Methodik und Arbeitsweise / Methodology and Working Approach
What the domain tests
Methodology questions examine how you plan, execute and verify work: test design, measurement strategy, sampling, analysis and quality assurance of your own results. The exam favours reproducible, planned approaches over improvised ones.
Concepts to master
Know the purpose of a test plan: objective, acceptance criteria, method, equipment, conditions and responsibilities, defined before measurement begins. Understand calibration and traceability, reference standards, repeat measurements and plausibility checks. Be able to distinguish verification (does it meet the specification?) from validation (is it fit for the intended use?). Understand sampling logic and the risk of generalising from a single observation. Know how to structure a comparison fairly by keeping conditions constant.
Typical traps
- Defining acceptance criteria after seeing the data, which biases the result.
- Using an uncalibrated or out-of-tolerance instrument and trusting the number anyway.
- Taking one measurement and treating it as representative of a population or a process.
- Changing test conditions between runs and then comparing results.
- Confusing verification with validation.
Worked example
You must confirm that a batch meets a 50 ± 2 unit specification. Write the plan first: sample size, measurement method, instrument and calibration status, ambient conditions, and the rule for pass or fail. Measure, record raw values, check plausibility against a known reference, then compare. Rule of thumb: if you cannot state in advance what result would make you reject the batch, the test is not yet designed.