1a. A computer virus is a computer program (piece of software) that can install itself on a computer without permission or knowledge of the user and then copy itself to other programs and computers. The virus may cause damage to the computer.
1b. Barbara should install anti-virus software to make sure that her computer is free from viruses that might damage or delete her files.
She should make back-up copies on a storage device such as CD-ROM, external HD, memory stick or internet storage.
2a. A, C, B
2b. Advantage 1: microprocessors are reliable, rarely break down and are easy to fix – just plug in a new module.
Advantage 2: microprocessors are accurate so the heating system would keep the correct temperature, reading from heat sensors and controlling the heater.
3. Animations. Video footage. Spoken recordings.
4a1. Spreadsheet can create a model, take figures as inputs, process them in calculations and present the results as outputs.
4a2. Spreadsheet has functions such as SUM and specialised ones for financial calculations such as compound interest and payments over a given period at a given rate of interest.
4b. Get someone else to check it. Check the entries and read them out loud while doing this.
4c. Copy and paste the figures from the spreadsheet into the document – this makes a static copy that does not change when the spreadsheet changes.
Use Paste/Special to make a dynamic copy that changes when the model changes.
Also: Convert the output to chart format.
5a. One way to use ICT in a shop is to install an Electronic Point of Sale (EPOS) system. This includes a till with a bar code reader that is connected to a computer. The computer has a database containing the codes for the products sold in the shop. When an item is sold its barcode is scanned and the code is looked up on the computer. The price of the item is sent to the till so it can calculate the total bill and print each item on the receipt.
5b. The computer that stores the prices of items can also store the total number of each item in stock. At the same time as the price of the item is retrieved from the computer the number of items purchased is taken away from the number in stock so the number remaining is kept up to date. When the number in stock falls below a certain level the shop keeper can be told to buy more.
6ai. Numeric key pad, driver opens window and types it in. Magnetic card swipe, number encoded on magnetic stripe, driver runs it through the reader. (Also: barcode, voice recognition, biometric scan, OMR)
6aii. Numeric key pad is cheap and easy to use.
6b. Use a sensor that detects a car as it passes through the barrier, for example when a valid code is entered and the barrier is raised. Count each car as it leaves the car park e.g. when the code is entered as the car leaves. The cars entering minus the cars leaving will give the total number in the car park. The capacity minus the cars in the car park will give the number of spaces.
7. Advantages of email:
Email is delivered quickly, in many cases almost instantaneously, anywhere in
the world. Some servers may have a delay but email will still be quicker than
using the post.
You can send attachments such as documents and pictures and include hyperlinks to web pages.
Email can send the same message to many people at once which saves a lot of work and is probably cheaper too as you don’t need to print many copies, have a secretary print them and pay for postage on each one.
Email may be cheaper than the post. Once you have paid for the computer and the internet connection you can send as many emails as you like for no further charge.
Disadvantages of email:
If the computer, the email server or the internet connection fails an email cannot be sent.
Some people may not have an email account (but most people have an address).
Unencrypted email (the vast majority) may be insecure and intercepted.
You can’t send parcels or cards (birthday, Christmas) by email.
8ai. It is easy and quick to find names in a computer database. You can search for people on criteria such as ‘last appointment > 6 months ago’.
Computer databases can be made secure by password and encryption.
Computer databases can be backed up so they cannot be lost.
Disadvantage: If the computer fails the database is inaccessible. Forget password? Forget to back up?
8bi. Validation is checking that data is reasonable, within a range of limits such as between 10 and 100.
8bii. The day field could be checked to make sure it is in the range 1-31. The month field could be checked to make sure it is in the range 1-12. The day and the month could be checked to make sure they match e.g. 30/2 is out of range. The year should be no greater than this year or the next. The date could be checked to make sure there are no letters in it.
8c. Many people can share the same last name so it cannot be used as a key field. You have to be able to have more than one Smith or Patel in the database.
9. Presentation software would be good for this task because Casper can have as many slides as he needs to show the information. Having many slides means the information can be broken down into small sections or chunks.
The slides may use a template so they have a consistent appearance. Casper can use a separate slide for each photograph that he has taken. He can use the slide design facility to place a photograph on a slide with text alongside so that the audience can follow the points he makes.
He can add words to the slide to remind him of what he wants to say about it. He can add detailed notes in the Notes section of the presentation, which he can print out and distribute to members of the class.
He can order the slides into the best possible sequence so that he can link them by theme. He can add animation to make the presentation more interesting and to leave out information until he is ready to introduce it. He can save the presentation on a memory stick and take this to school for a lesson.
10. One advantage of having a computer at home is that a lot of the research
into a family tree can be done at home without the need to travel to libraries
or other organisations such as the national records office.