Software Engineering and Web Technologies
What this domain tests
This section combines process models, requirement and design quality, testing levels and metrics, plus the fundamentals of HTML, CSS, JavaScript and HTTP-based web communication.
Process models
Waterfall is sequential with frozen requirements; prototyping clarifies unclear requirements; the spiral model is risk-driven and iterative; incremental delivery ships in slices; agile uses short sprints, a product backlog and daily stand-ups. Choose spiral when risk is high and requirements may change.
Design quality and testing
Good design has high cohesion inside a module and low coupling between modules. Verification asks whether we are building the product right; validation asks whether we are building the right product. Testing levels run unit, integration, system and acceptance. Black-box techniques include equivalence partitioning and boundary value analysis; white-box techniques include statement, branch and basis-path coverage.
Worked example
A control flow graph has 9 edges, 7 nodes and 1 connected component. Cyclomatic complexity M = E - N + 2P = 9 - 7 + 2 = 4, so at least four independent paths must be tested. The reasoning: each new independent path adds one decision, and M equals the number of decisions plus one.
Web basics
HTML gives structure, CSS presentation and JavaScript behaviour. GET is safe and idempotent and can be cached; POST submits data and is not idempotent. Key status codes: 200 OK, 301 permanent redirect, 400 bad request, 401 unauthenticated, 403 forbidden, 404 not found, 500 server error. REST services are stateless and address resources with uniform methods.
Traps that cost marks
- Swapping verification and validation.
- Reporting a defect as a failure, or an error as a defect.
- Confusing 401 with 403, or treating GET as safe for sending passwords.
- Reversing cohesion and coupling, and forgetting the +1 in complexity.