ASO course · lesson 36 of 60

ASO creative testing: write an experiment brief

Write a complete hypothesis and production brief that can lead to an interpretable test.

By Gabriel Machuret · Editorial methodology

Before you start: Reviewed creative concepts, a metric dictionary and available store traffic context.

See the worked example ↓

Module 6: Creative strategy and production

Two creative variants stand beside separate test paths and a decision lever.
Gabriel Machuret wearing an ASO Guru T-shirt, holding two phone mockups labelled A and B.

Your instructorGabriel Machuret

About 19 minutes reading · 36 minutes practice

You will produce: Module project: a test-ready creative pack with an approved experiment brief.

State the causal idea

Write “Changing X for audience Y should affect metric Z because…” and make the reason specific. “New screenshots will perform better” is not enough. Explain the current misunderstanding and how the treatment addresses it. A concept may change several coordinated elements, but then the conclusion concerns the concept as a whole rather than an isolated color or headline.

Define the comparison before production

Describe the control, treatment, eligible population, primary metric and guardrails. State what stays fixed and list concurrent work that could interfere with interpretation. Confirm that the chosen platform supports the design. A targeted page with a different audience is not automatically a randomized creative test, and a before-and-after comparison carries different limitations.

Plan all possible outcomes

Write what you will do if the treatment looks better, worse or inconclusive. Include operational stop conditions for incorrect assets or product problems. Do not prescribe one universal duration or sample size without the design assumptions. The next module develops evaluation in detail; this lesson ensures the design team produces an answerable question rather than simply another asset set.

Quick check · pick a response

Make the call before you scroll.

A test changes headline, artwork and order. What can a positive result establish?
Go deeper: practical decisions and tradeoffs

Write a mechanism, not just a variant name

A useful hypothesis connects an observation, a proposed change and an expected behavior. “Version B will win” explains nothing. “Showing a completed journal first may reduce navigation confusion and improve acquisition among suitable visitors” identifies a mechanism. Specify the control and treatment exactly. If multiple assets change together, label the treatment as a package and limit the interpretation accordingly. Accuracy corrections should be completed and logged before testing uncertain persuasion choices.

Specify the audience and measurement boundaries

Name store, locale, eligible traffic, primary metric and its denominator. Include a downstream guardrail where measurement supports it. Record concurrent campaigns and app changes that could complicate interpretation. Verify the platform's experiment eligibility and current method rather than imposing a generic calculator on native results. Plan what the team will do for improvement, decline and inconclusive evidence. The brief should make those decisions possible before anyone sees a favorable-looking chart.

Prepare a reproducible production handoff

Give the publisher exact asset IDs, ordering, localizations and approval status. Keep the previous control and the proposed treatment side by side. Record launch verification, experiment configuration and the person responsible for reading results. A design folder alone is not an experiment brief. If a late revision changes the treatment after review, update the hypothesis and manifest before launch. Otherwise, the readout may describe an experiment that never actually ran.

Platform references for this work: Apple — Product page optimization overview · Google Play — Run store listing experiments

Your turn · two-minute exercise

Try the scenario. Make your case.

A designer changes the opening image, icon and all captions together. Rewrite the brief as a package test and explain which individual causal claims the eventual result will not support.

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Your step-by-step procedure

From observation to action
  1. Write the hypothesis with audience, change, metric and mechanism.

  2. Specify the control and treatment assets, including what remains unchanged.

  3. Verify platform support, traffic context and measurement definitions.

  4. Agree decision rules, operational checks and owners before production sign-off.

Completed example · use the reasoning

A creative experiment brief

Gabriel’s take: If you change everything, you test the bundle. Do not award the victory to the orange button.

Constructed teaching material, not a client result. Adapt the evidence and product facts before using it for your app.

Control

Existing scenery-led opening

Treatment

Completed-journal opening with a matching benefit caption

Hypothesis

More eligible visitors recognize the recording task

Primary outcome

Exact supported native acquisition metric, recorded before launch

Decision

Adopt only if the result and operational checks support it; otherwise retain or investigate.

Your turn · repair the decision

Make the call. Then compare.

Both artwork and caption change. What can a favourable experiment support?

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Explore the supporting case and interpretation

Trail Notes tests a journal-led opening sequence against its existing scenery-led sequence. The hypothesis is improved recognition among eligible new visitors, measured through the chosen native listing outcome with product-quality context where available. Text and artwork change together, so any result concerns the whole opening concept. The brief explicitly rejects the narrower claim that the background color caused the outcome.

Brief field: Observation

Teaching example: Navigation confusion in research

Reason: Defines the problem

Brief field: Treatment

Teaching example: Completed journal shown first

Reason: Targets the suspected mechanism

Brief field: Primary measure

Teaching example: Native acquisition measure, exactly defined

Reason: Prevents denominator ambiguity

Brief field: Decision branches

Teaching example: Adopt, reject or investigate

Reason: Prevents forced winner selection

The hypothesis is plausible, but the qualitative observation does not prove that the treatment will improve acquisition. The experiment is designed to learn about that specific audience and implementation. If the result is inconclusive, the brief should allow a useful next step, such as revising the concept or choosing another research method. Keeping an honest inconclusive branch protects the team from rolling out an unsupported winner.

Build a handover someone can use

Hypothesis

Connect observation, change and expected user behavior with explicit uncertainty.

Asset manifest

Provide exact control and treatment files, order, locale and approvals.

Measurement

Define primary outcome, denominator, guardrails and platform method.

Operating plan

Assign launch QA, monitoring and responsibility for concurrent-change records.

Decision rules

Write actions for improvement, decline and inconclusive evidence before launch.

Your ASO assignment

Use your own app and evidence, or work through the teaching case. Keep your observations separate from assumptions and explain the reasoning behind your decisions.

Build something · track your work

Your assignment checklist

Tick each item after you have produced the work. Reading it does not count. The strategy deck will survive.

0 of 3 tasks checked.

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Assess your work

  • The proposed conclusion matches what the design can identify.
  • Assets and eligible audience are specified before launch.
  • An inconclusive outcome has a useful next action.

Common mistakes to catch

  • Changing several elements and attributing the result to one of them.
  • Choosing the primary metric only after seeing which one improved.

Sources and further reading

Platform references reviewed 29 September 2026. These sources support platform capabilities and constraints; the teaching frameworks, assignments and illustrative cases are original course material.

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