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

1 JavaScript can manipulate and store strings in variables. (a) Define the term string as used in JavaScript. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1] (b) Describe how a string can be created in JavaScript. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1] (c) A variable text1 is used to store Cambridge and a variable text2 is used to store International Examinations in a block of JavaScript code. (i) Describe how the two strings can be joined together (concatenated) as Cambridge International Examinations and stored in a new variable called text3 in a JavaScript statement. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (ii) Describe one method by which the word Examinations can be extracted from text3 for use in another variable. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2]

Mark scheme: Question Answer Marks 1(a) (An object representing) a sequence of (any) characters. 1 1(b) One from: 1 • Enclosing the characters inside quotes • Use of keyword newString to create a string object. 1(c)(i) Two from: 2 • Use the + operator to join the two variables // use of concat() • Use additional + to place a space inside speech marks / quotes / inverted commas / " " in between the two variables • Declare variable text3 • Ensure statement defining the new variable / text3 is placed after the assigning of text1 and text2 • Ensure the statement terminates in a semi-colon / ; Max one for example: • text3 = text1 + " " + text2; OR: use of concat() method i.e.: • text3 = text1.concat(" ", text2); 1(c)(ii) Two from: 2 There are three methods for extracting a part of a string: Marks for: • identifying the keyword of the method • mark for describing that a start point and a corresponding end point/length is used to extract the characters One method, max two per method from: The methods are: • use keyword • slice(start, end) // slice() • substring(start, end) // substring() • substr(start, length) // substr() Allow other methods but syntax must be all correct.

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2 A new stock control system is being tested. Explain how different types of test data are used to test this system. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 2 Six from: 6 Max one for naming at least two from: • Abnormal / invalid / erroneous values • Invalid data format • Normal / valid data • Extreme / boundary data Max six from: • To see what error messages are produced • To test how system deals with unexpected data • To test how the system reacts to valid data / compare with expected results • Null data is used to test how the system reacts to / deals with / processes blank fields • Abnormal / invalid / erroneous values of data is used to test how the system deals with data that is unreasonable / invalid • Invalid data format is used to test how the system deals with / processes data that is not in the expected format • Normal / valid data to test how the system reacts / deals with / processes normal / expected data • Extreme / boundary data to test how the system reacts / deals with / processes data at the boundaries of acceptable data • Live / realistic data to test how the system reacts / deals with / processes actual data from a working system.

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3 Describe what is meant by each of the following terms that refer to bitmap images. (a) brightness ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1] (b) contrast ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1] (c) colour balance ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (d) highlights ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2]

Mark scheme: 3(a) One from: 1 • Degree of pixel intensity • Sum of intensity of red, green and blue pixels (in an image) divided by 3/average of all pixel / colour intensities • Is a relative / perceived quality of the intensity of an image / pixel • Degree of luminosity / light levels • Amount of energy output from a source compared background / another source. 3(b) One from: 1 • The difference between maximum and minimum intensity (of a pixel) / brightest and darkest pixels • Low contrast looks faded / details are hardly perceptible and high-contrast images are sharp / details are easy to perceive. 3(c) Two from: 2 • (Adjustment of) intensities of colours to render neutral / overall / other colours correctly • Primary colours / red, green and blue colours adjusted • White / grey balance used to adjust for different colour casts / artefacts caused by light conditions in (still / video) photography. 3(d) Two from: 2 • (Spots of) light on object when illuminated • With reference to the light source • Used for adjusting overall light levels • Give visual clues (1st) – of shape (of object) (1) – of location (of object) (1).

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4 Colour management systems (CMS) are used in computer graphics. Explain why a CMS is needed. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 4 Six from: 6 • CMS used to ensure that different application / devices / operating systems display colours consistently / predictably • Colour is dependent on the device / monitor displaying the colour(s) • Scanner can produce image with RGB / colour values different from those used by a monitor • Different devices require different colour values sent to them to display the same colours • Colour values need to be transformed / adjusted / calibrated by algorithms / tables / software • Using colour profiles / mathematical representation of the ‘colour space’ of a device (1) not all transformations work for every device in same way (1) • CMS provide choice / selection of tools / algorithms / software to make the transformations • CMS allows re-use of graphics for different media / online and paper (with consistent / predictable colours) • CMS provides automatic / removes need for manual adjustment of colours when using different media / online and paper.

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5 The agile method of software development is to be used to create an app for smartphones. Justify the use of the agile method of software development. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 5 Six from e.g.: 6 • The large software project is broken down into small development cycles called sprints, of e.g. two to four weeks (1) resulting in fast development of usable / working prototype (1) • Customer / client / user gets to see / use a working / minimal featured prototype (1) so can give feedback before the development is advanced / next app features are added (1) • Clear and achievable goals in sprints produce greater motivation / sense of achievement of developer / team workers (1) resulting in a better product (1) • Budgets for short-term / fixed goals / sprints are more predictable (1) resulting in greater control of finances (1) • Increased customer / client / user satisfaction (1) • due to more involvement during development (1) • Faster return-on-investment (ROI) for stakeholders (1st) – due to quicker / earlier (c.f. other methods) releases of app prototypes / iterations (1) • App can be adapted / amended / have features added / removed / improved more easily / quickly / with less work (1st) – in accordance with customer / client / user feedback (1) • App quality is improved (1st) – due to (more) frequent reviews (after each sprint) (1) • Collaboration between team workers / personnel is improved (1st) – due to short development sprints / not having to wait for major decisions to be made / focus on one aspect of app (1)

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6 Ultra-high definition (UHD) television systems have been developed and can be used to watch streaming videos. (a) What is UHD television? ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (b) Describe the impact of the development of UHD television systems on the environment. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4]

Mark scheme: 6(a) Two from e.g.: 2 • Digital TV format with aspect ratio 16:9/widescreen • Horizontal screen resolution of c.4000 (4K UHD)/8000 (8K UHD) pixels • Increased (v. HD) dynamic range/colour space/gamut • Incorporates surround sound/22.1 audio system. 6(b) Four from e.g.: 4 • Increased carbon emissions c.f. SD screens during production • Increase in production of (potent) ‘greenhouse gases’ / nitrogen trifluoride during manufacture of flat screen / OLED / LED / LCD screens • Increase in redundant / discarded devices / TV sets / routers (as users upgrade) into landfill • Increase in pollution levels from discarded / leaching of components / chemicals from discarded devices / TVs / routers • Increase in power demand by TV set / communications systems during use • Increase in carbon emissions (up to x10 c.f. SD) during when used for streaming video in HD / UHD • Increase in environmental disturbance (e.g. more construction) to provide necessary infrastructure • Increase in bandwidth required for UHD (note for STM (rec. min bandwidth is 22 to 23 Mbit/s) so need more power / replacement fibre/routers.

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7 System flowcharts are a visual representation of the flow of data in a system. (a) State the use of each of the following symbols in a system flowchart. (i) ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [1] (ii) ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [1] (b) Draw one other system flowchart symbol and describe how it is used. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2]

Mark scheme: 7(a)(i) 1 (To represent the) output of multiple documents. 7(a)(ii) 1 (To represent a) magnetic disk file. 7(b) One symbol from: 2 Two marks awarded for: • drawing of system flowchart symbol 1 mark • description of drawn symbol 1 mark Description must tally with drawing for second mark. These are from the syllabus: Allow other valid alternative symbols.

8 Data mining is used by businesses to analyse very large quantities of data. Discuss the use of data mining by businesses. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 8 Command word: Discuss: write about issue(s) or topic(s) in depth in a structured way. 8 Eight from e.g.: • Data mining allows businesses to collect reliable information for use in marketing research (1) to determine the products that interest customers (1) and then make those products available (1) • Helps businesses find patterns in their data (1) to evaluate their own policies and procedures for effectiveness (1) • Can be used to find correlations between products/consumers/suppliers (1) to help identify trends that might not have been previously identified before (1) to help make more accurate predictions/target marketing (1) to help make informed decisions/better decision-making based on trends within large quantities of data (1) • Can be used to detect fraud/risks (1) that may not be apparent through traditional data analysis (1) • Can be used to discover trends/patterns in customer buying habits (1) which can be used to suggest products/advertise/target products at specific demographics (1) • Data mining tools are complex/difficult to use (1) so specialised staff are required/needs to be outsourced (1) which increases costs/can be expensive (1) • Inaccurate information may be produced (1) where data is incomplete/from inaccurate sources (1) resulting in inaccurate predictions/poor decisions being made (1) • Privacy of individuals cannot be guaranteed/data may not be completely anonymised (1) so personal/private data of individuals may be exposed/individuals may be identified (1) • Accuracy/effectiveness dependent on size of databases (1) so businesses have to share data with others (1) • Can be expensive and costs may exceed the benefits/increased profits for some/small businesses.

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9 Explain the drawbacks to a business of using social media for advertising their products. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 9 Six from e.g.: 6 • Requires extensive research into target audiences which increases costs • Targeting wrong audience reduces sales / lowers brand awareness • Requires uses of different / numerous social media platforms with customised advertising to target different / reach all audiences which can increase costs • Results of marketing need to be followed up / analysed to justify costs of social media marketing campaigns and this can be costly • Can be costly for small businesses due to need to advertise on multiple platforms / ROI can be low • Negative feedback can spread quickly which can reduce sales / cause resistance to product • Negative feedback cannot easily be removed / stays visible to all customers / is difficult to refute • Lack of engagement / failure to respond can lead to negative feedback that damages company reputation • Poor / inadequate / insensitive / inappropriate response can be seen by all and damage company image • Security of information depends on social media platform policies / actions / company data may not be secure • Company data / information may be used / sold by the social media platforms • Depends on availability of mobile communications / internet access / can only reach those with access.

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10 (a) Describe what is meant by CGI in animation. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (b) (i) Describe cel animation. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (ii) Cel animation is rarely used to create animations. Explain why computer software has replaced cel animation. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2]

Mark scheme: 10(a) Two from: 2 • Computer generated imagery // images that are created by computers • For use in movies / TV programmes / commercials / games / simulators / art / printed media • 2D / 3D objects that can be animated / appear to move • Text / figures / objects / spaces / environments / background in which action is set • Create special effects / SFX. 10(b)(i) Two from: 2 • Manually painting images onto celluloid sheets • (Painting many images) each with a small amount of movement of objects • Photographing each individual cel on to film / video • Displaying each cel in sequence to produce illusion of movement. 10(b)(ii) Two from: 2 • Can reduce costs because (computer software / application has) replaced skilled / large teams of animators • (Computer software / application) can create sequences / complete animations in shorter time than hand-drawing • (Computer software / application) uses key frames can create sequences / complete animations with greater accuracy / realism of movements • Animations are always / already digital so (digital) photography is not required removing errors / inconsistences in images / cels.

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11 Unauthorised access to computer files can result in the manipulation and modification of computer data. (a) Describe the difference between data manipulation and data modification. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] Please turn over for Question 11(b). (b) Evaluate the use of software methods in helping to prevent unauthorised access to computer data and files. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [8]

Mark scheme: 11(a) Two from: 2 Max one from: Data manipulation: • Changes appearance / format / layout but not the factual content of the data • Data manipulation is where logic / calculation is applied to give new data / information / results Max one from: Data modification: • Changes the factual content of (saved / stored) data / changed to have a different value • Data that is manipulated and then stored in the same place. 11(b) Command word: Evaluate judge or calculate the quality, importance, amount, or value of something. 8 Eight from: Max six from: Biometrics: • Use of biometrics / biometric authentication (1) for identification of user / access control (1) so that user can be uniquely identified (1) • Use of unique characteristics of individual such as iris patterns, fingerprints, face / hand geometry, movement (e.g. movement of mouse) stored as digital data (1) which can be compared with user during identification (1), but these must be measurable and easy / quick to check (1) • (Biometrics) are difficult to copy / forge / assign to others (1) so provide a high level of security (1) cannot be assigned to / used by others (1) • (Use of biometrics) can invade individual privacy (1) so may not be welcome in workplace / meet with resistance from public (1) Max six from: Encryption: • Use of encryption (1) scrambles data using a secret key / encryption code (1) so that it cannot be understood (1) so provides privacy / secrecy for the data (1) • Data can only be understood by those who have the key to decrypt the data (1) so can restrict the data to only those authorised to have access to it (1) • Encryption does not prevent data from being deleted (1) so data can still be lost (1) Max six from: Access rights / permissions: • Use of access rights / permissions (1) to control who has the right to access file (1) and can be at user level / individual users (1) so unauthorised users can be refused access to file (1) • Use of access control lists on individual files (1) specify which users / system resources can access file (1) • Can restrict access to specific devices (1) preventing unauthorised users from using own devices (1) Max six from: Anti-malware / anti-virus software: • Use of anti-malware / anti-virus software (1) to scan in real-time incoming files (1) to prevent installation of malware (1) that may delete / amend / modify / steal data / files (1) • Can scan stored files (1) to check for / remove malware (1) that may delete / amend / modify / steal data / files (1) • Must be regularly updated (1) to protect against evolving / new threats (1) 11(b) Max six from: Anti-spyware software: • Use of anti-spyware software (1) to scan activities in real-time (1) to block / remove spyware to prevent data being collected for / sent to third parties / unauthorised users (1) • Monitor (in real-time) network traffic (1) for indications / signs of spyware activity (1) to prevent data being stolen / accessed by unauthorised users (1) • Must be regularly updated (1) to protect against evolving / new threats from spyware (1) one mark is available for a valid conclusion / judgement.

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