Interface interference · Australia

Trick question

Trick question is a working label for this design mechanism: A question or control uses confusing, reversed or leading semantics so the user's likely interpretation may not match the resulting choice. This is editorial implementation guidance for Australian journeys, not a finding of unlawfulness. From 1 July 2027, a similar interface is relevant to ACL section 28B only if the complete consumer-connection, manipulation or unreasonable-distortion and actual-or-likely-detriment test is met. Current ACL rules require a separate assessment.

Editorial implementation guidance
Also known as
  • trick wording
  • double negative
  • reversed checkbox meaning
  • inconsistent yes/no semantics
  • leading question
Journey stages

Definition

What is this pattern?

A question or control uses confusing, reversed or leading semantics so the user's likely interpretation may not match the resulting choice. This is a design and research taxonomy for learning and evidence review, not a statutory offence label or an automatic finding that an interface is unlawful.

How it works

A question or control uses confusing, reversed or leading semantics so the user's likely interpretation may not match the resulting choice. Negation, reversal or answer-label ambiguity breaks the link between the user’s response and the state that response will create.

Warning signs

  • A response control has a predictable semantic interpretation.
  • Negation, label structure or inconsistent conventions make that interpretation materially ambiguous.
  • The ambiguity favours a business outcome or creates plausible detriment.

Potential harms

  • A user may subscribe to promotions while believing they refused them.
  • The subscriber may preserve the plan accidentally because neither answer has a predictable consequence.

Learn by comparison

What does this look like?

These fictional examples make the design mechanism easier to recognise. They do not depict a real company and do not establish that an individual interface is unlawful.

Illustrative example 1 · Double negative controls marketing

A fictional signup asks users to tick “Do not untick if you do not want to miss offers”, making the resulting marketing choice hard to predict.

Potential consumer harm: A user may subscribe to promotions while believing they refused them.

Illustrative example 2 · Reversed wording in cancellation survey

A fictional cancellation dialog asks “Are you sure you don’t want us not to keep your plan active?” before displaying yes and no buttons.

Potential consumer harm: The subscriber may preserve the plan accidentally because neither answer has a predictable consequence.

What is a fairer alternative?

Use explicit action labels that name the resulting state, remove double negatives and verify that each response produces the consequence a user can reasonably predict.

Context matters

Context and boundary cases

  • A response control has a predictable semantic interpretation.
  • Negation, label structure or inconsistent conventions make that interpretation materially ambiguous.
  • The ambiguity favours a business outcome or creates plausible detriment.
  • Boundary to test: Unavoidable technical distinction clearly explained
  • Boundary to test: minor stylistic awkwardness with unambiguous outcome

When a similar design can serve a legitimate purpose

  • Unavoidable technical distinction clearly explained
  • minor stylistic awkwardness with unambiguous outcome

Operational review

What teams should review

Teams
  • Product
  • Design
  • Engineering
  • Legal
  • Compliance
  1. Do “Do not untick to opt out” and “Send me optional email offers” receive comparable prominence and explain their consequences before activation?
  2. Which fields or permissions are required, what happens on refusal, and does the resulting state support this criterion: “A response control has a predictable semantic interpretation”?
  3. What neutral rendering or comprehension result would falsify the classification, particularly in light of “Unavoidable technical distinction clearly explained”?
  4. Do “Yes / No” and “End plan on 30 September” receive comparable prominence and explain their consequences before activation?
  5. Can the dialog be dismissed, what action does each control trigger, and what later state confirms or contradicts “Negation, label structure or inconsistent conventions make that interpretation materially ambiguous”?
  6. What neutral rendering or comprehension result would falsify the classification, particularly in light of “minor stylistic awkwardness with unambiguous outcome”?

Evidence to retain

  • Annotated signup and cancellation screenshots at each responsive breakpoint
  • The complete state sequence before, during and after the consumer decision
  • Design-system component, content, default and configuration records for the reviewed release
  • Operational records substantiating price, availability, timing and eligibility claims
  • Usability, accessibility, reversal, complaint and support evidence relevant to consumer impact
  • A dated product and legal review record identifying evidence, uncertainties and release decisions

Legal map and implementation tools

Evidence base

Sources

  1. Dark commercial patternsOrganisation for Economic Co-operation and Development · Secondary · checked 2026-09-14 · OECD Digital Economy Papers No. 336
  2. Competition and Consumer Amendment (Unfair Trading Practices) Act 2026Federal Register of Legislation · Primary · checked 2026-09-14 · C2026A00064
  3. Competition and Consumer Act 2010, including Schedule 2: Australian Consumer LawFederal Register of Legislation · Primary · checked 2026-09-14 · C2004A00109
  4. Unfair trading tricks and traps to be bannedTreasury Ministers · Primary · checked 2026-09-14
  5. Inquiry into the Competition and Consumer Amendment (Unfair Trading Practices) Bill 2026Senate Economics Legislation Committee · Primary · checked 2026-08-09