Information Systems

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Information Systems

• Information systems are systems that provide
  information to users

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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)

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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

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8.1 Hardware

• Hardware is the parts of the information system
  (I.e. the parts of the computer) which can be
  touched.

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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

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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

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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)

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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.

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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.

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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

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Databases (software)

• Databases are application programs which are used
  to collect, store and process data into
  information.

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8.3 Data

• Data is the raw unprocessed facts.
• Data becomes information after it is sorted and
  organised.

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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)

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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.

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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 students name is
  one field. The address is another field.

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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
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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.

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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

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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.

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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?

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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.

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8.4 Applications

• This involves how databases, spreadsheets and
  other software applications are used in the real
  world.

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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

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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.

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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

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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

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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.

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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

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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.

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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 peoples accounts, credit
  card details can be used and even peoples
  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.

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REVIEW EXERCISE 8

• 1. Copy and complete the following sentences.
• (a)______________ systems are systems that
  provide information to users.

information
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Review exercise 8

• (b) A peripheral device is any input or output
  device that connects to a computers_______

CPU
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Review exercise 8

• (c)A spreadsheet uses a rectangular grid made up
  of rows and ____________

columns
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Review exercise 8
database

• (d) A ___________ is an organized collection of
  data.

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Review exercise 8

• (e) A file is a block of data divided into a set
  of related _________.

records
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Review exercise 8

• ( f ) Sequential files arrange their records in
  ascending or descending order according to a
  __________.

Key field
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Review exercise 8
Sorting

• (g) _________ is the process of arranging data in
  a particular order.

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Review exercise 8

• (h) Databases are accessed by a _______.

DBMS
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Review exercise 8
EFTPOS

• ( i ) ___________ is a way of paying for goods
  and services by transferring funds directly from
  your bank account.

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Review exercise 8
People

• ( j) _________ are involved in every aspect of an
  information system.

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Review exercise 8

• 2. What is a terminal?
• An input and output device, usually a
  keyboard and monitor, that communicates with
  another computer.

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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.
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Review exercise 8

• 5. List three common types of software used in
  information system.

Common types of software are word processor,
spreadsheets and databases.
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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.
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Assignment 8

• 1. What is the purpose of the library computer
  system?

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