any of our work and this would make an information system next to useless. • There are a range of storage devices including hard drives, optical disks (including CD and DVD), zip drives, floppy drives, magnetic tape
Processing (hardware) • The processor is the part of the computer which actually controls the computer and manages the flow of data. This refers to the CPU (central processing system)
8.2 Software • Software refers to the programs run on the computer. • There are two types of software: system software and application software. • System software deals with the management of the processes of running the computer such as Windows and MacOS • Application software is used when a specific task is done on the computer such as a word processor, spreadsheet or game program.
Word processors (software) • Word processors are application programs which allow text editing. • Many word processors allow users to manipulate graphics and do a number of other tasks as well as writing documents.
Spreadsheets (software) • A spreadsheet is an application program which allows numerical calculations and the sorting and displaying of numerical data. • A spreadsheet is divided into rows and columns. • Columns run vertically (up and down) just like the Greek columns. • Rows run across
Databases (software) • Databases are application programs which are used to collect, store and process data into information.
8.3 Data • Data is the raw unprocessed facts. • Data becomes information after it is sorted and organised.
Data Structures (data) • Ways of organising data is called data structures • Some ways of organising data is arrays, files and records. • Spreadsheets organise data into rows and columns. One block of information (at the intersection of a row and column is called a cell. Spreadsheets have the same organisation as a two dimensional array. • Databases organise information into files, records, fields and entries (flat file database structure)
Arrays (a data structure) • Array: an array is an arrangement of data into a table like structure similar to a spreadsheet. This is a two dimensional array. • Look at the table below. In cell A3 is d. In A7 is John. Notice with a cell reference the row is said first “A” followed by the column “3” thus we end up with A3. • Very importantly an array must have the same data type. Notice this is all text.
Database (data structures) • A database will be saved as a file. • Inside that file will be a record which is composed of several fields and each field will contain an entry. • For example in the school database there would be a file with all of the students names. If we chose an individual student to look up we look up the record on that student. The student’s name is one field. The address is another field.
Hierarchical Structure (data structure) This chart shows a data structure which has a hierarchy or in other words levels. This type of chart is called a hierarchy chart. Level 0 Level 1 Level 2
Methods of Data Access (data structures) • A file can be accessed either directly because we have an address such as in our earlier array or sequentially. • A sequential file is probably stored in some kind of ascending or descending order but the computer must look at every bit of information in the order in which it is stored until the correct entry is located. Sequential access is very slow. • A direct access file is located very quickly because the computer uses a form of index and addressing system to locate the correct entry.
Data preparation • Data preparation involves the preparation of data for use in a database. • This involves its collection, organising, sorting and data entry into the computer
Validation • Data validation takes place when the data is entered into the computer. • It is normally built into the software and will do a type check or range check of data try to ensure the data is correct. • For example if I entered my name by mistake where it asked for data of birth, data validation tells the program that it was supposed to be numbers but I have entered text. Likewise if it was expecting 4 numbers but I entered in 7 then the program would know that I have made a mistake.
Verification • Verification of data is part of the maintenance of a database. It is to check that the data is still accurate. • Have any of the details in the database changed? • For example: Has a persons address or phone number changed?
Data manipulation • Data manipulation involves the sorting or statistical manipulation of that data to derive other information. • Data manipulation is one of the key uses for a database or spreadsheet. • When large databases do this commercially and mine the data for other information held within it this is referred to as “data mining” and is worth a lot of money.
8.4 Applications • This involves how databases, spreadsheets and other software applications are used in the real world.
Maintaining data of an Organisation • This involves the entire process of entering new data and making sure that verification of the data in the company system is accurate. • An organisation will use databases to store personnel information and payroll information. • Data verification is crucial to the successful use of the information system
Using a database system • Database systems are very useful for companies. • Orders, invoicing, human resources and payroll are probably the main uses that businesses make of information systems. • An order form will give the details of goods that a company has ordered to buy. • An invoice will be generated when the goods are delivered. • Inventory management is another use for an information system. This will keep track of all the property or goods a company has in stock.
On-line Database Systems • On-line database systems are used for EFTPOS (electronic funds transfer at point of sale) transactions, web transactions, e-bank transactions, airline bookings, theatre bookings, saving data from web forms and a variety of other online uses. • Online database management is a growth industry with a large untapped potential
Computer Retrieval Systems • This refers to retrieving data from an online database. • So much information is now stored on the web that it is hard to imagine not using an online retrieval system. • Computer retrieval systems are used by libraries, schools, shops, banks, credit reference and finance companies, doctors and hospitals • In fact any search on the web relies on a computer retrieval system
8.5 People • People are referred to as users or participants and are a critical element of any information system • People design, construct, maintain and operate information systems. • Unfortunately as information systems become more reliable the number of people required is reducing.
Providers of Information Services The people directly involved in an information system includes: • Systems analysts: design information systems • System managers: manage the operation of the system. • Computer programmers: create the software the information system uses. • Computer operators: Look after the basic requirements of a computer system. (This is one category of It job which is quickly disappearing as users become more IT literate) • Data entry operators: Enter the data into the system
Users of Information • Users are those affected by the system. There are three types of users: direct users, indirect users and intermediary users. • Direct users: Direct users are those who will directly interact with the system. They will either enter or retrieve information but either way they will physically be using the system themselves. • Indirect users: They will not directly use the system. When we buy groceries or hire a video the customer does not enter the information into the system. • Intermediary Users: Intermediary user is a direct user who interacts with the information system on behalf of the indirect users. Looking at the video store example again the shop assistant who is the direct user acts as an intermediary user on behalf of the customer who is an indirect user.
Abuse of Information Systems • Information needs to be safeguarded. • People will try to “hack” (break into) systems and steal information. • This activity is not only illegal but is also criminal. • The information stolen can be sold and then money may be stolen out of people’s accounts, credit card details can be used and even people’s identities are stolen (people will pretend to be other people). • Firewalls and a variety of other antihacking tools are used in an effort to stop hacking.
REVIEW EXERCISE 8 • 1. Copy and complete the following sentences. • (a)______________ systems are systems that provide information to users. information
Review exercise 8 • (b) A peripheral device is any input or output device that connects to a computer’s_______ CPU
Review exercise 8 (c)A spreadsheet uses a rectangular grid made up of rows and ____________ columns
Review exercise 8 database (d) A ___________ is an organized collection of data.
Review exercise 8 (e) A file is a block of data divided into a set of related _________. records
Review exercise 8 • ( f ) Sequential files arrange their records in ascending or descending order according to a __________. Key field
Review exercise 8 Sorting (g) _________ is the process of arranging data in a particular order.
Review exercise 8 (h) Databases are accessed by a _______. DBMS
Review exercise 8 EFTPOS ( i ) ___________ is a way of paying for goods and services by transferring funds directly from your bank account.
Review exercise 8 People ( j) _________ are involved in every aspect of an information system.
Review exercise 8 2. What is a terminal? An input and output device, usually a keyboard and monitor, that communicates with another computer.
Review exercise 8 3. What storage medium is growing in popularity for storing data in information system? CDs that are increasingly popular for storing data.
Review exercise 8 5. List three common types of software used in information system. Common types of software are word processor, spreadsheets and databases.
Review exercise 8 6. What advantages do word processor have over other methods of writing? . ease of editing text – mistakes can be corrected and text moved before printing; . variety of fonts – different typefaces each with a particular size, style and weight; . ease of storage – text can be stored on a disk and retrieved as required.
Assignment 8 1. What is the purpose of the library computer system?