1. A customer uses a bank card to purchase a product at a supermarket checkout. The
checkout operator uses a number of devices to input data about the customer and the
product.
Identify these input devices and for each one describe a different item of data that
will be input.
matched pairs:
Chip reader
Bank/credit card account information/supermarket code
Bar code reader
Information from a product label/product identity number
Electronic scales
Weight of an item
Touch screen
Identification of product
Number pad
Bar code number when bar code reader cannot read bar code/the number of items
Magnetic stripe reader
Information about the customer
2. (a) Describe batch processing of data, using the processing of bank cheques
as an example.
(a)
Data/cheques are collected together
during the course of the day
Data/cheques are then processed all at once
Data/cheques are processed overnight
Dank accounts updated following morning
No human intervention
(b) Explain why the booking of airline tickets using batch processing would not be a good
idea.
(b)
It might lead to double booking
Customer would not be sure booking has been successful
Would take a long time to receive confirmation/ticket
Processing would take a long time…
… would cost company money
3. Describe the drawbacks of using a command line interface (CLI) operating system.
A CLI only allows you to type in commands
With CLI syntax has to be precise
Commands difficult to edit once entered
Have to learn a lot of commands exactly/have to be familiar with the commands
4. Optical discs and magnetic tapes are both used to store computer data.
Give uses of optical discs and for each use give a reason why they are preferred to
magnetic tapes.
matched pairs:
Companies selling their software/games
Cheap method of production/quick to access data
Making personal backups/transferring data (from one computer to another)
Cheap to buy/quicker to retrieve data/expensive to buy tape drives
Downloading/Copying media such as films/music
Faster/Easier to access individual scenes/tracks/ better or higher quality
5. Iqbal wants to test the new computerised payroll system he would like to introduce to his
company. No company worker is paid less than $100 and no worker is paid more than
$500. Explain what is meant by the following three types of test data using examples of the wages paid to workers.
Normal
Abnormal
Extreme
Normal data – data within a (given) range/appropriate for that data type
Example – any wage between $100 and $500
Abnormal data – data outside the range/of the wrong data type
Example – any wage less than $100 or greater than $500 or text example
Extreme data – data on the boundaries of the range
Example – $100 or $500
6. The head teacher of a school is concerned that students may be hacking into the exam
scores database to change their marks.
Other than passwords, describe ICT methods that could be used to prevent this from
happening.
Biometric methods – unique so only authorized users will have access
Encryption makes it difficult for unauthorised users to read data
Firewall – makes it difficult for unauthorised computers to access the system
Disconnect records computer from network – limit access physically
Access levels – only users with appropriate permissions can access data
7. Discuss the use of blogs and social networking sites as means of communication.
Blog is public/anyone can see it
Blog is online diary/personal opinions
Viewers can only add comments on blogs/authors can reply to comments
Only author can edit blog
Social networking sites might only be available to friends of user
Social networking site enable users to send messages to small group of ‘friends’ to arrange
meetings
Friends can respond more quickly to messages within the group to confirm availability
Easier to share photographs with others
Social networking sites can lead to seclusion from society
Social networking sites can lead to cyber bullying
8. Explain why computer systems have both backing storage and RAM.
If computer is switched off work in RAM goes but backing storage stores data for future use
More likely that data is accidentally deleted in RAM
RAM is more expensive than backing storage per unit of memory
RAM is bulkier than backing storage per unit of memory
RAM provides faster access than backing storage
Software package may be so large that it is physically impossible for RAM to store it.
Data may need to be transferred from one computer to another and can’t do that with RAM
9. (a) Doctors often use expert systems to help them to diagnose illnesses.
Name components of a typical expert system.
User interface
Rules base
Knowledge base
Inference engine
(b) Name other applications which involve the use of expert systems.
Engine car fault diagnosis
Prospecting
Tax
Careers
Chess games
Animal/plant classification
10. Name and describe validation checks which could be carried out on a 16-digit credit
card number when it is typed into a computer.
pairs:
Length check
Checks there are exactly 16 characters
Invalid character/type check
Checks all characters entered are digits
Check digit
Single digit calculated from other digits appended to these, computer carries out fresh calculation
on digit and compares answer with original check digit.
Existency check
Is the card number on the database
11. Describe how the following health problems can arise due to the use of computers. Give a
different cause for each.
RSI in the wrists
RSI in the fingers
Headaches
Back pain
RSI (Repetitive strain injuries) in the wrists – caused by repetitive typing/prolonged gripping of mouse
RSI in the fingers – caused by repetitive clicking of mouse
Headaches – staring at the screen for too long
Back pain – sitting in the same position for long periods
12. A bank is looking into a variety of security measures to protect its customers’ data.
Describe types of authentication technique they could use and for each give a benefit
and a drawback.
matched triples:
User ID and password
Benefit – each user ID could be unique/only user will know the password/data can only be
accessed by person who knows the password/Password can be changed frequently to avoid
hackers guessing them/Unsuccessful logins can throw you out of the system
Drawback – user might forget password/keylogging software can be used to intercept it
Biometrics
Benefit – each user has unique biometrics
Drawback – equipment is expensive to buy/may be difficult or expensive to get equipment to user
Magnetic/chip card with PIN
Benefit – Hacker needs to have the card and know the PIN
Drawback – can lose the card/can forget PIN
TAN
Benefit – Always changing so a hacker would not be able to use it even if they intercepted it when
user typed it in.
Drawback – need to have card and remember PIN and use it within a short period of time.
13. Describe how the components of an expert system are used to help a doctor to diagnose
an illness.
Symptoms are entered using the user interface
User interface displays questions...
...based on previous responses
User answers questions using user interface
inference engine compares symptoms
compares symptoms with those in the knowledge base
compares symptoms using rules base…
…matches of symptoms are found
User interface/screen displays possible diagnoses/illnesses/probabilities
14. A bank uses a chip and PIN system at its ATMs. A customer withdraws cash by inserting
their bank card. Write down the steps involved in the computer processing of the
transaction.
The customer is asked to type in their PIN
The (ATM) checks to see if the card is valid
The customer is asked which language/currency they require
The bank account details are read from the chip
Customer is asked if they want a receipt
The typed PIN number is compared with that stored in the chip
If they are the same the transaction proceeds
If they are not the same the customer is asked to re-enter PIN
If three failed attempts transaction rejected and card withheld
The customer is asked which service is required
The customer selects required service (cash)
The customer is asked how much money they want to withdraw
The customer’s account is checked to see if it has sufficient funds
The amount is checked against the card limit
If there are sufficient funds (and the amount is within the card limit) the transaction is authorised/if
not transaction is rejected
The amount is deducted from the customer account
The bank notes are issued
The card is returned (by the computer)
If required receipt is printed.
15. A house has a microprocessor controlled burglar alarm.
(a) Identify three input devices which would be used in this system to feed data back to
the microprocessor.
Temperature sensor
Infra red sensor/Movement sensor/camera/motion sensor
light sensor
Pressure sensor/pad
Contact switch
Sound sensor/microphone
key pad/touch screen
Biometric devices
(b) Describe how a microprocessor would use these devices to detect the presence of an
intruder and what action it would take.
Microprocessor checks input from the user is authentic
Microprocessor (continually) monitors sensors.
If light/infra red sensor reading changes
If movement sensor activated...
If contact switch activated...
If pressure greater than pre-set value.....
If sound greater than pre-set value.....
If temperature greater than pre-set value....
Microprocessor sends signal to sound alarm
Microprocessor sends signal to flashing light/house lights.
Microprocessor sends signal automatically to police
Microprocessor automatically sends message/calls/texts owner
16. Mobile telephones (cellphones) are used for accessing the internet.
Give advantages and disadvantages of using a mobile telephone rather than using
a laptop computer to access the internet.
advantages:
More likely to have it with you
Can access internet from greater number of places
Easier to use while on the move
disadvantages:
Display is more difficult to see/display screen is smaller
Keyboard is smaller so more difficult to type
Some sites do not have full facilities for mobile phone
17. Describe what a virus is and what effect it may have on the data on a hard disc.
A piece of program code
Which replicates itself
Fills up hard disc making it unusable
Deletes data/changes data (from hard disc)
Makes software/operating system unusable
18. Discuss the benefits and drawbacks of students using the internet to carry out research.
Internet is not regulated
Danger of accessing inappropriate websites.
Can take long time to find required information
Have to have internet connectivity/computer/phone line/modem
Internet tends to be up to date
Internet has vast amounts of information/wide range of information
Faster to search only if referring to use of search engine
Can access biased/inaccurate/unreliable websites
Lack of expertise can lead to inefficient searching
Easy to plagiarise information
19. A group of car mechanics wants to have an expert system to help them with their work in
diagnosing car engine faults.
Describe how such a system would be created.
Data is gathered/collected from experts
Knowledge base is designed/created
A structure to relate each item in the database / knowledge base is created
An interrogation technique to access the data is created
A user interface/method of displaying the results/method of inputting data/ input screen/output
screen is designed/created
The inference engine is designed/created
The rules base is designed/created
The system is tested
20. Describe online processing of data, using the booking of airline tickets as an example.
User/customer is in direct contact with the main computer/CPU
Appears that nobody else can access system at that point/processing is almost immediate
Computer asks customer for details of flight
Computer asks for personal details of passengers
Computer searches for matching flights
Computer may display list of seats available
Computer may ask customer to select a seat
(Customer selects seat from those available and) computer flags seat as booked
Computer asks customer to complete payment details
Computer checks details are valid by communicating with customer’s bank
Computer checks if sufficient funds
Airline’s database is updated immediately
Number of seats available reduces by number booked
Prevents double booking
Confirmation/e-ticket may be sent to customer by email
21. Schools are concerned with the possibility that students are using the schools’ internet
connections to access undesirable sites.
Name and describe security methods the schools could use to prevent this from
happening.
Proxy server
The proxy server can restrict the web sites students can access/can block access to sites with
objectionable material
Firewall
Limits the computers (using IP address) that can access the system/that can be accessed from
within the school
Applying parental guidance settings.
Can block undesirable topics
22. Describe features of a graphical user interface (GUI).
Window – an area on the screen that displays information for a specific program.
Icon represents a folder or a program – can be seen within a window or freestanding on screen
Menus – contains lists of options for a certain program/software
Pointing device/Pointer – used to select menu options/icons/close/open windows
23. A head teacher wishes to publicise school activities to make his school better known in the
neighborhood. He could do this by using the school’s website or producing a magazine using DTP to be delivered by hand.
Discuss the advantages and disadvantages of each method.
Advantages of DTP (Desktop publishing)
Can be sure every local family gets to see it
Not everybody has a computer/internet/modem
Can read it anywhere/not limited to where computer is.
Disadvantages of website
Can’t be sure every local family gets to see it
Not everybody has a computer/internet/modem
Can’t read it anywhere/ limited to where computer is.
Disadvantages of DTP
Takes time to physically distribute by hand
Might need to pay somebody to distribute by hand
Costs of ink/paper/printing
Not as easy to update
Not interactive/hyperlinks
No animation/video
No sound
Advantages of website
No costs of ink/paper/printing
Easier to update
Interactive/hyperlinks
Animation/video
Sound
24. Robots are now used on many car production lines.
Describe how their use has affected the nature of employment in the car industry.
Car workers have been made unemployed
Car workers have had to be retrained
Car workers have become deskilled
More technical staff have been employed
Work areas are cleaner
There is a healthier environment
Workers have a safer environment
Fewer manual tasks
25. Ali wants to back up his data.
(a) Give reasons why making backups is necessary.
Data could be corrupted on original medium
Data could be accidentally amended/overwritten on original medium
Data could be accidentally deleted from original medium
Data could be maliciously deleted from original medium
(b) Ali thinks that making backups will prevent his data from getting viruses.
Describe what a virus is and explain why Ali is wrong.
Virus is a piece of programming code
Which replicates itself...
Can fill up storage medium making it unusable
Deletes data/change data
Makes software/operating system unusable
If the original medium has a virus the backup will have it as well/backup will have no effect on the hard disc so it is still susceptible to viruses
26. Describe differences between a blog and a wiki.
Blog usually has a single author/ a Wiki usually has many authors
Blog is usually in reverse chronological structure/ a Wiki has a structure determined by content
and users
Blog is usually personal/someone’s opinion/ a Wiki is usually objective
Can’t edit a blog/ a Wiki can be edited/ Can only add comments to a blog
27. Describe the benefits and drawbacks to companies of using video conferencing.
Benefits:
Can call meeting at short notice
No need to pay travelling expenses
Can work from home
Employees will save time travelling
Do not have to pay hotel expenses
Do not have to pay for conference room facilities
Safer as participants do not have to travel
Don’t have to transport/carry equipment/lots of documents/documents don’t get lost in transit
Drawbacks:
Takes time/costs money to learn new technology/to be trained
Difficult to have international meetings because of time differences
Initial cost of hardware (and software)
Equipment can break down/power cuts can stop conference
Poor strength of signal/time lag/lip sync can be a problem/ connection can be lost
Loss of personal/social contact
Legal documents cannot be signed
28. A greenhouse is controlled by a microprocessor.
(a) Other than a light sensor name sensors used in the greenhouse.
Temperature
Humidity
Moisture
pH
(b) Explain why computers are unable to read the data directly from these sensors and
name the device which would enable them to do so.
Sensor measures analogue
Computer works in digital
Analogue to digital converter
(c) Describe how the microprocessor uses data from the light sensor.
microprocessor compares light reading with preset value
if lower than pre-set value microprocessor sends signal to switch on light bulb
if higher than pre-set value microprocessor sends signal to switch off light bulb
process is continuous/ monitoring of sensors is continuous
29. Computers are used in supermarkets at point of sales terminals. When paying for goods the
customer inserts the bank card into the chip reader.
(a) Identify items of data contained in the chip on a bank card.