Software Engineering · Quiz 2 · Jan 2026

**1. Identify the distinction:** The feature is already released; diagnosing and patching a browser-specific problem is post-release maintenance. **Answer: D — Maintenance.** A: **Incorrect:** Initial design precedes the released system. B: **Incorrect:** Although code is changed, its lifecycle purpose is post-release maintenance. C: **Incorrect:** Testing may support the patch, but the overall activity is maintenance. D: **Correct:** Post-release fixes and adaptations belong to maintenance.

**1. Identify the distinction:** An agreed interface defines parameter names, types and allowed interactions between modules. Preserving that contract prevents one developer’s incompatible parameter change from breaking another module. **Answer: B — Interface definition.** A: **Incorrect:** Unit tests may detect breakage but do not alone define a shared contract. B: **Correct:** A stable, explicit interface establishes the intermodule contract. C: **Incorrect:** Acceptance tests address user-level requirements. D: **Incorrect:** Refactoring does not itself prevent breaking an undocumented interface.

**1. Identify the distinction:** Individual functions are tested in isolation from other components. This is unit testing. **Answer: C — Unit testing.** A: **Incorrect:** Integration testing exercises interactions between units. B: **Incorrect:** Acceptance testing verifies the product against customer requirements. C: **Correct:** The scope is isolated program units. D: **Incorrect:** Beta testing uses external users in real-world conditions.

**1. Identify the distinction:** Coding begins without a systematic specification and is followed by repeated fixes to make the product fit expectations. This is build-and-fix programming. **Answer: A — Build-and-fix programming.** A: **Correct:** The approach builds first and fixes mismatches reactively. B: **Incorrect:** Waterfall follows defined sequential lifecycle phases. C: **Incorrect:** Spiral explicitly iterates through risk analysis and planning. D: **Incorrect:** A prototype model deliberately builds a feedback artifact to refine requirements.

**1. Identify the distinction:** A standardized questionnaire collects well-defined answers from many geographically dispersed respondents with low per-person effort. **Answer: D — Questionnaires.** A: **Incorrect:** Individual interviews are costly at this scale. B: **Incorrect:** Focus groups engage small groups rather than thousands efficiently. C: **Incorrect:** Observation is poorly suited to collecting many specific answers remotely. D: **Correct:** Questionnaires scale to standardized, geographically distributed responses.

**1. Identify the distinction:** The user-story form is “As a [role], I want [feature], so that [benefit].” It identifies who needs what and why. **Answer: C — Role–Feature–Benefit.** A: **Incorrect:** Time is not the third component of the usual user-story form. B: **Incorrect:** This describes processing rather than the role and business benefit. C: **Correct:** The sequence is role, feature and benefit. D: **Incorrect:** Module and deadline do not replace the user and benefit.

**1. Identify the distinction:** Reusing saved details reduces repeated entry, time and effort for returning customers. That primarily improves efficiency. **Answer: B — Efficiency.** A: **Incorrect:** Effectiveness concerns successfully achieving the goal, not primarily reducing effort. B: **Correct:** The same purchase can be completed with fewer actions and less time. C: **Incorrect:** Learnability concerns learning the interface. D: **Incorrect:** Safety concerns avoiding harmful errors or outcomes.

**1. Identify the distinction:** Paper screens are manipulated manually to simulate interaction with users. This is paper prototyping. **Answer: B — Paper prototyping.** A: **Incorrect:** Storyboarding primarily depicts a narrative sequence. B: **Correct:** The paper screens simulate an interactive workflow manually. C: **Incorrect:** A digital mock-up is implemented with digital rather than physical screens. D: **Incorrect:** No running beta software has been coded.

**1. Identify the distinction:** The user can browse and check prices without being forced to authenticate. This supports freedom to explore before committing. **Answer: A — Freedom.** A: **Correct:** The action is available without an unnecessary prerequisite. B: **Incorrect:** Flexibility usually concerns multiple ways or shortcuts to perform a task. C: **Incorrect:** This does not primarily reduce the need to remember information. D: **Incorrect:** This does not describe consistency across interface conventions.

**1. Apply the effort adjustment:** \[E_{final}=E_{initial}\times EAF=20\times1.5=30\text{ PM}.\] **Answer: C — 30 person-months.** A: **Incorrect:** This omits the adjustment factor. B: **Incorrect:** EAF is multiplied, not treated as an arbitrary five-month increment. C: **Correct:** 20 multiplied by 1.5 is 30. D: **Incorrect:** The adjusted estimate is 30, not 35.

**1. Identify the distinction:** The Product Owner is accountable for maximizing product value and ordering the backlog according to business priorities. **Answer: B — Product Owner.** A: **Incorrect:** The Scrum Master supports Scrum effectiveness and removes process impediments. B: **Correct:** Value maximization and backlog ordering belong to the Product Owner. C: **Incorrect:** Project Manager is not a defined Scrum accountability. D: **Incorrect:** A technical lead does not by that role own business-value prioritization.

**1. Identify the distinction:** Velocity is the amount of estimated story work completed in a sprint, often expressed as story points per sprint. **Answer: C — Velocity.** A: **Incorrect:** Throughput generally counts completed work items per time period. B: **Incorrect:** Capacity describes available work resources, not completed story points. C: **Correct:** Completed story points per sprint are velocity. D: **Incorrect:** Burn rate concerns expenditure or resource consumption.

**1. Identify the distinction:** Cross-training spreads critical knowledge across the team, reducing dependence on specialists who may leave. **Answer: B — Cross-training team members.** A: **Incorrect:** Cutting scope may reduce load but does not preserve critical expertise. B: **Correct:** Cross-training directly reduces single-person knowledge dependencies. C: **Incorrect:** Third-party components do not necessarily replace the lost expertise. D: **Incorrect:** Automation does not by itself transfer understanding of the system.

**1. Identify the distinction:** The distinguishing property is that one operation’s output or result is required by the next. That is sequential cohesion. **Answer: B — Sequential cohesion.** A: **Incorrect:** Functional cohesion emphasizes one indivisible function rather than the stated chain of dependent stages. B: **Correct:** The operations are connected by a sequential producer-consumer relationship. C: **Incorrect:** Coincidental cohesion groups unrelated operations. D: **Incorrect:** Temporal cohesion groups operations because they occur at the same time.

**1. Identify the distinction:** Inheritance defines a specialization relationship: Book is a particular kind of Product. **Answer: C — Book is-a Product.** A: **Incorrect:** Has-a describes composition or aggregation. B: **Incorrect:** Uses describes a dependency. C: **Correct:** A subclass is a specialized instance of its superclass type. D: **Incorrect:** Being a part is not the meaning of inheritance.

**1. Identify the distinction:** A sequence diagram places objects on lifelines and shows messages in chronological order. **Answer: B — Sequence diagram.** A: **Incorrect:** A class diagram shows static classes and relationships. B: **Correct:** Lifelines and ordered messages model interactions over time. C: **Incorrect:** An activity diagram models workflow and control flow. D: **Incorrect:** A use-case diagram shows actors and high-level user goals.

**1. Identify the distinction:** Private state is accessed through controlled public methods such as getPrice() and setPrice(). This groups state with behaviour and hides the representation: encapsulation. **Answer: B — Encapsulation.** A: **Incorrect:** Inheritance specializes an existing class. B: **Correct:** The object controls access to its internal data. C: **Incorrect:** Association relates objects rather than hiding their internal state. D: **Incorrect:** Dependency describes reliance between elements.

**1. Identify the distinction:** Version history records commits, their authors and earlier snapshots. It supports identifying the faulty change and restoring or reverting to a known-good version. **Answer: B — Version history tracking.** A: **Incorrect:** Branching isolates work but does not alone identify historical changes. B: **Correct:** Recorded snapshots and authorship support investigation and rollback. C: **Incorrect:** The staging area collects the next commit’s changes. D: **Incorrect:** Distributed copies alone are not the history and attribution feature being asked about.

**1. Identify the distinction:** The incorrect line in the code is the program defect, or fault. The incorrect interest observed when it executes is the failure. **Answer: B — Fault.** A: **Incorrect:** Failure refers to the observed incorrect output. B: **Correct:** The erroneous source statement is a fault. C: **Incorrect:** Error refers to the developer’s mistaken action or reasoning. D: **Incorrect:** A test case specifies inputs and expected outputs.

**1. Identify the distinction:** Profiling attributes CPU time and memory usage to parts of the program, revealing runtime bottlenecks. **Answer: C — Profiling Tool.** A: **Incorrect:** Logging records events but does not systematically measure hotspots by itself. B: **Incorrect:** Dump-and-diff compares program states. C: **Correct:** A profiler directly measures CPU and memory hotspots. D: **Incorrect:** Backward debugging traces causes of behaviour rather than primarily measuring performance.

**1. Identify the distinction:** Each image-processing stage transforms its input and feeds the next stage. These independent transformations connected in a pipeline are pipe-and-filter. **Answer: B — Pipe-and-filter.** A: **Incorrect:** Client-server organizes requests to services. B: **Correct:** Pipes carry data between successive transformation filters. C: **Incorrect:** Peer-to-peer connects equivalent distributed participants. D: **Incorrect:** MVC divides model, presentation and input handling.

**1. Identify the distinction:** OrderService offers one operation that coordinates Order, Seller, Packaging and Delivery. It hides a complex subsystem workflow behind a simple facade. **Answer: B — Facade.** A: **Incorrect:** Adapter translates an incompatible interface. B: **Correct:** Facade provides a simplified unified entry point. C: **Incorrect:** Builder primarily constructs a complex object step by step. D: **Incorrect:** Factory primarily centralizes object creation.

**1. Identify the distinction:** E-books must implement physical packing and shipping operations that they do not use. Splitting the interface by relevant responsibilities would avoid this dependency. **Answer: B — Interface Segregation Principle.** A: **Incorrect:** Open-Closed concerns extension without editing existing code. B: **Correct:** Interface Segregation prohibits forcing clients to depend on irrelevant methods. C: **Incorrect:** Liskov Substitution concerns preserving behavioural contracts under substitution. D: **Incorrect:** Dependency Inversion concerns abstract versus concrete dependencies.

**1. Separate capability from quality:** A five-second display limit constrains performance; consistency over time concerns reliability; recovery from bad input concerns robustness. Updating prices is a functional capability. **Answer: A, B, D — Performance, reliability and robustness.** A: **Correct:** The five-second limit is a performance quality requirement. B: **Correct:** Consistent operation over time is a reliability property. C: **Incorrect:** Updating a price specifies a function the seller can perform. D: **Correct:** Recovery describes robustness against invalid input.

**1. Recognize model-based estimation:** These techniques use mathematical relationships, often fitted to historical data, to map project size and other drivers to effort. COCOMO is an example. **Answer: A, B, D — Mathematical models, size–effort relations and COCOMO.** A: **Correct:** The effort relationship is represented mathematically. B: **Correct:** Size is a major predictor in models such as COCOMO. C: **Incorrect:** A quantitative model is not solely expert intuition. D: **Correct:** COCOMO is a parametric effort model.