Information Technology 9626/33 May/June 2025: question paper and mark scheme

Mark scheme

1(a) TWO from: 2 • create connection between (virtual) terminal and remote host • can allow unrestricted access to system • for network diagnosis / valid example of Telnet use 1(b) THREE from: 3 • create a connection allowing packets from one network to travel across another / different (protocol) network • connects to another network without packets being examined / altered / recognised in any way • connect two IP LANs that use different protocols • support VPNs for a data connection / link between devices • used to overcome restrictions on networks / use of forbidden protocol / wrap packets inside packets of allowed protocols so they can travel on the network 1(c) THREE from: 3 • send packets by connection-less method • used where error-checking of packets is not necessary / not done • used by DHCP clients / servers to exchange network details • Used for streaming services • Used by routers exchanging routing data – the simple network management protocol (SNMP) • used by using the domain name system (DNS) when looking up IP addresses / domain names

Mark scheme

2(a) THREE from: 3 • The objectives are identified • The required resources are identified / documented • The success criteria are determined / agreed / quantified • The stakeholders are identified / agreed • Needs of stakeholders established • The project scope is determined / carried out / scoped • Determining milestones • Determining deliverables • Determining required resources • Developing high-level schedules 2(b) FOUR from: 4 • To check that building / final product has been created / delivered to client • To check that nothing has been overlooked / that project is complete • To check against acceptance criteria / success criteria • To check product / building is in satisfactory condition • To check / ensure that project has ended / is finished (1st) – all client / parties / stakeholders agree (1) – so that no more amendments / additions / changes can be made (1)

Mark scheme

3 SIX from: 6 • Describes the new system • Describes how it meets the user requirements • Defines the features / functions of the new system • Specifies how new system interfaces with old / remaining systems • Defines the behaviour of the new system • Describes the data to be used by the system • Specifies how the new system resolves / attempts to resolve any problems found in the old system • Defines / describes the operating system to be used / required for the new system • Specifies the hardware to be used / required for the new system • Specifies the software requirements for the new system • Specifies the maintenance / upgrades required • Describes the types of end-users of the new system • Specifies the access rights of each type of end-user • Used as a basis of the design specification

Mark scheme

4 Command word: Justify - support a case with evidence / argument. 6 SIX from, e.g.: • Saves time when creating large numbers of multiple personised documents • Only need to create one master document • Only need to create / keep / maintain one data source • Letters / emails and addresses automatically compiled and sent • Only need to edit / update the master / source documents • Less documents to (error) check / proofread • Documents are personised (to individual customers) • Reduces risk of errors / typos / incorrect information / missing information • Reduces possibility of personal details going to other / wrong customers • Ensures use of company style on all documents sent out • Consistent layout / format of document

Mark scheme

5(a) ONE from: 1 • a cryptographic hash of the previous block • a timestamp • (all the) transaction data 5(b) TWO from, e.g.: 2 • (As a distributed ledger) in cryptocurrency • Smart contracts • Storing medical records

Mark scheme

6(a) TWO from: 2 • The data is in a different original format to that required (by the software used for analysis) • The data structure of the data is different to that required (by the software used for analysis) • The data type of the data is different to that required (by the software used for analysis) • To make the data compatible with other data (that is being analysed) • To anonymise data / remove data that can identify individuals • To add other data e.g. timestamps to it • To allow it to be moved to another system 6(b) FOUR from: 4 • Use of both specialist / manual methods of checking the data • Anomalies / outliers are identified / removed • Inaccuracies are corrected • Duplicate data is removed • Irrelevant data is removed • Out-dated data is removed • Inconsistencies are removed / reconciled e.g. names are spelled the same throughout • Contradictions are removed • Ensure that the same unit of measurements are used throughout • Correct structural errors • Deal with missing data

Mark scheme

7 Command word: Evaluate: judge or calculate the quality, importance, amount, 8 or value of something. EIGHT from: All types of compression: • (All) compressed images have a lower bit rate / number of bits (than the original uncompressed image) • (So, there are fewer bits) to transfer in a set unit of time / one second / (complete) image is transferred in a shorter time • Fewer bits to store (on HDD / SSD / storage medium) • Less storage space is needed / more storage space available for other images / files • (Compression) reduces the file size • (Can be) loss / detail of information about the image • Can / may remove image metadata Lossless: • Lossless compression removes unnecessary / repeated data (1st) ○ has little / no effect on visual appearance of image / original image can be (perfectly) restored / no loss of quality (1) • Lossless compression can / may store extra image data / index of image data (1st) ○ so, reduction in size may not be as much as expected / may not be worthwhile (1) Lossy: • Lossy compression permanently removes data (1st) ○ data cannot be restored (1) ○ original image cannot be (perfectly) restored (1) • Loss of resolution of detail / reduction of the number of colours / reduction colour depth (1st) ○ quality of image is reduced / less vibrant / less detailed / ‘blocky’ / pixelated (1) ○ and have a significant visual impact on an image (1) • Repeated use of lossy compression / opening / saving during editing results in degraded image (1st) – compression artefacts can be introduced (1) – valid example e.g. halos, banding, striping (1) – unrealistic appearance of photographic images / unusable images (1) Conclusion: • One mark for a reasoned conclusion

Mark scheme

8 SIX from: 6 Max FIVE from: Advantages: • No need to carry cash (1st) – so, risk of loss / theft of money is reduced (1) – security is higher (1) • (mobile) app can hold all required information (1st) – so easily / quickly used when mobile / in a hurry (1) • Money transfer is (usually) faster than when using back transfers / credit cards / cheques • Recipient gets payment quicker / transactions completed faster • Not tracked by banking system / regulators • No need to exchange currencies / visit money exchange • Avoid additional bank / exchange charges • Automatically calculates into home currency Max FIVE from: Disadvantages: • If error in transaction / money sent to wrong recipient refunds / reversal of transaction not possible • Requires regular checking of balance to ensure sufficient funds stored • Needs regular top-ups to allow payments / avoid refusal of transaction • Some transactions can take several days to appear / funds made available • Banks cannot monitor transactions • Can be used for illegal transactions • Need an internet connection to reconcile payments

Mark scheme

9 SIX from: 6 • Security of bank / customer data is not under direct control of bank • Privacy of customer details not under direct control of bank • Privacy / security is dependent on the cloud provider • Bank has less control over infra-structure (1st) – limited flexibility over functions (1) – no control over where data is stored (1) – may have to comply with data regulations of several countries (1) • Locked in to / tied to third-party supplier (1st) – difficult to change suppliers / move services to another supplier (1) – if supplier fails / goes out of business (1) – can lose bank’s data (1) • More vulnerable to cyber-attacks than office-based / non-internet connected services

Mark scheme

10 Command word: Justify: support a case with evidence / argument. 6 SIX from: VPNs can: • use encryption • to provide security of data • increased privacy • Provide protection against data analysis (1st) ○ by service providers (1) ○ valid example analysis of e.g.: email, web browsing (1) • Provide protection against adjustment of bandwidth / throttling of data streams / video streams (1st) ○ by service providers / network administrators • Can connect geographically distant company LANs • Less expensive than owning / renting / leasing connections / own network • No need for IT specialists to maintain own external network • (Can be used to) circumvent / defeat / avoid local geographical restrictions (1st) – on content e.g. video streams / live sporting events (1) – on services e.g. social media sites / services / news services (1)

Mark scheme

11(a) FIVE from: 5 e.g.: • Reduced / little waste of raw materials so fewer scarce resources used • Can make use of eco-friendly plastic / corn-based plastics – to reduce long-term pollution / persistence of materials • Fewer components in objects • Ability to make hollow / odd-shaped parts • Can use less energy / raw materials used in making parts • Can create scarce spare parts (1st) – so products / appliances can last longer (1) • Products can be printed / manufactured on demand / no need to make / store huge inventory • Products can be manufactured where required reducing transportation costs / fuel use 11(b) THREE from: 3 e.g.: • Can require a lot of energy to produce / print items • large carbon footprint (1st) – adds to global warming (1) • Uses plastic materials (to print) (1st) – adds to amount of durable / non-degradable / pollution by plastic in environment (1) • Plastics made from oil / fossil fuels • Increased greenhouse gases • Produces fumes with toxic by-products / airborne particles (1st) – irritating to the eyes / nose / cause injury to organs (1) – Increased (micro-)plastic in body (1)