Standard Grade Computing

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					Standard Grade Computing
  Commercial Data Processing
Commercial Data Processing deals with how LARGE
companies and organisations use computers in their
Examples of large companies and organisations:
•      supermarkets (ASDA, Tesco, Morrisons)
•      chain stores (Currys, Comet, Argos)
•      banks (Royal Bank of Scotland, Clydesdale, Abbey)
•      airlines (British Airways, Ryanair, Qantas)
•      organisations (police, Inland Revenue, DVLA)
           Mainframe Computer
Key facts about a mainframe:
A large computer system that can process huge amounts of
data accurately and at very high speeds

Has hundreds of dumb terminals attached to it

Has a very large amount of RAM (many Gigabytes)

Has more than one processor

Has a huge backing storage capacity (Gigabytes or Terabytes)
              Need for CDP (1)
Volume of Documents – large companies and organisations
need to process a huge amount of data every day

Speed of processing – computers are ideal for accurate
processing of data at very high speeds. Human beings process
data slowly in comparison

Repetitive tasks – computers are great at performing the
same task over and over again without making mistakes.
Humans get tired and make mistakes when they do the same
task continuously
             Need for CDP (2)
Speed of Access – the data stored on a computer can be
found and accessed very quickly. Human beings
searching for data in paper based systems (eg filing
cabinets) takes much longer
Management Information – computers process data and
turn it into information. Managers can use the information to
run their businesses more effectively

Example: A supermarket manager might want to know how
many tins of Heinz beans were sold in a week and how
much money (£££) the company made from selling beans
       Data Processing Cycle (1)
The data processing cycle is the order that data is processed in. The
data processing cycle is made up of 4 stages:

1. Data collection and preparation
2. Data input
3. Data processing and storage
4. Data output
       Data Processing Cycle (2)
What is data?
Data are the numbers, symbols and characters that can be
processed by a computer. Data on its own has no meaning
to human beings.
Examples of data: 01001110      .-.-.--.-.-.---…--.-. 2532302822

 What is information?

 Information is data that has been processed by a computer
 into a human readable format.

Examples of information: £25   12 January 2006     250 Centigrade
   Data Processing Cycle (3)
Information (for people) = data (for computers) + meaning

   This piece of data:

                         603 30 9


                     30 March 1969

    when processed into information by a computer
               Data Collection and
 Data can be collected in many different ways. If data is written
 down or printed on a piece of paper, that piece of paper is called a
 source document.

An order form for a catalogue is an
example of a source document.
                   Data Input (1)
Data needs to be input into the computer BEFORE it can be
processed. Inputting data directly into a computer means that
fewer mistakes will be made.
Here are some ways of inputting data into a computer:
 •      bar codes
 •      mark sense cards
 •      magnetic stripes
 •      smart cards
 •      magnetic ink character recognition (MICR)
 •      optical character recognition (OCR)
                    Data Input (2)
 Bar Codes
                        5   012345   678956

Can be found on books, groceries, newspapers etc
Made up of black and white vertical bars that hold coded
Coded information is read by reflected laser light
The 4 pieces of coded information        country of origin
on a bar code are:                       manufacturer
                                         check digit
                      Data Input (3)
Mark sense cards                           Ayrshire General
                              Name: Joe Bloggs
Marks are made on cards       WARD: 2a
that can be read by special
                                      ] TO CHOOSE               DIET
card reading equipment        EXTEND THE BAR TO THE BRACKET

                                      ] 1 Scotch Broth
                                      ] 2 Chicken Soup
                                      ] ……………………………………………………….
                                         3 Orange Juice

                                      ] 4 Poached Haddock in Milk
Mark cards can be used in             ] 5 Chicken Curry
                                      ] ……………………………………………………….
                                         6 Ham Salad
multiple choice exams and             ] 7 Jelly and Ice Cream
to choose your food when              ] 8 Trifle
                                      ] 9 Apple Pie
you are in hospital
                     Data Input (4)
Magnetic stripes

A magnetic stripe is a narrow band
                                     Signature   J Bloggs
of magnetic material on which data
is held
Can be seen on the back of credit
cards, bank card and train tickets

Stores information like sort codes
and account numbers
                     Data Input (5)
Smart Cards
                                         Second Direct
                                                                         Credit Card
These cards can be used as bank
cards, credit cards, store cards and   675940 00001234567
identity cards                         VALID
                                       FROM            END
                                         Miss Jane Bloggs
They have a microchip that can
hold and process information
They can store personal
information and hold digital cash
More secure than magnetic stripe
cards because they are difficult to
                    Data Input (6)
Magnetic Ink Character Recognition

Is the process where characters
are printed on forms in
magnetic ink
People and computers can read
the characters

When a cheque is paid into a bank a magnetic ink
character reader is used to input the information
into a computer
                      Data Input (7)
 Optical Character Recognition (OCR)

A device called an optical           UK GAS                                                          Customer Ref. No.
                                      MR J RAE                                                         216 024 4567
character reader is able to
recognise letters and numbers    Date             Meter Reading
                                                  Present       Previous
                                                                             Gas Supplied
                                                                            100’s cu ft    Therms

(eg ABC or 1234) and read       31 JAN     1878
                                STANDING CHARGE
                                                                1502           376        397.432              182.42

them directly into a computer                                  CREDIT TARIFF                             £     191.82

                                   BANK PAY                      Customer Ref. No.                       Amount Due
                                                                                          Customer Acc. No.

An OCR system CAN’T read
                                                                 216 024 4567               118 3467               £ 191.82
                                Cashier’s Stamp and initials
letters or numbers that have                                    Signature
been printed badly
                                                                                                     Total £
                                        Please do not write or mark below this line or fold this counterfoil

                                191825          2160244567                      00          2160244567 00191825
                     Data Input (8)
Validation is a pre-input check on data to make sure that it is
sensible and accurate

Examples:       Check Digit     Length Check       Range Check

Verification involves using two different human operators to enter
the same data. The computer compares both sets of data that have
been entered and, if it finds a mistake, both sets of data must be
entered again
                      Data Input (9)
A check digit is an extra digit that is calculated from an original
number and is then put on the end of the number.

Example : let’s make up a check digit for the number         2954

We add all the digits together      2 + 9 + 5 + 4 = 20
To make the total divide exactly by three, we MUST add an extra
digit (in this case a 1) at the end of the number to make the total 21.
This is because 21 divides exactly by three
So the check digit is a     1

Adding the check digit to the original number gives          29541
                  Data Input (10)
Length Check
This involves checking the number of characters (numbers,
letters and spaces) entered into a computer. If too many or too
few characters are entered then an error message will be
Example A date needs to be entered into the computer in the
format ddmmyyyy – which is 8 characters long

Only dates with exactly 8 characters (eg 30031969) are valid

If you made a mistake and typed in 303031969
the computer would not accept the data and give an error
                    Data Input (11)
Range Check
A range check can be made on numeric data like ages, money and
test marks to check that the numbers are sensible and in the
correct range
A valid age range for secondary
school pupils should be between
11 and 18
In Higher Computing a valid
range of marks for a test is
between 0 and 20
    Data Processing and Storage (1)
File – is an organised collection of structured data on the same topic.
The units that make up a file are records.
Record – is an organised collection of structured data on a person
or thing (entity). A record is like a single card in a card index.
Field – a single piece of information that appears on a record.

                    Employee No        001

                    Job Title      Systems Analyst
                    Name           Ian Wright                file
                    Salary         £40,000
    Data Processing and Storage (2)
    Backup – this is a copy of your original data file
    •         A backup is needed in case the original data file is
              accidentally or deliberately lost
    •         There should be more than one backup copy of a
•       Backup copies
        should be
        stored in a
        fireproof safe
        for extra security
                             Original file stored   Backup copy stored on a
                               on hard disk           separate hard disk
         Data Processing and Storage (3)
         Update – this means adding new data or making changes
         to old data that is already stored in a data file
         Example: Ian Wright gets a salary increase from £40,000
         per year to £50,000 per year. This means that his record in
         the employee data file needs to be updated:

Employee No              001                      Employee No         001

Job Title         Systems Analyst                 Job Title       Systems Analyst

Name              Ian Wright                      Name            Ian Wright

Salary                                            Salary           £50,000

            old record                                        new record
   Data Processing and Storage (4)
File access methods

Sequential access is used to store data files on magnetic tape

The records in the data file are stored one after the other

To access a particular record the computer would have to go
through all the records in sequence from the beginning until it was
     Employee No   001               Employee No   002          Employee No 003               Employee No       004
     Job Title     Systems Analyst   Job Title     Programmer   Job Title  Data Input Clerk   Job Title Computer Operator
     Name          Ian Wright        Name          Laura Wood   Name       Cameron Rae        Name      Helen Black
     Salary        £40,000           Salary        £35,000      Salary     £15,000            Salary     £27,000

                                               Magnetic tape
   Direction of Search
 Data Processing and Storage (5)
Direct/Random access data files stored for direct access can be
read directly without having to work through all the records
from the beginning

Magnetic disks and optical disks are two
examples of direct access media
Interactive processing is when data is processed or updated as
a transaction is entered and any queries are replied to at once

         Examples : booking holidays and
         automated teller machines (ATM’s)
    Data Processing and Storage (6)
  Multi-user database – this is a database on a network that can
  be accessed by many users at the same time
  To allow multi-user access the database file must be stored
  centrally on either a mainframe computer or a file server
Example – when lots of people can access their bank’s account
database at the same time

                                                        ATM in Glasgow
ATM in Kilmarnock

                         Bank account details stored
                         in a database on a mainframe    ATM in
            ATM in Ayr
                         computer in Edinburgh           Aberdeen
                    Data Output
Output to Paper – print-outs are created for staff and
customers. High speed printers are used to create the print-outs
             Examples – bank account statements,
             electricity and gas bills and wage slips

Output to Screen – screen output is used to allow the computer
to communicate with the operator

Output to file – output can be saved as a new file for
processing later. The new file would be stored on tape or disk.
      Social Implications (1)
Job losses because computers have replaced people doing
traditional jobs (eg typists)

Retraining – workers that are left need to be trained how to
operate, program and maintain the computer system(s)

Effects on business – companies will enjoy higher
productivity and higher profits
         Social Implications (2)
Job types and careers:

Programmer – designs, writes and tests the programs that
process all the data
Engineer – maintains the computer system(s) and repairs
them if they break down

Network manager – is the person in overall charge of the

Systems Analyst – looks at manual or legacy systems and
decides on the hardware and software to be used by a
           Social Implications (3)
Computer crime:           Hacking involves
Computer viruses          illegally breaking
are rogue programs        into a computer
that replicate            system. If data is
themselves and can        damaged it is called
destroy and corrupt       cracking

Computer Fraud          Computer Misuse Act
normally involves       is a law that tries to
stealing money          prevent these crimes
electronically          from happening
       Technical Implications (1)
E-commerce – is the process of buying and selling goods and
services on the Internet
Examples: (insurance)
      Technical Implications (2)
On-line shopping – is another name for e-commerce

Involves visiting a web site and using a shopping basket to
store the items you have selected and want to buy
When the purchase is complete the web site will send an e-mail
to confirm the order has been placed
How do you pay for on-line shopping?

Credit cards (Visa and Mastercard)
Debit cards (Switch and Delta)
      Technical Implications (3)
Advantages of on-line shopping:
For companies - selling on the Internet is cheaper than selling
on the high street
Customers can shop 24 hours a day from the comfort of their
own home
Disadvantages of on-line shopping:
Fraud can take place when a credit or debit card is stolen and
the number on it is used to buy something on the net – this type
of activity is called card not present fraud
A customer may not be at home when the goods are delivered
       Technical Implications (4)
On-line banking – is the process of accessing your bank
account and carrying out transactions on the Internet (eg pay
bills and move money)

Involves logging into a secure web site (small padlock should
be at the bottom of the screen)

Customer must enter a User ID and Password to enter the site

Advantage – on-line banks         Disdvantage – the service can
DO NOT need to have               be impersonal (ie no face to
branches in the High Street       face contact with a person)
which saves the bank money
          Technical Implications (5)
Electronic Funds Transfer (EFT)
This is where you pay for goods and services without using

When you buy something, the money that you owe the shop
is transferred electronically from your bank account into the
shops bank account

 Your banks computer                    The shops computer

You need to have a bank card that supports this type of
      Technical Implications (6)
Point of Sale (POS)
POS is the name given to to a computerised system that
collects data automatically from the checkout, or point of sale,
as the customer buys goods
At the checkout a scanner reads the unique bar code on the item
that has been sold

The product code for the item is then sent to the till which is
connected to a computer that recognises all the product codes
for items in the shop
The till, using information from the computer, can then display
the name and price of the product
      Economic Implications (1)
Initial costs are the costs (amounts of money) involved in
buying the equipment needed to computerise a large business

Hardware – computers, printers, bar code readers

Software – operating systems, application packages,
bespoke software
        Economic Implications (2)
Running costs are the costs (amounts of money) involved in
keeping the system operational day in and day out


Toner and ink
            Security and Privacy
              Implications (1)
Accuracy of information and privacy
Large companies hold data about employees and customers
Companies must register with the Information Commissioner
who is responsible for the Data Protection Act
A principal of the Data Protection Act is that information must
be accurate and up to date

Information held in a computer data file must be kept private.
Information about how much someone earns or how much
credit they have been given SHOULD NOT be shown to
anyone else
            Security and Privacy
              Implications (2)
Physical security
Computers and data files cab be kept secure by:
Locking doors – a swipe card and/or pin number may have to
be used to enter the computer room

Locking keyboards – some keyboards can be locked so that
they can’t be used by unauthorised people
              Security and Privacy
                Implications (3)
  Software security
  Passwords – a password should not appear on the screen
  (eg ******** ) and should be changed regularly

  Encryption – this means to turn information into a code to
  prevent it from being read by unauthorised users
how are you                                          krz duh brx
          Security and Privacy
            Implications (4)
Sale of customer lists
Some companies sell their lists of customer names and
addresses to other companies to make money
This is why we get so much junk mail nowadays

NOTE – you have the right to stop your name being used in
this way
                 Advantages (1)
Comparison with a manual system

A computerised CDP system has the following advantages:

•     accuracy – less likely to make mistakes/processes
      data more accurately than people
•     speed – data is processed more quickly using

•     volume of documents – computers can handle a
      larger number of documents than people
                      Advantages (2)
Single entry multiple use
This means data is entered once into the computer and can
then be accessed for a number of different uses within an
Example – a new salesman gets a job for a big company and his
details are entered into the computer. Different departments can
now access and use the data.
                                               sales dept

                                                   wages dept
   Employee details
                           Questions (1)
1   Give four types of companies and two organisations that use CDP.

2   Give four facts that you know about a mainframe computer.

3   Briefly describe four reasons why companies use computers to process their data.

4   List the four stages that make up the data processing cycle.

5   (a)   What is the difference between data and information?

    (b)   Give an example to support your answer.

6   Turn the following dates into data codes

    31 March 1931
    25 December 1999
    15 October 1976
                               Questions (2)
7    (a) What is a bar code?

     (b) What four pieces of coded information can be found from a bar code?
8    (a) What is a mark sense card?

     (b) What three items did Joe Bloggs choose to eat when in hospital?
9    What is a magnetic stripe?

10   What is a smart card?

11   What is meant by the term Magnetic Ink Character Recognition?

12   What is meant by the term Optical Character Recognition?

13   What is meant by the term validation?
                                Questions (3)
14   Give three types of validation that can be performed on data

15   What is meant by the term verification?

16   What is a check digit?

17   What is a length check?

18   What is a range check?

19   What is:    (a)           a file     (b)         a record    (c)     a field

20   Why is it a good idea to keep a backup of your original data file?
                              Questions (4)
21   What does the term update mean?

22   What is meant by the term sequential access?

23   Give one disadvantage of sequential access

24   What is meant by the term direct access?

25   Give one advantage that direct access has over sequential access.

26   What is meant by the term interactive processing?

27   What is a multi-user database?
                              Questions (5)
28   Briefly describe three ways in which information can be output from a computer.

29   Briefly describe the following job types and careers:
                 Network manager
                 Systems analyst
30   Give three examples of computer crime.

31   Name the law that tries to prevent computer crimes from happening.

32   What is e-commerce?

33   Explain what happens when you go on-line shopping?

34   Give one advantage and one disadvantage of on-line shopping.
                                Questions (6)
35   What is on-line banking?

36   Give one advantage and one disadvantage of on-line banking

37   Describe how Electronic Funds Transfer works.

38   What is meant by the term Point Of Sale?

39   Identify some of the initial costs involved in computerising a large business.

40   Identify some of the running costs involved in computerising a large business.

41   Give two types of physical security used to keep computers and data files safe.
                              Questions (7)
42   Give two types of software security used to keep computers and data files safe.

43   What is meant by the term sale of customer lists?

44   Give three advantages that a computerised CDP system has over a manual system.

45   What is meant by the term single entry multiple use?

                                  THE END (phew!!!)