P1

Question 1

Logic gates hierarchy

Answer 1

Not
And
Or

Question 2

compatibility issues that may occur when two information technology (IT) systems are merged.

Answer 2

Application software cannot run on a particular CPU architecture;
Software cannot run on an operating system;
Computer hardware components may not run with a CPU architecture/bus/motherboard;
Inability of software to interact with files;
Different data representation (units/conventions i.e., dates/currency etc.);

Question 3

Identify two usability problems that can occur in a voice recognition system

Answer 3

number of rejected/hypothesized words (speech commands); number of audio signal issues (users being either too loud, too slow or too fast/noisy environment – means decreased accuracy of speech recognition); difficulty distinguishing between similar sounding words; different dialects/accents which the system may not be able to deal with; limited database of commands;

Question 4

State three pieces of information that a data packet must contain.

Answer 4

Data; Protocol; Packet number; Total number of packets; Sender’s IP address; Receiver’s IP address; Control bits/Parity bit/Check digit/Time to live (hop limit);

Question 5

Outline what is meant by a virtual machine.

Answer 5

A virtual machine (VM) is software that runs programs; without being tied to a physical machine

Question 6

Identify three functions of the control unit (CU) in the central processing unit (CPU).

Answer 6

Fetches/extracts each instruction from memory;
Decodes/transforms them into several commands/signals/steps (that are passed to the ALU or I/O
or other components in the CPU for execution);
Controls the movements of data within the CPU;
Generates the clock pulses that regulates speed of the instruction cycle;
Generates control signals for all hardware components to regulate their activities;
Synchronizes all the operations of the CPU;

Question 7

Explain the use for VPNs

Answer 7

Security when working remotely;
VPN’s data encryption features (putting data into a coded format so its meaning is obscured)
before giving the access to data;
VPN allows access to any content in any place;
Because it enables users to send and receive data across shared or public networks as if
their computing devices were directly connected to the private network;
VPNs hide the location/hidden IP address;
Protects the privacy of data;
A VPN will prevent apps and websites from attributing the doctor’s behaviour to her
computer’s IP address/can limit the collection of the location and browser history from the
Internet Service Provider(ISP);

Question 8

Outline the function of a web browser.

Answer 8

web browser allows users access to information/resources on the WWW;
(when a user asks for a particular website) the web browser fetches the required content
from a web server/ acts as an interface between a client and server;
prepares the retrieved information to be displayed/ interprets the content to be rendered in
a format that can be understood/ displays the resulting web page on the user’s device;
allows user to navigate around website/ open more than one web page/ print/ save page/ etc.

Question 9

Outline one reason for using Unicode to represent data in a computer system.

Answer 9

Because Unicode is (an established) standard for data representation/ a single encoding scheme
for all languages and characters;
Because of the difference between ASCII and Unicode in the number of bits used to encode
(ASCII (8-bits) and Unicode (16/32 bits);
It can represent over a million characters/ ASCII cannot be used to encode the many types of
characters found around the world;
Because Unicode can be defined with different character encoding like UTF-8, UTF-16, UTF-32,
etc.;
And is used to represent many (over a million) characters from many (more than 150) modern and
historic scripts (along with emoji)

Question 10

Explain the use of cache memory.

Answer 10

Cache memory is (an extremely) fast memory type;
that acts as a buffer between RAM and the CPU;
it holds frequently requested data and instructions;
so that they are immediately available to the CPU when needed;

Question 11

Outline what is meant by a collection.

Answer 11

A collection is a term used to describe a data structure designed to contain multiple elements of
any type;
and methods which make this data useful; Accept example methods, such as methods given in IB
pseudocode: hasNext(), getNext(), resetNext(), etc. ;
Collection is a container of discrete values;
Usually of the same type (primitive data values and also some other data
structures);
(But) collection objects can be of different types (pointers afford a flexibility and thus collection objects permit references to any data structure as well as to primitive values);
Collections have a set of methods that define operations performed on the elements/objects of that collection;
Which reduces programming effort (because implementations of data structures
and algorithms are provided);
Which increases performance of the program (because efficient implementations
are provided);

Question 12

Outline what is meant by the term “abstraction”.

Answer 12

one of the key concepts of OOP languages;
to decompose complex problems;
Hide / remove unnecessary details;
look for recurring patterns;

Question 13

Outline the meaning of the term “legacy system”

Answer 13

Legacy system is an outdated computer system/(application) software that is still in use/ still
meets the needs it was originally designed for/ is essential for the organization;
it cannot be updated /does not receive support and maintenance/ doesn’t allow for growth/ is
incompatible with current (new) more advanced solutions;

Question 14

Explain one problem that may occur during data migration.

Answer 14

Data loss/data available in legacy system but after migration process it is not available in the
new system;
because data is accidentally deleted/ something causes data to become corrupted/ viruses/
physical damage/incomplete transfer;VPN
cost involved in rectifying data loss leads to financial risk for the organization / sets back
productivity / reputation risk (can cause the organization to lose customers);

Data Corruption/ Data integrity;
format and content of data in legacy system and new system is different / incompatible data/
anomalies or redundant or duplicated data or presence of non-meaningful data;
this affects the efficiency/ it can totally beat purpose of migration;

Question 15

State two technologies that are required to provide a virtual private network (VPN)

Answer 15

(VPN) tunnelling (server);
(VPN aware) router (and firewall);
Encryption (protocol) (Accept examples IPSec/ SSL / TSL);
VPN client software (installed on the employee’s computer);

Question 16

Explain why data compression would be used when data is transmitted.

Answer 16

(Because) compression reduces the size of a file/ size of data/ the number of packets to be
transmitted;
Which reduces transmission time/ consumes less bandwidth;
And can result in significant cost savings;

Question 17

State two characteristics of a linear array.

Answer 17

Predetermined size (size should be known in compile time / it should be known in advance
how many elements are to be stored in array);
Fixed size (once the memory is allocated to the linear array, it cannot be increased or
decreased);
An array holds elements that have the same data type;
Array name represents the address of the starting element, all elements of an array can be
distinguished using an index number (direct access to each element);
Array elements are stored in subsequent memory locations;

Question 18

Identify two differences between a wide area network (WAN) and a local area network (LAN)

Answer 18

WAN covers a much larger area (national/international), LANs usually cover a smaller area
(such as a single site);
LANs are more secure than WANs (due to how WANs transmit the data /how far the data would
need to travel);
A higher bandwidth is available for transmission in a LAN than a WAN/ LANs can have a
higher data transfer rate than a WAN;
LAN is typically cheaper than WAN to implement/ maintain (as the equipment required for LAN is
less expensive);
WAN includes a large number of devices connected together, LAN includes less;
WANs are typically slower than LANs due to the distance data must travel;

Question 19

Identify one function of a single-user operating system.

Answer 19

Memory management

Question 20

Outline one reason for the use of standards in the construction of networks.

Answer 20

Standards ensure compatibility between nodes on the network;
Through the use of common techniques/protocols/language;

Question 21

Describe two appropriate techniques to gather the information needed to find a suitable solution for the updated system.

Answer 21

Examining current systems (using interviews/ surveys/direct observation);
To compare the existing system against possible requirements to identify missing features;
Examining competing products;
To compare own system with competitors to enable decisions on features to add;
Review of organizational capabilities;
To determine how well the organization manages resources to gain an advantage over
competitors;

Question 22

Identify two fundamental operations of a computer.

Answer 22

Add;
Compare;
Retrieve;
Store;

Question 23

Define the term variable

Answer 23

Variables define areas in memory in which values (data) are stored;
Variables are unique identifiers that retrieve values from the memory addresses at which they are
stored;
Variables are the names one gives to computer memory locations which are used to store values in a computer program;

Question 24

Identify two roles that a computer can perform in a network.

Answer 24

Client; Server/email server/DNS server/file server; Router; Firewall;

Question 25

Identify two methods that can be used to obtain these patches.

Answer 25

Automatic patches/updates sent (via internet); User requested updates (via internet); Patches sent on CD/DVD/memory stick;

Question 27

Describe two hardware components the school will need to implement the wireless network.

Answer 27

(Wireless) router; A central hub for all the computers to connect to; Enables wireless network packet forwarding and routing; Wireless Network Interface Card (NIC); To allow the computer to ‘talk to’ the (wireless) router; Wireless access points; allow Wi-Fi devices to connect to a wired network; Wireless repeaters; To expand the reach of the network;

Question 28

Outline the benefits of using subprograms

Answer 28

reusability, modularity, maintainability, readability These sub-programs (sorting/searching) could be used in (many) other programs; Which saves programmer’s time/ effort;

Question 29

Suggest two design considerations that could be made to an algorithm that would make it more efficient.

Answer 29

The algorithm could use loops; To remove the necessity to process extra lines of code; Use of arrays/data structures; So data can be stored/re-used/re-entered; Use of flags; To stop a search routine when an item has been found so that all elements don’t have to be searched;

Question 30

State two differences between primary storage and secondary storage.

Answer 30

Primary storage is accessed by a computer's central processing unit (CPU) and secondary storage is not accessed directly by the CPU; Primary storage has lower access time / has smaller capacity/ more expensive type of memory than secondary storage (which is slower than primary storage, with larger capacity but it is cheaper); Primary storage is volatile (uses random-access memory (RAM), cache memory, or some other specialized hardware to store data while the computer is powered on/ volatile devices), whilst data is kept permanently/ for a long time in secondary storage;

Question 31

Outline why computers use the binary number system.

Answer 31

because the binary system uses only two digits (0 and 1); and computer uses bi-stable devices / devices that can be either in one of the two possible states (such as pulse or no pulse, on or off, 0 or 1, true or false) /;

Question 32

Outline why a sub-program is considered an example of abstraction

Answer 32

A sub-program is a named section of code that performs a specific task (in a program) / can be called by name / referred by the identifier when needed; without knowing the details (of code and data structures) as these are wrapped / hidden within the sub-program;

Question 33

Explain how corrupted data files can be recovered.

Answer 33

Restore files from a backed-up data file; ensuring it is a recent copy to minimize loss; a parallel/failover system could be operated; that could be switched to (if the live system is corrupt); data recovery software could be (installed and) run; to repair corrupted files;

Question 34

Outline one feature of a word processor that could reduce the amount of typing required when writing letters.

Answer 34

Auto-correct/short sequences/codes; can be used to represent longer phrases; Mail merge; allows production of many letters by only typing the (body of a) letter once; Voice recognition; allows easy entry of text;

Question 35

State the purpose of technical documentation provided with software.

Answer 35

Technical documentation explains how to install software; Technical documentation describes the hardware configuration/operating system needed (to install this software);

Question 36

Define the term client

Answer 36

A client is a simple application or a whole system that accesses services being provided by a (remote) computer/server;

Question 37

Define the term server.

Answer 37

A server is a computer/software that provides data to other computers/ clients in a network;

Question 38

Explain the functions performed by the server

Answer 38

can manage several clients simultaneously (in order, each providing a different set of services); makes sure that the request is valid by accessing its database; processes the request; sends information to client; all requests/information are sent over the network connection;

Question 39

Describe the role of a router in this network

Answer 39

controls the flow of data in the network; inspects address of data packets; directs to the appropriate network path/ selects a path between networks (by inspecting address of data packets); securely transmits data packets (across that path toward the intended destination);

Question 40

Outline two reasons why there might be a reduction in data transmission speed at certain times.

Answer 40

malicious software/spyware/malware / viruses; attacking the system; the type of connection; valid outline for the slow down (depending on the type of connection); hardware malfunction; internet speed can considerably slow down if modem-router configuration is not correct / updated; external factors; during the peak hours of daytime the most visited websites encounter more network traffic than what has been anticipated;

Question 41

Identify two usability factors that need to be considered in the design of a website

Answer 41

complexity / simplicity / amount of effort to get a result / number of errors with the time taken to move past them; readability / comprehensibility / reading or writing speed; learnability / time to accomplish tasks on the first use; effectiveness ( user performance); efficiency (time needed to complete a task);

Question 42

Outline one reason why visual displays on a computer screen can create difficulties for some people.

Answer 42

Visual display design is not logical; workflows are not simple, and do not require as few interactions as possible to complete; Visual display design is not consistent; navigation, header, footer, and main content are not always in the same places; Visual display design is not usable as possible; tools are not easy to use, processes are not broken down into logical steps; People with poor eye-sight/color blind can have difficulties to distinguish; because of the way graphics, words and directions are used / combinations of some colours (eg, red and green);

Question 43

Explain how the operating system ensures that each customer’s data is secure when multiple users are accessing the data at the same time.

Answer 43

OS (memory management function) allocates / deallocates memory to each process/customer task, and guarantee each customer task the resources it needs to run correctly; moves processes back and forth between main memory and secondary memory during execution to prevent overwriting / accidental interchange; and control access rights to the specified memory area (for example, prevents write access to the memory which is not allocated to the process/ customer task); and protects data / applications when in memory / RAM from malicious code (prevents Attempts to execute the contents of the partition/ allocated memory);

Question 44

Explain why there could be ethical issues for the company when sharing its customers’ data.

Answer 44

privacy of customer/ person data; company needs to gain permission from customer; customer would need to be able to view all data details; customer must be informed about all uses that will be made of data; customer must be informed to whom data will be disclosed. legal issues to do with unauthorized disclosure of customer data;

Question 45

Identify two features of a graphical user interface (GUI).

Answer 45

Menus; Dialogue boxes; Windows; Icons; Pointers; Buttons;

Question 46

Outline the purpose of the memory address register (MAR) in the central processing unit (CPU).

Answer 46

The MAR holds the memory location of data/instructions; …that need to be accessed (read/write) (fetch/store);

Question 47

Compilers translate source code into object code. Identify two other operations performed by a compiler

Answer 47

Pre-processing; Lexical analysis; Parsing; Semantic analysis; Syntax analysis; Linking; Optimisation;

Question 48

Outline one reason why protocols are used in communications between computers.

Answer 48

To provide a set of rules/procedures; To enable two or more different electronic devices/computers/entities to understand each other during data transfer / enable successful communication

Question 49

Identify two characteristics of a personal area network (PAN).

Answer 49

Smallest type of network; Consists of connected devices in close proximity to the individual using them; Connected via Bluetooth/wireless; Suitable example: smartphone to car connection;

Question 50

Describe two possible causes of data loss.

Answer 50

Malicious activities; An unauthorized user gaining access to data and deleting/altering it; Natural disasters / earthquake / storm / power loss; Causing the system to crash and destroy data; Malware/viruses/spyware/worms; Which infiltrate and damage the data; Human error; Accidental deletion/overwriting of files;

Question 51

Explain why beta testing is used to gather feedback for the new user interface.

Answer 51

Testers outside the organization use the operating system in a “real world” setting; Enables feedback to be given to the developers; So that the software can be improved/corrected/debugged; Before it is finally released; “Real world” testers may find more bugs as the system is used in ways not originally intended / tested;

Question 52

Identify two characteristics of RAM

Answer 52

RAM is volatile / contents erased when power is switched off; Access speed is fast / faster than hard drive; Data / instructions can be read from and written to it / /RAM can be overwritten; Size is limited;

Question 53

State the purpose of persistent storage on the computers.

Answer 53

To store programs / files / data in a non-volatile device so it isn’t lost; Stores more data as it has a larger capacity;

Question 54

Identify two types of general application software that would be installed on the training computers.

Answer 54

email, web browser, spreadsheet, word processor

Question 55

The company has decided to allow the teachers to use their own devices in its training room by adding wireless networking. (d) (i) Outline one advantage to the company of implementing this change.

Answer 55

May save money; Due to not having to supply all the training computers; May be able to increase the size of the training group; Which may generate more income; Trainees / teachers likely to be more familiar with software on own machine (and how new training software interacts with OS / user interface); Making training sessions more efficient / allowing trainer to concentrate on the training rather than using generic applications;

Question 57

The company has decided to allow the teachers to use their own devices in its training room by adding wireless networking. Outline one disadvantage to the company of implementing this change.

Answer 57

May cause security issues; Due to multiple users having network access from their “unsecured” devices; May interfere with running of training sessions; As some machines may not be compatible;

Question 58

Distinguish between fundamental and compound operations of a computer.

Answer 58

Fundamental operation requires one machine instruction cycle/do not require the processor to go through many machine instruction cycles to reach a result; A compound operation is complex / it is an operation that involves a number of other operations to reach the result; For example, find the largest number in an array/ sort the array in ascending order etc;

Question 59

Explain the purpose of cache memory

Answer 59

Cache memory is a memory that a computer microprocessor can access more quickly than it can access regular RAM; stores frequently used data only until a computer is powered down; Thus, when a processor requests data that already has an instance in the cache memory; it does not need to go to the main memory or the hard disk to fetch the data; Cache memory can be primary or secondary cache memory, where primary cache memory is directly integrated to the processor; And secondary cache memory is a reserved portion on a disk stores and provide access to frequently accessed data/applications from the disk

Question 60

State why hexadecimal numbers are frequently used in computing.

Answer 60

Hexadecimal numbers are used for shorter representation of data because a (modern) byte can be represented exactly by two hexadecimal digits; Hexadecimal numbers are used for shorter representation of data, because computers store and handle binary digits, and four binary digits make one hexadecimal digit;

Question 61

State the number of bits used to represent a non-primary colour, such as yellow.

Answer 61

24 (6 digits, 4 bits per digit)

Question 62

Discuss the social and ethical issues associated with the introduction of a new computer system.

Answer 62

Personal/professional development of all employees must be considered; Physical safety (of all users); Ergonomic standards (human-computer components); Human dignity of all users; The new system might be designed to replace some staff; Code of ethics (system resources should not be used without approval);

Question 63

Outline two advantages of a school using a computer network.

Answer 63

File sharing/resource sharing; instead of using a disk or USB key to carry files from one computer to another files can be shared directly using a network/all computers in the network can share resources such as printers, scanners; Improved network security; if the school has its own network, it can monitor network traffic / can create a security culture (everyone who has a username and password is responsible for keeping data secure);

Question 64

Describe the purpose of Network interface card (NIC)

Answer 64

Network interface cards are used to connect each computer to the network; so they can communicate with the network router to receive information Packets;

Question 65

Evaluate the use of trusted media access control (MAC) addresses as one method of network security.

Answer 65

Each (wireless network) adapter has a unique label called a MAC address; Routers uses these addresses to identify/authenticate computers (routers include an option to whitelist or blacklist certain devices based on MAC addresses, so access could be restricted to any device which is not in the whitelist); One disadvantage is that the whitelist should be amended any time a new device is purchased / when access to guests should be granted; Also this method is useless against hackers who use programs which intercept data passing through network and report the MAC address of any device communicating on the network

Question 66

Explain the importance of the memory management function of an operating system.

Answer 66

Allocates and de-allocates memory/ assignes blocks of memory to programs; Ensures a program has sufficient memory to run/manages virtual memory if needed; To avoid overwriting /clashing of programs/optimise system performance/maximise memory usage

Question 67

A WLAN will introduce additional security issues for the company. (e) Discuss any two of these issues and the ways in which the company might resolve them.

Answer 67

The data can be intercepted as it goes through “the air”; Can be resolved by strong encryption/protocols; WPA-2 / a description of WPA-2; Use of trusted MAC addresses; Regular changes of router password; [2 max] BYOD issues leading to insecure devices; Clear company policy regarding use; Use of sand-box; Only approved devices allowed; MAC addresses – only adding clean and tested devices brought in by staff; Installation of MDM services; Authentication (user ID + password on all devices including BYOD); Security features added by company;

Question 68

Outline two advantages, to this company, of installing a WLAN.

Answer 68

Use on the move; More versatile staff encouraged to collaborate etc.; Allows BYOD: Which could lead to greater productivity (as familiarity with device); No extra equipment is needed for expansion after initial set-up; Which will save the company time and money; Reduces wiring; Therefore improved safety for employees;

Question 69

The company is considering expanding their network to allow employees to connect from anywhere in the world. The expanded network would need to provide security and allow the employees full functionality of the internal network. (f) Explain how setting up a virtual private network (VPN) would provide a suitable solution.

Answer 69

A VPN/tunneling allows the employee’s device to appear to be part of / a node of the internal company network; Thus affording him/her full access to the network resources; Data that passes through a VPN can be encrypted; So any unauthorized access will not be able to understand the data; Multiple exit nodes / hidden IP addresses/encrypted connections; Make it hard to distinguish where the data was generated;

Question 70

Outline what is meant by the term computer network.

Answer 70

A group of computers and other computing hardware devices that are linked together through communication channels/cables/wirelessly; To enable communication (sharing files, sharing information) between systems/among a wide range of users;

Question 71

Outline what is meant by a database management system.

Answer 71

Database management system is an application software; that allows users to define/create/maintain a database / provides (controlled) access to the data; Examples of database applications are computerized library, inventory, flight reservation, etc;

Question 72

Outline one advantage of using beta testing prior to the release of a new product.

Answer 72

Beta testing is done from the user/client perspective; So, requirement mismatches can be easily identified; The real users have an opportunity to test a new product before it is (publicly) released; So, user acceptance is assured; Any bugs identified could be (easily) fixed before the public release of the product; So, quality of the product is enhanced;

Question 73

Outline the function of an operating system in managing primary memory

Answer 73

A part of the OS (memory manager) assigns that block of memory to the program when a running program requests a block of memory; When the program no longer needs the data in previously allocated memory blocks, they become available for reassignment; OS ensures the availability of adequate memory for data structures/objects of each running program at all times; By allocating the memory portions to programs after freeing the space (of the computer memory); OS (memory management unit) uses virtual memory which provides secondary memory (external storage) for program that does not have enough space in RAM for execution; After execution of the program this memory is reallocated (used by other programs)/freed;

Question 74

Explain the roles of the data bus and the address bus in the machine instruction cycle.

Answer 74

Bus is defined as a system that transfers data between hardware components/data bus and address bus enable a processor to communicate with the primary memory; When the computer processor needs to fetch an instruction from the memory it uses the address bus to specify the (physical) address (of the memory block it needs to access); It will get the data from (the specific) memory (block) (after checking the address bus to get the read address); And then it will place this data on to the data bus/data bus carries the data;

Question 75

Outline the need for higher level languages.

Answer 75

Higher level languages are closer to human language; So programmers find them easier to understand/work with than lower level languages; HLL saves programmer from knowing details of computer architecture (and using all the specific (machine) instructions); So giving more time to creating/developing the best way of coding a problem/process of coding is simpler and more understandable;

Question 76

Explain how compression of data may lead to negative consequences.

Answer 76

Some compression methods (lossy) discard data; Decompression will not return the complete file/some detail will have been removed; If original not saved/lost there is no way to recover it;

Question 77

Other than the use of different keywords, outline two ways in which two higher level languages might differ from one another.

Answer 77

Method of translation; Whether by compiler or interpreter (or both); Loosely/strongly typed; Refers to whether data types are specified; Different programming paradigms; Procedural or object oriented etc.; Purpose of the language; Specific (eg scientific/AI) or general; Compatibility with different environments; Java with virtual machine can run on all O/S / some languages are O/S specific; Syntax differences; Structure of statements etc;

Question 78

Other than data migration, describe two aspects of change management that may arise from this takeover.

Answer 78

Workforce issues; Such as redundancy/retraining; The time frame involved; In merging the two systems; Testing; Of the combined systems/new data; Data entry; If migration not possible; Costs involved; In the aligning of the two systems; Changeover decisions; Such as parallel running etc;

Question 79

Discuss the importance of protocols in ensuring the successful preparation, transmission and delivery of data using packet switching.

Answer 79

Packet switching involves splitting data into packets to transmit to a specific destination; Protocols are rules/standards used to compile and transmit each packet in a standard format; Essential that all packets are constructed exactly the same; So that the receiver knows automatically how to decode the contents/does not need further instructions for decoding the packets; Protocols include destination information that means that at each node the packet passes through it is sent to the next node towards the correct destination; Packet number essential to be included for reassembling at the other end as not all packets will arrive in order;

Question 80

Identify two essential features of a computer language.

Answer 80

Fixed vocabulary; Unambiguous meaning; Consistent grammar; Consistent syntax; Provide some kind of loop that can be stopped / conditional statement / branching (conditional and unconditional branching);

Question 81

Two fundamental operations of a computer are add and retrieve. State another two fundamental operations.

Answer 81

Compare (accept Check); Store (accept Write / Save);

Question 82

Define the term bit.

Answer 82

Binary digit; (Minimal) unit of storage that can be set to 0 or 1;

Question 83

Outline two disadvantages of this WLAN.

Answer 83

Data transfer will decrease (compared with a wired LAN); Because the number of computers using the network increases; (and because) WLAN has lower bandwidth than a wired LAN; Less data security; As devices from outside the school can access the network/intercept transmissions; More easily open to misuse; As teacher/administrator cannot directly monitor a specific student/teacher/ machine; Intermittent connectivity due to physical barriers (walls); Results in low transfer/speed and may hinder operation

Question 84

Outline one problem of maintaining legacy systems

Answer 84

Maintaining previous/outdated computer system, which uses old technology and old application programs ; That are hard to understand/expensive to change/evolve because programs might be disorganized/ documentation might be missing/incomplete/unreliable; Compatibility issues (typically refer to old programming languages/old database technology); Maintaining but not updating the old system can lead to compatibility / security issues; It may be difficult to recruit staff/programmers familiar with old languages/operating systems;

Question 85

Discuss one advantage and one disadvantage of printed material, when compared to online support, as a method to provide user documentation.

Answer 85

Portability; Printed material is more easily transportable and can be moved around Readability; Font size online can be (easily) magnified; Trouble-shooting/cross-reference/usability; Online is faster and usually has links to other pages whereas paper is a thick manual Environmental; Waste of paper versus energy consumption;

Question 86

Outline the use of a failover system

Answer 86

A failover system is a standby/redundant system; Which is used to eliminate/reduce the impact on users/owners; By automatically taking over if the primary system suddenly becomes unavailable;

Question 87

In the given context, distinguish between Ethernet and wireless in terms of reliability of transmission.

Answer 87

WIRELESS The reliability of wireless depends on the strength of the wireless signal/distance from router; on the topology/shape of the surroundings; on interference/number of simultaneous connections on an access point; ETHERNET Ethernet is more reliable as the strength of the signal is independent from the distance from the router (within the college); There is no issue with the topology/shape of the surrounding, as long as the user has a connection; connection depends on condition of cables – no loose or broken cable connections;

Question 88

Describe two features of a VPN that make it secure.

Answer 88

Authentication; Nobody outside the VPN should be able to affect the security property of the VPN (it must be impossible for the attacker to weaken/change encryption); Encryption; Data intercepted will not be readable; Tunnelling software; Security properties of each tunnel should be agreed by the administrators of the two endpoints of the tunnel; Multiple exit nodes; Makes it hard to distinguish where the data was generated thus more secure (less prone to phishing);

Question 89

Identify two reasons why consistent grammar and syntax should be essential features of a higher level programming language.

Answer 89

Easy to learn/use; Otherwise time may be wasted learning the new language/writing programs in this HLL; There will be no/less compilation errors; There will be no/less logical errors; (Reduction of time to create software;) Future maintenance/development is possible by other programmers;

Question 90

Identify two features of a user interface that will allow application programmers to interact more easily with the programming language.

Answer 90

GUI; Toolbars; Menus; Built in commands for inputting from touch screens; Predicted text so that typing a class name followed by a full stop will bring up a list of methods/attributes; Automatically use a colour to represent keywords/variables and improve readability

Question 91

Describe one advantage to application programmers of having both an interpreter and a compiler available.

Answer 91

Interpreter is faster/immediately warns about syntax errors/executes commands and they could use it instead of the compiler while coding and debugging their programs; Compiler is required when there is a need to produce an executable version of a Program;

Question 92

Outline the concept of the Open Systems Interconnection (OSI) model in communication across a network.

Answer 92

The OSI is a standardized system/model for network connection; Consists of (7) layers; Each dealing with specific parts of network communication; For example the physical layer which defines the physical connection;

Question 93

Explain how the lists could be used to merge the data from the database with a word processor to create these messages automatically for sending either by post or by email.

Answer 93

Template for each type of reminder created in the word processor; Lists created with customer ID; Linked to customer details in database; Appropriate details merged/inserted into template; Email lists created and sent / letters printed and sent;

Question 94

Compare the use of two arrays, to hold the competitor’s times and names, with the use of objects.

Answer 94

The problem with parallel arrays is the sorting/indexing/maintaining relationship; An object would contain at least a name and a time (accept other descriptions of object); Would only need to sort the array of objects / only one list to be sorted;

Question 95

Describe two types of documentation that should be provided with the software package

Answer 95

Technical documentation; Describes how to install software; Describes the hardware configuration needed; User documentation; Describes various functions of the software; Helps users to learn how to use the software;

Question 96

Outline how a colour can be represented in a computer.

Answer 96

A colour will be split into three components (Accept RGB as an example); Each component will be assigned a certain number of bytes;

Question 97

Identify two key features of a peer-to-peer (P2P) network.

Answer 97

No central server; Resources are more widely available (storage, bandwidth, computing power); Redundancy/recovery; Supports file sharing for collaborative work;

Question 98

Explain why an object is an example of abstraction

Answer 98

An object hides the details; Yet preserves the functionality; OR Objects combine abstractions of data and code; While hiding away implementation of details;

Question 99

Describe the features of SaaS.

Answer 99

Data is in the cloud/computing infrastructure; SW necessary for the activities is in the cloud; Access to SW is with thin client (terminal/computers) by web browsing (on the extranet);

Question 100

Discuss the limitations of SaaS in relation to security.

Answer 100

Security in storage; Data is stored in the server of the service provider; The organization has no direct control of its data; Legislation in the country of the provider may be weaker than in the user’s country; Cases of provider’s corruption/bankruptcy/data loss are a risk to the organization; Security in transmission; Applications running in-site may require data in SaaS; Hence longer transmission times and higher risk of failure/attack/interception;

Question 101

Define the term extranet.

Answer 101

An external extension to a company’s local network; Limited access; Uses internet protocols;

Question 102

Distinguish between a VPN and an extranet.

Answer 102

VPN authenticates the sender before (establishing the tunnel); VPN access is always encrypted, whereas extranet has limited encryption; VPN transmission is always encrypted; VPN users have access to everything whereas extranet users only have access to (enabled) specific services;

Question 103

Outline the relationship between binary and hexadecimal.

Answer 103

Binary numbers have base 2, hexadecimal numbers have base 16 (24 =16); Each digit (letter/number) in a hexadecimal number can be represented by the group of four binary digits;

Question 104

State three advantages of using sub-programs in solving programming problems.

Answer 104

A large/difficult program could be divided into smaller/easier parts (sub-programs); A sub-program could be used many times in this and other programs; A sub-program could be written independently; A sub-program could be tested independently; Easier maintenance – only sub-program could be changed/modified as needed; Etc