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OCR H446 1.2.3 Agile methodologies, XP and RAD

Part 2 of 6 · H446 1.2.3 · Software development

Agile development, extreme programming and rapid application development all respond to change, and H446 1.2.3 credit comes from explaining how each one does it and what it demands of people, feedback and technical capacity. This worksheet keeps the boundaries between the three visible while students apply them to briefs whose requirements are still moving.

Students will:

  • place extreme programming and RAD correctly in relation to agile development
  • explain how named XP practices support a frequently changing codebase, with a limiting condition
  • distinguish an agile increment from a RAD prototype in the same context
  • judge suitability when users are unavailable or safety requirements are fixed
  • correct shorthand advice such as RAD meaning simply coding faster

Inside: 6 explanation cells, 1 multiple-choice question, 2 fill-in-the-blanks cells and 4 written answers. 34 marks, about 45 to 55 minutes.

Series: H446 1.2.3 · Software development, part 2 of 6.

Shared by Coding PathwayVerified teacher

  • 13 cells
  • About 45 minutes
  • CC BY-SA 4.0
  • Shared 31 Aug 2026
  • Updated 3 Sept 2026

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The whole resource, exactly as a class sees it. Answers and marking are held back.

Agile methodologies, XP and RAD

Agile, extreme programming and RAD can all respond to change. A useful answer must explain how each does so and what people, feedback or technical capacity that mechanism requires.

Keep the boundaries visible

Agile, extreme programming and RAD boundariesRelated ideas: different boundaries and emphasis AGILE: family of iterative approachesshort iterationdelivers a usable incrementreview + feedbackreprioritises later work EXTREME PROGRAMMING (XP)a named agile approach with engineering practicespair programmingrefactoringfrequent testingcollective ownershipsmall releases RADrapid successive prototypes1 build prototype2 user evaluates3 refine and repeatrequires regular user access All respond to change, but compare the mechanism, emphasisand conditions each approach requires.

Agile is a family of iterative approaches: teams deliver small increments, review working software, receive feedback and reprioritise later work. XP is the specifically named agile approach in OCR's clarification. Its engineering practices include pair programming, frequent testing, refactoring, collective ownership and small releases. RAD develops rapid successive prototypes with end users, refining the solution until it is accepted.

Iteration is shared. That does not make all three labels interchangeable.

Worked context: volunteer rota service

The coordinator can review a usable rota every fortnight, and event rules change during the season.

An agile route can deliver login and basic shifts first, then use review feedback to reprioritise swaps and reminders. This reduces the risk of building a full system around stale requirements. It depends on regular stakeholder decisions and a team able to collaborate.

If code changes are frequent and reliability matters, XP practices add a quality mechanism: frequent tests detect regression; refactoring improves structure without changing behaviour; pair review can expose misunderstandings. Pairing and continuous collaboration also consume staff time.

Multiple choice1 mark

Which statement is most accurate?

  • AAgile means one fixed methodology with one compulsory set of roles
  • BXP is a named agile approach whose practices support frequent, high-quality change
  • CRAD means skipping user feedback so coding is faster
  • DPair programming alone proves that every project uses XP
Fill in the blanks3 marks
Agile delivers small gap 1 and reprioritises from feedback. XP adds engineering gap 2 such as refactoring and pair programming. RAD rapidly refines successive gap 3 with users.
  • increments
  • practices
  • prototypes
  • waterfalls
Written answer7 marks

Explain how two XP practices could improve a frequently changing codebase. Include one cost or condition that limits the benefit.

For each practice use practice → mechanism → code consequence; then qualify it.

Students type their answer here.

RAD model: prototype for learning

A museum wants a touch-screen guide before a fixed exhibition date. Staff cannot describe the layout precisely, but they can review a prototype twice each week. A rapid screen prototype lets them try navigation, text size and media placement early. Each evaluation informs the next version.

This supports usability and unclear interface requirements. It may be a poor fit if specialist staff cannot attend, if the project cannot be divided into quick prototypes, or if rapid visible progress hides demanding performance, safety or integration work.

Written answer6 marks

For the museum guide, distinguish an agile increment from a RAD prototype and state one reason XP practices could still be used in either route.

Compare the purpose of the produced software, then connect one XP practice to code quality.

Students type their answer here.

Apply the model independently

The remaining tasks change the context or reduce the support. Complete them without copying the worked model, then check that each explanation connects a mechanism to its consequence.

Written answer8 marks

A distributed team has an unavailable client, fixed safety requirements and a processor-intensive control algorithm. Evaluate the suitability of agile/XP and RAD.

Do not choose from one word. Apply collaboration, feedback/prototyping availability, code quality/performance and fixed requirements.

Students type their answer here.

Written answer5 marks

Correct this advice: 'Use RAD whenever the deadline is short because RAD is just coding faster. XP is different from agile because it uses pair programming.'

Repair both definitions and add one suitability condition for each.

Students type their answer here.

Fill in the blanks4 marks
Agile is a checkpoint gap 1 of iterative approaches. XP is a named agile checkpoint gap 2 with engineering practices. RAD uses rapid successive checkpoint gap 3 and requires regular user checkpoint gap 4.

Review your understanding

Before submitting, check that you can explain the main distinction in your own words, apply it in an unfamiliar context and justify each consequence rather than only naming a feature.