Test Design Technique Picker

A «Quantity» field accepts integers 1 to 999. You want the fewest cases that catch typical range errors (< >, ≤ ≥) at the edges.

Shipping cost depends on the combination of three independent boolean conditions: member? package over 5 kg? express delivery? You want to systematically cover every business-rule combination, not just test each condition in isolation.

A document moves through the states Draft → In Review → Approved → Published; some events (e.g. «publish») are only valid in certain states. Besides the allowed transitions, you also want to test invalid transitions (publishing a document still in Draft).

A field accepts any string between 3 and 20 characters. You want to group inputs so each group behaves the same way against the system, and test only one representative per group.

You must achieve 100% branch coverage of a critical pricing function's control flow.

A veteran tester explores, without scripts or written cases, an area where similar past releases hid concurrency defects.

An insurance premium is calculated by combining rules on age bracket, claim history (yes/no), and region. Auditors demand that every rule combination be exercised.

An ATM card flow: Idle → Card inserted → PIN ok / PIN fail (on the third failed attempt, the card is swallowed). You want to verify both the allowed and the blocked event sequences.

A date-of-birth field is tested in two steps. First step: it's partitioned into valid dates, future dates, and malformed strings, and one representative from each group is tested. Second step: additionally, 29 February and month-end dates (28/30/31) are tested specifically. Which technique is added in that SECOND step, targeting those specific boundary dates?

A time-boxed testing session on a brand-new feature that has no written specification yet, guided by a charter rather than predefined test cases.