Designing and making principles 3.2.1 Design methods and processes - Iterative design process — AQA A-Level Design and Technology: Product Design
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Designing and making principles 3.2.1 Design methods and processes - Iterative design process explained
Investigations supply the evidence a designer feeds back into each loop of the iterative design process.
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Primary data is gathered first-hand for the current project: interviews with users, observation of a task, questionnaires, ergonomic measurement, or testing a prototype. Secondary data already exists: published market reports, standards, competitor teardowns, sales figures or academic studies. The designer judges each source for relevance, reliability, bias, sample size and currency, then decides which data to collect and how, so findings can be compared and used to refine the design. Choosing the method is itself a design decision: a quick questionnaire gives breadth, a small observational study gives depth.
Your focus
- Classify a given data source as primary or secondary and justify the classification.
- Explain how investigation findings feed back into an iteration of the design process.
- Evaluate a data source against reliability, bias, sample size and currency criteria.
Designing and making principles 3.2.1 Design methods and processes - Iterative design process exam tips
Marking Points
- Distinguishes primary data (collected first-hand for the project, e.g. user interviews, observation, prototype testing, ergonomic measurement) from secondary data (already published, e.g. market reports, standards, competitor analysis, sales data).
- Explains that investigation findings inform decisions at each iteration of the design process, prompting refinement of the brief, specification or prototype.
- Evaluates sources for reliability, bias, sample size, relevance and currency before acting on them.
- Selects an appropriate method for the question being asked, recognising trade-offs between breadth (large questionnaire) and depth (small observational study).
- Recognises that secondary data may be cheaper and faster but less specific to the target user than primary data.
Examiner Tips
- 💡Name the specific method and say why it suits the design question, rather than writing 'do research'.
- 💡State how the findings would change a design decision, linking data to iteration.
- 💡When comparing sources, use criteria such as reliability, bias, sample size and currency explicitly.
Common Mistakes
- Treating any internet search as primary data: correction — data collected first-hand by the designer for this project is primary; published material found online is secondary.
- Assuming secondary data is always more reliable because it is published: correction — published sources can be outdated, biased or aimed at a different market, so they must be evaluated.
- Collecting data without a clear purpose: correction — the investigation should be designed to answer a specific question that informs the next iteration.