Cambridge A Level Information Technology (from 2017) 9626 — 2022 May/June Paper 1 · Variant 2

This document has 12 pages. Any blank pages are indicated. [Turn over Cambridge International AS & A Level INFORMATION TECHNOLOGY 9626/12 Paper 1 Theory May/June 2022 1 hour 45 minutes You must answer on the question paper. No additional materials are needed. INSTRUCTIONS ● Answer all questions. ● Use a black or dark blue pen. ● Write your name, centre number and candidate number in the boxes at the top of the page. ● Write your answer to each question in the space provided. ● Do not use an erasable pen or correction fluid. ● Do not write on any bar codes. ● You may use an HB pencil for any diagrams, graphs or rough working. ● Calculators must not be used in this paper. INFORMATION ● The total mark for this paper is 70. ● The number of marks for each question or part question is shown in brackets [ ]. DC (LK/CB) 303907/2 © UCLES 2022 * 5 3 6 5 1 2 1 4 7 3 *

2 9626/12/M/J/22 © UCLES 2022 1 Some students have been asked by their teacher to carry out a study. They will collect data about the families living in five streets close to their school. They will carry out the study using direct data sources and will not use records from the 2020 census which are kept at the city hall. Describe the suitability of using direct data sources rather than the census data for the study. … … … … … … … … … … … … [5] 2 Encryption has many uses, including the encryption of hard disks. Describe hard disk encryption. … … … … … … … … … … [4]

3 9626/12/M/J/22 © UCLES 2022 [Turn over 3 Julia is setting up a hairdressing business. She has recruited several staff. She is creating a database of all her staff and has written down all their details ready for entering into a computer. She will need to verify the data when it is entered. She has been told that she cannot use a parity check but should use visual verification and double data entry. (a) By describing what is meant by a parity check, explain why it might not be suitable in this scenario. … … … … … … … … … … [4] (b) Compare the similarities and differences between the visual checking and double data entry methods of verification. … … … … … … … … … … [4]

4 9626/12/M/J/22 © UCLES 2022 4 The performance of mainframe computers and supercomputers is often measured using performance metrics. Compare, by describing the similarities and differences between them, the different types of performance metrics. … … … … … … … … … … … … … … [6]

5 9626/12/M/J/22 © UCLES 2022 [Turn over 5 When a high level language program is written, it has to be translated so the computer can run it. This can be achieved using a compiler or an interpreter. Discuss the advantages and disadvantages of using a compiler rather than an interpreter. … … … … … … … … … … … … … … … … … … … … [8]

6 9626/12/M/J/22 © UCLES 2022 6 Sensors are used in monitoring systems to measure physical variables. It is important that sensors are calibrated before use. (a) Describe, in detail, these sensors and give an appropriate use for each. Each use must be different. Humidity … … … … … Sound … … … … … [4] (b) Explain the importance of calibration. … … … … … … [2]

7 9626/12/M/J/22 © UCLES 2022 [Turn over (c) Describe the differences between one point calibration and two point calibration. … … … … … … … … … … … … [5]

8 9626/12/M/J/22 © UCLES 2022 7 Josefine has started to draw a flowchart which inputs 10 numbers and outputs the largest value. Complete the flowchart by filling in the empty boxes and by placing yes and no as appropriate in the diagram. Start Stop count 0 max 0 Input number [7]

9 9626/12/M/J/22 © UCLES 2022 [Turn over 8 Pharming is a method used by hackers to obtain information from bank customers. (a) Explain what is meant by pharming. … … … … … … … … … … [4] (b) Describe three methods a customer could use to minimise the risk of becoming a victim of pharming. … … … … … … … … [3]

10 9626/12/M/J/22 © UCLES 2022 9 Many companies use computers to process their payroll. A transaction file is produced once a week. It consists of the WorkerID and HoursWorked fields. The master file contains the WorkerID, RateOfPay and WagesSoFar fields as well as other details. The WagesSoFar field represents how much each worker has earned so far this year. Each worker’s wage is calculated by multiplying the HoursWorked by the RateOfPay. When the wage for that week is calculated, it is added on to the WagesSoFar field. Every week the master file has to be updated to include the new wage earned so far this year. (a) Complete the following pseudocode algorithm which shows the process of updating the master file. You can assume no other transactions are being carried out. READ first record in transaction file READ first record in old master file WHILE not end of transaction file IF transaction file WorkerID = master file WorkerID THEN … … … … … … … … … … … … … … [6]

11 9626/12/M/J/22 © UCLES 2022 (b) Updating a master file in a payroll system is an example of batch processing. Discuss the advantages and disadvantages of using batch processing, compared to other types of processing, for a payroll system. … … … … … … … … … … … … … … … … … … … … [8]

12 9626/12/M/J/22 © UCLES 2022 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Cambridge Assessment International Education is part of Cambridge Assessment. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. BLANK PAGE

This document consists of 11 printed pages. © UCLES 2022 [Turn over Cambridge International AS & A Level INFORMATION TECHNOLOGY 9626/12 Paper 1 Theory May/June 2022 MARK SCHEME Maximum Mark: 70 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge International will not enter into discussions about these mark schemes. Cambridge International is publishing the mark schemes for the May/June 2022 series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components.

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 2 of 11 Generic Marking Principles These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these marking principles. GENERIC MARKING PRINCIPLE 1: Marks must be awarded in line with: • the specific content of the mark scheme or the generic level descriptors for the question • the specific skills defined in the mark scheme or in the generic level descriptors for the question • the standard of response required by a candidate as exemplified by the standardisation scripts. GENERIC MARKING PRINCIPLE 2: Marks awarded are always whole marks (not half marks, or other fractions). GENERIC MARKING PRINCIPLE 3: Marks must be awarded positively: • marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate • marks are awarded when candidates clearly demonstrate what they know and can do • marks are not deducted for errors • marks are not deducted for omissions • answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the question as indicated by the mark scheme. The meaning, however, should be unambiguous. GENERIC MARKING PRINCIPLE 4: Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level descriptors. GENERIC MARKING PRINCIPLE 5: Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may be limited according to the quality of the candidate responses seen). GENERIC MARKING PRINCIPLE 6: Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or grade descriptors in mind.

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 3 of 11 Question Answer Marks 1 Five from: By interviewing the family, the students will obtain up to date information/census is two years old/census data may be out of date More/detailed information will be obtained as the census may not contain all the information required/has limited information/fewer details They are able to collect only as much information as they require/the census may include information they do not need … …might take time to filter extra information out It may be cheaper to visit the streets than the school paying transport costs to get the students to city hall It may be too time consuming to collect direct data / to go to every house in these streets / only need to make one trip to city hall The study might be limited as it is only five streets/the census would allow them to extend the survey Residents might not be at home when the students call/nobody at home would not be a problem with the census Data may take time to collate and present in a meaningful way/census data is already collated and presented so it is easier to find the required information 5 Question Answer Marks 2 Four from: When a file is written to the disk, it can be automatically encrypted by encryption software Full disk encryption is when the data is encrypted as soon as it is saved to the hard disk When a file is read from the disk the decryption/encryption key/password is needed to decrypt it When a file is read from the disk, the software automatically decrypts it… … while in some types of hard disk encryption leaving all other data on the disk encrypted (All) the files on the disk are encrypted/ It’s the encryption of data on that disk… …except in some cases the operating system Whether the disk stays in the computer or moved to another computer it is still encrypted Only the person/computer with the secret/decryption/encryption key/password can understand the data on the disk/data can’t be read without the decryption/encryption key/unauthorised people cannot read the data 4

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 4 of 11 Question Answer Marks 3(a) Four from: For even parity: Three max from When data is transmitted the sending device/computer counts the number of ones in each byte Each byte is checked individually The parity bit is used to make sure the number of ones is even If the number of ones is even it sets the parity bit to 0 (and adds this on to the end of the byte) If the number of ones is odd it sets the parity bit to 1 (before adding it on) Every byte of data should have an even number of ones The receiving device/computer checks each byte to make sure that it has an even number of ones If the number of ones is odd there has been an error during the transfer of data Two max from In this example data is not being transferred from one device to another/data is not being transmitted She is only entering data to the computer so will need to use an alternative verification method Accept answers which are odd parity answers (substitute odd for even in points above) 4 3(b) Four from Similarities Both involve comparing data that has been/is being entered with another copy Both involve checking that data has been entered correctly not that it is correct/pick up errors made during data entry Differences Visual verification is carried out by a human/user/yourself Double data entry is carried out by the computer/ computerised Visual verification involves comparing the entered data with the original source Double data entry involves comparing two versions of the entered data Visual verification will enable the user to see mistakes if they have been made With double data entry computer will alert user to the fact that a mistake has been made and they decide which version has been copied correctly/freezes keyboard to prevent data being entered until error is corrected Must have at least one similarity and one difference to gain full marks 4

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 5 of 11 Question Answer Marks 4 Six from: Similarities Both are used to measure performance speeds of computers/processors Both can be unreliable as the complexity of instructions can vary according to which benchmark program/test is used/complex instruction takes longer to process than a simple one Differences MIPS are used with mainframes (M)FLOPS used with supercomputers MIPS can be used with integers (M)FLOPS with real/floating point numbers MIPS measured in millions (M)FLOPS measured in quadrillions and higher MIPs is millions of instructions per second, FLOPs is floating point operations per second (must have both) MIPS used when measuring performance of computers involved in running application software… …whereas FLOPS used where scientific/complex calculations need to be carried out MIPS do not take into account input/output speeds… … whereas FLOPS do not take into account CPU’s clock speed , bus speed, the amount of RAM available Must have at least one similarity and difference to gain full marks 6

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 6 of 11 Question Answer Marks 5 Eight from: Advantages Once it is compiled a program does not have to be translated again A compiled program can run faster than interpreted software Compiling a program is a much quicker process /translates it faster than interpreting… … as whole program is translated all in one go /all at once … …unlike interpreter translates one line at a time Once the program is already compiled into machine language, there is no translation software that the user has to keep up to date Compilers also improve security for programmers… …makes it much harder to copy code/machine code is difficult to understand and alter… …so fewer risks of copyright infringement… … with an interpreted program, the source code can always be seen so greater risk of software copyright infringement Disadvantages Can only be used on one operating system … source code can be interpreted on any operating system provided interpreter is present… …will need to use an interpreter if program is to be shared… It is slow/(more) difficult to debug the program/find errors… …the whole program needs to be compiled again after an error is corrected… …error messages are output at the end… …whereas with an interpreter error messages are output as they are found It uses up more memory than an interpreter… …as whole program has to be loaded… …interpreter only requires a few statements of the program to be in memory Unlike an interpreter, does not allow small pieces of code to be tested to make sure they work before continuing with the rest of the program More likely to crash the computer as it is running directly on the CPU Must have at least two of each to gain full marks Must be a proper discussion to obtain full marks Max. six marks if bullets/list of points Must have expansions or comparisons to be a proper discussion 8

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 7 of 11 Question Answer Marks 6(a) Humidity sensor combination of moisture sensor and temperature sensor/measures how much moisture is in atmosphere together with temperature – 1 mark Used in weather stations to measure relative/absolute humidity /air humidity /any suitable example – 1 mark Sound sensor converts sound waves into voltages/electrical signals – 1 mark Used in environment monitoring systems to measure noise pollution /any suitable example – 1 mark 4 6(b) Two from: The accuracy of all sensors reduces after a period of time... ...due to constant use in/exposure to the atmosphere/liquids that are being used Regular calibration helps to maintain the accuracy of the sensors/helps to make sure sensors produce accurate/correct/reliable readings Other devices within a monitoring system may deteriorate over time resulting in a need for recalibration 2 6(c) Five from: Only one measurement point/reading with one point calibration whereas with two point calibration at least two readings are taken One point calibration is appropriate for sensors used to measure a value that is constant/never changes… …whereas two-point calibration is used with sensors that measure a constantly changing variable With one point calibration the offset only is calculated/ the sensor reading is subtracted from the known value only… …the offset is then added to every subsequent reading With two point calibration sensitivity needs to be included not just an offset Two point calibration is used where there is a linear relationship between the two readings The slope of the line connecting the two readings is compared with the slope of the line of the pre-calibrated sensor/the range values of the sensor is compared with the range values for the standard Two point calibration compensates for both offset errors and sensitivity/slope errors 5

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 8 of 11 Question Answer Marks 7 Is number <= max in 1st decision box – 1 mark Yes/no in correct positions at 1st decision box – 1 mark max ← number in correct box – 1 mark increment count in correct box – 1 mark is count = 10? in 2nd decision box – 1 mark yes/no in correct positions at 2nd decision box – 1 mark Print max in correct box – 1 mark 7 Start count ← 0 max ← 0 yes yes Input number Is number <= max? no max ← number count ← count + 1 Is count = 10? no Print max Stop

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 9 of 11 Question Answer Marks 8(a) Four from: Hacker creates a fake website which looks like the actual bank’s website/legitimate-looking website Fools the user into thinking they have gone to the correct website/have not been re-directed Hacker installs a piece of malicious software/code on customer’s computer/ user downloads a piece of malicious software/code without realising it Software corrupts the Hosts file on the user’s computer Software adds the URLs of banks together with IP address of the fake website Fraudster redirects genuine website’s traffic to own website/ when user enters a bank’s URL they are redirected to hacker’s website … …user is now sending personal details to fraudster’s website unknowingly / website asks customer to enter banking information/hacker gains personal information from website /customer types in personal details on website Hacker uses the acquired information from the website to log on to the user’s bank account/make purchases/commit identity theft/withdraw cash 4 8(b) Three from: Use up to date anti-virus software to prevent the downloading of malicious software Use firewalls to prevent malicious software entering the computer Use trusted DNS servers / don’t enter personal data into sites without https The latest browsers alert users when a fake website has been loaded/users need to use the latest browser software updates Use a trusted, legitimate Internet Service Provider Check the digital certificate to make sure the site is legitimate Be suspicious and careful not to use websites which contain poor grammar or spelling Avoid using public Wi-fi systems 3

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 10 of 11 Question Answer Marks 9(a) READ first record in transaction file READ first record in old master file WHILE not end of transaction file IF transaction file WorkerID = master file WorkerID THEN WagesSoFar ← WagesSoFar + (RateOfPay*HoursWorked) WRITE updated master file record to new master file READ next record in transaction file ENDIF READ next record in master file ENDWHILE Six from: Correct calculation – RateOfPay*HoursWorked - 1 mark Correct calculation - WagesSoFar ← WagesSoFar + (RateOfPay*HoursWorked) – 1 mark Correct update – 1 mark Read next transaction file record… – 1 mark …immediately before ENDIF – 1 mark ENDIF– 1 mark Read next master file record… – 1 mark … immediately after ENDIF – 1 mark ENDWHILE at end of algorithm – 1 mark 6

9626/12 Cambridge International AS & A Level – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 11 of 11 Question Answer Marks 9(b) Eight from: Advantages Batch processing does not require constant use of the computer when it might be needed for other tasks... ...the payroll only needs to be run at the end of the week/month… …whereas real time processing would require computer to be available all the time… …batch processing/payroll can be run at convenient times for the company/when the computing resources are less busy/when there is little demand for computer resources/can be run overnight Real-time processing requires immediate processing of data which is unnecessary with payroll... ...as hours worked would only be known at the end of each day so no point in using real-time processing Real-time processing is not usually capable of processing large volumes of data such as running a payroll whereas batch processing is Batch processing systems only need lower specification computers… …whereas real-time processing needs more complex computer systems Online processing requires more hardware making it more expensive than batch processing Batch processing only needs a few employees to enter the data… …so total wage bill is less… …whereas online processing systems can need employees to be constantly using the system In batch processing systems there are fewer/no transcription/update/data errors… …than human operators would produce in an online system Disadvantages With batch processing there is a time delay between collecting the input data and getting an output/data is not processed until the time specified With batch processing the information is only up to date after the master file has been updated by the transaction file… …whereas in real-time processing information is always up to date With batch processing systems errors are only revealed during processing/after batch process is complete which can be overnight and so cause delays/errors cannot be corrected until the batch process is complete… …in online processing errors are revealed, and can be acted upon, immediately Users cannot terminate a process during execution/have to wait until execution is completed Must have at least two of each to gain full marks Must be a proper discussion to obtain full marks Max. six marks if bullets/list of points Must have expansions or comparisons to be a proper discussion 8