WAEC SSCE - Data Processing - 2021 (Essay and Test of Practical Work)

Détails de la réponse

This question tests ways of classifying computers, the digital/analog distinction, ICT impact and transmission media.

(a)(i) Three ways of classifying computers.

• By size (supercomputer, mainframe, mini, micro).
• By type/data handled (digital, analog, hybrid).
• By purpose (general-purpose and special-purpose).

(a)(ii) Digital versus analog computers. A digital computer works with discrete data represented as digits (binary 0s and 1s) and gives exact, countable results (for example a desktop PC). An analog computer works with continuous physical quantities that vary smoothly, such as voltage, temperature or pressure, and measures rather than counts (for example a mercury thermometer or a speedometer). In short, digital counts discrete values while analog measures continuous values.

(b) Three positive impacts of ICT on society.

• Faster and easier communication (email, video calls, social media).
• Improved access to education and information through the Internet.
• Efficiency in business, banking and government services (e-commerce, e-banking).

(c) Two types of information transmission medium. Guided (wired) media such as twisted-pair, coaxial or fibre-optic cable, and unguided (wireless) media such as radio waves, microwaves or infrared.

Examination reminder: the digital/analog difference is discrete vs continuous data; and transmission media split neatly into guided (cable) and unguided (wireless).

Détails de la réponse

This question tests disk and data-management terms and the uses of the ATM.

(a) Definitions.

• (i) Disk formatting: the process of preparing a storage disk for use by organising it into tracks and sectors and setting up a file system, which erases any existing data on it.
• (ii) Data backup: making and keeping an extra copy of data on another storage medium so that it can be recovered if the original is lost, corrupted or damaged.
• (iii) Virus scan: the process by which antivirus software examines files, storage devices or memory to detect, and then remove or quarantine, computer viruses and other malware.

(b) Four uses of the Automated Teller Machine (ATM).

• Withdrawing cash from an account.
• Checking the account balance.
• Transferring money between accounts.
• Paying bills and buying airtime (also requesting a mini statement or changing the PIN).

Examination reminder: keep the definitions distinct - formatting prepares/erases a disk, backup duplicates data for safety, and a virus scan detects and removes malware.

Détails de la réponse

This scenario tests workstation safety, computer maintenance and the health risks of computer use.

(a) Two safety precautions to protect workstations from food and drinks.

• Prohibit and enforce a no-eating and no-drinking rule in the computer area (display "No food or drinks" signs).
• Provide keyboard covers and keep food/drinks in a separate area away from the machines.

(b) Two ways to maintain the computers for efficiency.

• Regularly clean the systems (dust the components, keyboard and screen) and service the hardware.
• Keep antivirus software and system software updated and run regular virus scans and disk clean-ups.

(c)(i) Three possible health risks to users.

• Eye strain (visual fatigue) from staring at the screen.
• Back and neck pain from poor posture.
• Repetitive strain injury (RSI) in the wrists and fingers from prolonged typing.

(c)(ii) How the risks can be reduced.

• Take regular breaks and look away from the screen (use an anti-glare filter and correct lighting) to reduce eye strain.
• Use an adjustable, ergonomic chair and sit upright with the screen at eye level to reduce back and neck pain.
• Use a wrist rest and correct hand position, and rest the hands regularly, to reduce RSI.

Examination reminder: pair each health risk with a matching remedy - eye strain with breaks/anti-glare, back pain with ergonomic seating, and RSI with wrist support and rest.

Détails de la réponse

(a) Completed Table 1 - Criteria for each storage medium.

Each medium is compared by where it is located, whether it can be removed, and how files are accessed on it.

Reasoning: A hard disk is normally fixed inside the system unit, so it is internal and non-removable, while a DVD-ROM and a magnetic tape are inserted into a drive from outside, so they are external and removable. Both the DVD-ROM and the hard disk allow the read head to jump straight to any location, giving random (direct) access, whereas a magnetic tape must be read in order from the beginning to the required record, giving sequential (serial) access.

(b) Three examples of spreadsheet applications:

• Microsoft Excel
• Lotus 1-2-3
• Apple Numbers (or Google Sheets / VisiCalc)