Cambridge A Level Information Technology (from 2017) 9626 — 2024 Oct/Nov Paper 3 · Variant 2

1 JavaScript uses for loops to run through a block of code. (a) In JavaScript, the for loop has the following syntax: for (Statement_1; Statement_2; Statement_3){ // block of code to be executed is written here } Describe the purpose of each of the three statements: Statement_1 ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Statement_2 ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Statement_3 ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... [3] (b) Compare the use of a for loop with a for in loop. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3]

Mark scheme: Question Answer Marks 1(a) Statement_1: 3 One from: • Initialises the counter with a starting value • sets the variable • Is executed (one time) before the execution of the block of code. Statement_2: One from: • Defines the condition for executing the block of code • Is the test statement / tests whether condition is true or not • If condition is true loop starts over/if false loop ends Statement_3: One from: • Counter/value in loop is incremented/decremented • Is the iteration statement • Is executed (every time) after the block of code has been executed. 1(b) Command word: Compare: identify/comment on similarities and/or differences. 3 Three from: Similarities: • Both used to execute/loop through a block of code repeatedly/number of times/over and over/iterate • Both have condition (statements) used (for comparison) when executing the block of code • Both have a limit on the number times the block of code is executed • stops after a set/pre-determined number of times Differences: • For loop used for going through a (sequential) array whereas for in loop is used with objects • For loop creates an integer which is used to index an array/count the number of iterations in order whereas for in loop executes in arbitrary order / not sequential order • For in loop is used for going through the properties of an object to check that the variable is a property of the object.

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2 Describe how the following alterations can be made to parts of a bitmap image, using tools found in image editing software. (a) removing the reflection from eyes in a digital image taken by flash photography ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] (b) making the edges of objects in a digital photograph clearer ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3]

Mark scheme: 2(a) Three from: 3 • Choose / open / import / load the source image in image editing software • Select / use selection tool / rectangle tool on the eyes / part of image // use ellipse selection to select only the eyes / individual eyes • Select / choose from filters / enhances / red eye removal menu • Adjust the parameters / thresholds to set amount of red / colour reduction as required • Select confirm / OK. 2(b) Three from: 3 • Choose / open / import / load the source image in image editing software • Select / use select tool / highlight / use lasso tool on part / whole of image / object • Select / choose from filters / enhances / (un)sharpen / blur mask menu • Set (sharpen) parameters / radius / amount / threshold needed for sharpening / filter (1st) – radius sets the number of pixels from any detected edges that will be sharpened (1) – amount sets how much sharpening is applied to the pixels within the set radius (1) – threshold sets the contrast difference between pixels that is required to detect an edge (1) • Use ‘preview’ option to check the effect • Confirm effect to apply the filter • Use save as to store the file.

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3 A new software application has been evaluated for ease of use. Describe two other evaluations that should be carried out on the new software application. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 3 Six from: 6 Max five from e.g.: • Evaluate for efficiency in use of resources • Monitor / checking / ensuring that code has been optimised for use on different devices • Monitor / checking / ensuring that code uses device memory / storage effectively / efficiently (1st) – avoids memory fragmentation / leakage (1) • Monitor / check to ensure use of network bandwidth is utilised to maximum • Check that it utilises hardware effectively / is compatible with existing hardware • Check that it robust / handles problems / faults sensibly / without losing data Max five from e.g.: • Evaluate how it meets user requirements • Check that it does what the end-users wants / needs it to do • Check that it performs all the functions / tasks / has all the facilities required • Check that there is help available / supporting documentation • Check it is customisable / adaptable by end-users to meet specific needs.

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4 A project to create a new computer game has been divided into the tasks shown in the table. Task Follows on Expected duration Task number from task(s) (weeks) 1 Design the game 6 2 Code the game 1, 4 18 3 Test the game code 2 13 4 Create the user interface for the game 1 12 5 Release the game to the public 3, 7 6 6 Design the documentation for the game 1 6 7 Create the documentation for the game 6 20 (a) Using the information in the table, draw a PERT (Performance Evaluation and Review Technique) chart for the project in the space below: [5] (b) Describe the benefits of using a PERT chart. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3]

Mark scheme: 4(a) Five from: 5 • Correct / appropriate / accepted symbol used for tasks 1 mark • All tasks shown / labelled with name / task number 1 mark • All tasks shown with duration 1 mark • At least 3 tasks correctly linked 1 mark • All tasks correctly linked 1 mark • Task 2 shown dependent on / following both tasks 1 and 4 1 mark An example PERT is: 4(a) Accept alternative symbols for nodes. e.g.: Accept alternative types of PERT charts. 4(b) Three from: 3 • (Clearly) identifies the dependencies between tasks / simultaneous / concurrent tasks • Can show / display / enable calculation of the critical path • Can show / display timing variations in each task • Can enable calculation of float within / whole task • Can help to coordinate / organise tasks within a project.

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5 Discuss the impact of the use of artificial intelligence (AI) in health care. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 5 Eight from: 8 Max one from: • Definition of artificial intelligence e.g. the ability of a computer / machine to perform those activities that are normally thought to require intelligence / ‘machines that perceive their environment and use learning and intelligence to take actions that maximize their chances of achieving defined goals’ Eight from e.g.: Positive: • Rapid diagnostics by expert systems speeds up treatment / remedy so that patient recovers faster / better chance of recovery • Used in data mining / analysis of disease / clinical trial data to find / discover patterns for research into treatments / develop new medicines • Use of AI in robots / therapeutics / social / health assistance technology improves the quality of life for senior citizens / physically challenged individuals • Reduction of errors due to human fatigue so that patient safety / quality of care is better • Used in radiology / tomography to analyse images / data so that detection of disease is better / faster / more accurate / reliable and patient care is enhanced • Used in management of patient data to analyse / find / correlate data in less time • Used to target treatment more precisely / at correct times so that patients can be treated more effectively / to increase recovery rates / probabilities • Used in virtual presence technology / robotic devices to assist in diagnosing diseases remotely so that consultants / surgeons / doctors can monitor / check / examine patients without being present • Used in chatbots to answer patient queries which reduces workload of medical personnel • Used in management of drug dosage / administration to reduce the margins of error in production / delivery / storage • Use in robot-enhanced surgery to assist surgeons to reduce invasion of patient / use in keyhole surgery / decrease recovery times / increase recovery rates • Used in detection of fraud by analysing / data mining claims for medical procedures so costs are reduced / fraudsters are identified. 5 Negative: • Costly / expensive to develop / deploy AI which reduces funds / less money available for other areas of healthcare • Requires expensive / extensive IT / specialist technical support which may reduce funds for medical personnel • AI learns / needs to learn by experience which can affect patient recovery / treatments during the process • Human experts / doctors still required to avoid the misdiagnosis / check diagnosis of unknown / new / unusual diseases because AI does not know / has not met and this can misdirect doctor / take more time • AI may proceed with incorrect procedures in new / unrecognised conditions if it meets conditions / symptoms that it has not met before and this may harm patient • Choice of AI platform / system may be difficult to make / take time and may be difficult to change / amend after implementation.

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6 Using tunneling protocols in networking can affect the security of the data. (a) Explain how tunneling protocols can increase data security. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4] (b) Explain how tunneling protocols can decrease data security. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2]

Mark scheme: 6(a) Four from: 4 • Tunneling protocols used to exchange data between networks across public networks which ensures that the data is kept private • Tunneling protocols encapsulate data by repackaging / wrapping it / TCP / IP packets into a different format which hides the actual type / contents / protocols of the data • Tunneling protocols work at the Link Layer (of protocol suites / OSI model) which hides the actual use of the internet / transport / higher layers / other services from observers / interceptors • Tunnelling protocols used to encrypt payload of other protocols when carried over public networks so target / destination addresses / services / contents are hidden from interceptors / routers / firewalls • Use of SSL (on port 22) / TLS / IPSec / HTTPS to encrypt data / which provides / ensures data security / end-to-end encryption during transmission / exchange. 6(b) Two from: 2 • Can be used to bypass / travel through firewall by hiding / encapsulating protocols that would normally be blocked (1st) – when unwrapped the hidden protocols put data behind the firewall at risk (1) • (Tunneling) connection can be used to make unauthorised connections via ports that are normally blocked by firewalls • Can use different ports to those normally used to third party proxy servers which puts data behind the firewall at risk.

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7 The data mining process consists of several phases. Describe the tasks that occur in each of the following phases in the data mining process. (a) data preparation ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4] (b) evaluation ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4]

Mark scheme: 7(a) Four from: 4 • Selection of the data to be mined with reference to its relevance to the requirements of the client • Selection by reference to quality / technical restrictions e.g. type / quantity / size of data set / number of data sets • Detection and removal of corrupt / inaccurate records in the data sets • Data is ’cleaned’ by removal of irrelevant parts of the data / data set • Creation / construction of new records derived from existing records in the data / data set • Merging data / records with common features / summarising data / aggregating data. 7(b) Four from: 4 • Checks data mining model against the success criteria laid out in the first / business understanding phase • Returns model / creates reports / sends model back to data preparation and / or modelling processes for amendments to be carried out if success criteria not met • Checks against reports / testing outcomes of previous phases to ensure all errors have been addressed / corrected • Creates / produces reports detailing the evaluation process / results / outcomes for client / developers • If success criteria met moves model to deployment phase.

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8 Designers in a company use standalone computer-aided design (CAD) applications to design products. The company has now decided that its designers will change to using a cloud-based CAD application. The company will use parallel running to implement the change. Discuss the use of the parallel running method of implementation in this scenario. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 8 Command word: Discuss: write about issue(s) or topic(s) in depth in a structured way. 8 Eight from: • Both (CAD) applications are run at the same time / simultaneously (1st) – until the new system takes over (1) Advantages: • If the new application / system fails users can fall back on / revert to the old application (1st) – system so data is not lost / work can continue (1) • Considered to be the least / less risky to data compared to other methods of implementation • Staff can learn how to use the system gradually / at a steady pace / learn alongside / while still using old system // properly understand the new system (1st) – so, risks to data / product / designs are reduced (1) • Live data can be used to test the new system so new application / system is tested under real conditions • Both applications / systems can be used and the results / products / drawings compared to identify differences / improvements / faults in new system Disadvantages: • Network / internet infrastructure / access / devices must be available • Designers need to be retrained / learn new skills / method of working / security policies • (More) expensive / costs more time / personnel / resources / financial resources (1st) Max Three from: – because extra / more designers / staff / labour may be needed to run both systems (1) – because more office space / IT systems / power / utilities are needed (1) – specialist / new IT services / technicians needed (1) – cloud-based services are / can be expensive (1) – because designers with IT skills / specialist designers may be in short supply so salaries raised to attract them (1) • Data / products / results from the two applications / systems can be out of synchronisation with each other // compatibility issues between applications • Designers may be lost to other companies / leave the company if they are asked to duplicate their work using two systems • Data / drawings have to be duplicated (1st) – and this can cause errors / mistakes (1) – increase the time taken to produce designs (1)

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9 (a) Explain how each of the following computer animation methods creates the illusion of movement. (i) stop motion ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (ii) key frame ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [3] (b) Describe one property of an object that can be affected by altering its timings in an animated sequence. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1]

Mark scheme: 9(a)(i) Two from: 2 • Each frame is created / drawn / rendered individually / separately • Objects are drawn in (slightly) new position in succeeding frames • 12 / 24 / valid number of frames created for each second of video. 9(a)(ii) Three from: 3 • (Key frame) used to define state / set parameters / set position of objects in the frame at start of sequence • Next / subsequent key frames set new parameters / positions / state of objects in the frame • By user action of dragging / moving / changing colour / size of objects / backgrounds in key frames • (Computer animation) software interpolates / creates intermediate frames / uses tweening to create (natural-looking) flow between key frames • Time between key frames / object position gives illusion of movement (at different speeds). 9(b) One from: 1 • Weight of an object e.g. cricket ball v. balloon when hit / blown • Scale of an object e.g. large object moves slower than small / inertia affects • Emotional state of a character e.g. lethargic / nervous v. alert / excited movements • Provides the illusion / perception of speed • Gives meaning to the movement / motion.

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10 A company is developing a data input screen for entering customer details into a database. Evaluate the use of evolutionary prototyping for developing the data input screen. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 10 Command word: Evaluate: judge or calculate the quality, importance, amount, or value of something. 8 Eight from: Two from: • The system / screen is continually refined and rebuilt (when developed using evolutionary prototyping) • Features not thought of in the requirements and design phase can be added / removed during the development (of the screen) Pros: Max Six from: • Developers and stakeholders engage at all stages / all the time (1) so the delivery of the system is speeded up (1) • The user continuously engages with the system (1), so the new system / screen is more likely to meet the user requirements (1) • Screen / product can be changed at any stage / iteration (1) so can meet / be adapted for changing demands of client / end-user (1) • Continual consultations / interactions between developers / client / end-users (1) results in greater feedback (1) so screen / product is better / of greater quality (1) Cons: Max Six from: • Need to rapidly produce a function-limited prototype (1) reduces analysis time / depth (1) so business risks are increased (1) • Incomplete specifications may be produced (1) so features may be omitted / neglected (1) • Continual need to consult / interact between developers / client / end-users can be costly (1) which raises overall cost of development (1) and can increase the time taken to develop the product (1) • Client may mistake the initial prototype(s) for the finished / final product (1) so all required features may never make it into the final product (1) • Developers may have difficulty knowing when it is necessary to stop ‘tweaking’ / developing the system (1), so the development goes on too long / does not actually finish / product is never finished (1) One mark is available for a valid conclusion / judgement (must have considered both pros and cons).

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