Information Technology 9626/13 May/June 2025: question paper and mark scheme

Mark scheme

1 Max 2 for each method (max two methods): 4 Descriptions must match the method. • Questionnaire (1st) – A remote method of gathering data (1) – Is a fixed set of questions that cannot be changed (1) – Completed in respondent’s own time/location (1) – Can be online or printed on paper//in physical form (1) • Interviews (1st) – The interviewer(s) asks the questions//questions are asked face to face (1) – Answers are gathered in real time (1) – In structured interviews the questions are asked in the same order for each interviewee and with a choice of answers (1) – Unstructured interviews can be different for each interviewee//interviewees can expand on their answers/usually no pre-set list of answers (1) – Interviewer can ask follow-up questions (1) • Data logging (1st) – Uses sensors to collect data (1) – Can be used to collect data over a period of time (1) – Either continuously or at set/regular intervals. (1) • Document analysis (1st) – Examining existing documents (1) to create new information (1)

Mark scheme

2 One mark per bullet point to a maximum of five marks. 5 • SSL stands for Secure Socket Layer and TLS stands for Transport Layer Security (1) • They provide network security (1) • TLS/SSL are used in web browsing/email/Internet faxing/instant Messaging/Voice over IP/VoIP (must have at least two examples) (1) • Client-server applications use TLS in a network to try to prevent Eavesdropping (1) • Encrypts data sent from users to website//data sent from websites to users (1) • Certificates are sent (1) and confirmed with a trusted authority (1) • They enable credit card/online payments to be made securely (1) • SSL/TLS requires a handshake to be carried out. (1) • SSL/TLS is used by the presentation layer//SSL/TLS operate/work between the application layer and the transport layer (1)

Mark scheme

3 One mark per bullet point to a maximum of six marks. 6 • Inference engine compares inputs with rules in the knowledge base (1) • Uses IF …..THEN reasoning (1) Forward chaining • The reasoning uses forward chaining (1) • Forward chaining starts with the available data (1st) – And uses inference rules to extract more data//ask more questions (1) – Until a goal is reached//Until it finds one where the IF statement is known to be true (1) – The THEN part adds new information (1) • Forward chaining can be called data-driven (1) Backward chaining • The reasoning uses backward chaining (1) • Backward chaining starts with a list of goals/hypotheses (1) • Backward chaining would search the inference rules (1st) – Until it finds one which has a THEN part that matches a desired goal (1) • If the IF part of that rule is not known to be true (1st) – The THEN part adds this to the list of goals (1) • Backward chaining can be called goal-driven (1)

Mark scheme

4 Three marks from: 3 • A computer program/code/file/application (1) • It looks like a legitimate computer program/file (1st) – Intended to get victim/target to open them (1) • When program/sw is run, malware is activated (1) • It creates a back door to gain access to a computer (1) • Trojans do not attempt to infect other files/replicate themselves (1) • It can allow the third party to: (any 2 of the following) (1) – Download content onto the computer – Copy data from the computer – Gain control of the computer – Set up a DDOS attack.

Mark scheme

5 One mark per bullet point to a maximum of six marks. 6 Valid/Normal//Data that is from within the acceptable range (1st) • To test that the output is as expected/valid (1) • To test that it is accepted (1) Invalid/Erroneous//Data//Abnormal that is outside of the acceptable range (1st) • Data is of the wrong type/invalid (1) • To test that it is rejected (1) Boundary/Extreme//Data that is at the boundary (of the acceptable range) (1st) • To test that the boundaries are set correctly (1) • To test that the outcome is as expected – accepted and correct output (1)

Mark scheme

6(a) One mark per bullet point to a maximum of two marks. 2 • To indicate time has passed between two scenes in a video (1) • To ease the emotions of the audience after a troubling scene (1) • To create suspense after/before a pivotal/important moment (1) • So that the audience are aware of the end/beginning. (1) • To provide a smooth transition between scenes (1) 6(b) One mark per bullet point to a maximum of two marks. 2 • To provide context • To provide information//better understanding (1) • Identifies author (1) • Identifies sound track (1) • Captions can help viewers engage with your video (1) • Search engines use metadata like captions to understand a video's content (1) • To provide translations (1) • To allow watchers to read what is being said//reason why what is being said may be inaccessible (1) Note This may be combined with “better understanding” to achieve two marks.

Mark scheme

7 Example solution: 8 Count 0 REPEAT INPUT mark IF mark > 70 THEN OUTPUT “You have achieved a Distinction” ENDIF IF mark >= 55 AND <= 70 THEN OUTPUT “You have achieved a Merit” ENDIF IF mark >=40 AND <= 54 THEN OUTPUT “You have achieved a Pass” ENDIF IF mark <40 THEN OUTPUT “You have not reached the Pass mark” ENDIF Count Count+ 1 UNTIL Count = 20 Eight marks from: • Initialise Count before Mark variable is input (1) • REPEAT in correct logical location (1) • Input Mark (1) • Correct Distinction grade criterion//correct fail criterion (1) • Correct Merit grade criterion//correct Pass grade criterion (1) • Correct Increment of Count (1) • Increment of Count is within the loop (1) • UNTIL Count = 20 (1) • UNTIL in correct position (1) • Use of one IF…ENDIF (1) • All OUTPUTs correctly match the criteria (NOT awardable if BP4 or BP5 not awarded) (1)

Mark scheme

8(a) One mark per bullet point to a maximum of four marks. 4 • It operates/controls a device attached to the computer (1) • It provides an interface between operating systems/applications software and the device (1st) – Which handles the translation of requests between a device and the operating system (1) • It allows an operating system to detect/identify the peripheral device (1) • Activates the device when it is needed and deactivates it when it is not needed (1) • Logs and reports errors (1) • Defines where data must be cached (1) 8(b) One mark per bullet point to a maximum of four marks. 4 • Translates a high-level language into machine code (1) • Creates an executable file (1) • Identifies errors in code (1) • Stops interpreting code when an error is found//shows errors as it translates (1) • Errors are dealt with as they are found//immediately (1) • Uses less RAM as only one line at a time is stored/processed (1)

Mark scheme

9 One mark per bullet point to a maximum of five marks. 5 • A vehicle passing over the loop causes a change in inductance (1) • The change in inductance is used to detect the vehicle (1) • The metal in the vehicle causes a change in the magnetic field (1) • The change in the magnetic field causes a current to flow (1) • Loop sends back data which is converted to digital (1) • Computer compares data to pre-set value (1) • If computer detects a change, (1st) – it sends signal to the actuator (1) • The actuator will raise/lower the barrier. (1)

Mark scheme

10(a) One mark per bullet point to a maximum of three marks. 3 • Optimises space on the disk (1) • Files are better organised (1) • Increases reading and writing speeds (1) • Related files are kept together (1) • Files are contiguous (1) • Data retrieval is quicker//files are opened more quickly (1) • Reduces the movement of the read/write heads (1) • Increases longevity/life span of the disk. (1) 10(b) One mark per bullet point to a maximum of three marks. 3 • It can take time to do (1) • It can use a lot of computer memory (1) • It can use a lot of computer processing (1) • It can make the computer less responsive (1) • It can lead to file corruption (1) • The power must be on/uninterrupted throughout the whole process. (1) • Shortens the life of SSDs (1)

Mark scheme

11 Eight marks from: 8 MAX four for 1st marks only Evaluations: E.g.: • Can interrogate/interact with databases to extract data (1st) – So data only has to be typed/entered in once (1) • Can only use the features of the spreadsheet (1st) – Therefore model may be limited (1) • Spreadsheet software may include unneeded features (1st) – Which could be a distraction//which need to be hidden//increase file size (1) • Spreadsheets include formulae//functions (1st) – So complicated calculations can be created more easily (1) – Reduced chance of error (1) • Calculations can be performed more quickly/more easily/recalculated automatically (1st) – so spreadsheet can be used by someone who does not spreadsheet editing skills (1) • What-if statements can be asked/edited (1st) – without rebuilding the model/spreadsheet from scratch each time (1) • Creates graphs (1st) – Which allows data to be more easily interpreted (1) • Graphs that are produced will automatically change (1st) – as new values are added/old values altered (1) • Models/spreadsheets provide objective results (1st) – not affected by user's bias (1) • The use of templates provides consistency over time (1st) – therefore do not need to relearn the model (1) • Valid conclusion drawing together/based on arguments presented in the answer (1)

Mark scheme

12(a) • A composite key is a primary key that uses the contents of two or more 1 fields from a table to create a unique value. (1) 12(b) • A compound key is a primary key that combines more than one foreign 1 key to create a unique value. (1)

Mark scheme

13 Max five marks from: 5 • Add sum = 0 (sum initialisation) (1) • Add count = count +1 (iteration of count) (1) • Replace average calculation from * to / (1) • Reverse Yes/No correctly (1) • Add end shape (1) Corrected flowchart: Start sum = 0 count = 0 Input first number sum = sum + input average = sum / 12 number Display average count = count + 1 Input next number End Yes is count = 12? No