How to Run Ethical A/B Tests

Testing that respects users delivers better long-term results than manipulation A lot of A/B testing guidance ignores ethics entirely. Fake urgency timers might lift conversions, but they train users to distrust your brand. This is a cost that never shows up in your testing platform. There is a better way.

A/B Testing
User Experience

How to Run Ethical A/B Tests

Published on:
December 19, 2025
Author:
Jon Crowder
Jon Crowder

How to Run Ethical A/B Tests

A/B testing has become the default method for optimising websites, but somewhere along the way, the industry confused "what works" with "what's right." I've spent 15 years running experiments across e-commerce, lead generation, and service sites, and I've seen how easily testing can slide into manipulation at the exoense of chasing myopic targets .

This guide walks through a basic framework for running A/B tests that respects users whilst delivering business value. Not because it's morally superior (it is, and you should feel good when you do good), but because it's better CRO too.

A Lot of A/B Testing Guidance Misses the Point

There's a whole load of A/B testing advice that focuses on statistical significance, sample sizes, and winning variants. All important. But whilst pursuing the scientific method, they miss a key part of the scientific method in academia. Ethics. Contemporary science does not test life-saving drugs against placebo because that would be unethical. Contemporary CRO rarely asks whether the test itself is ethical, or whether short-term conversion gains come at the cost of long-term trust. If your CRO people are engaged with, and doing this, then hold onto them because that is rare.

Testing fake urgency timers or scarcity that isn't real might lift conversions by 8%. It also trains users to distrust your brand. That trade-off doesn't appear in your testing platform's reports, which is attributing in-session/short user behaviour only.

The Framework: Five Steps for Ethical Experimentation

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Step 1: Define the User Problem You're Solving

Before you test anything, identify the genuine user friction you're addressing.

Ask yourself: what problem does this user have right now, and how does my change help them solve it? If your answer involves phrases like "increase urgency" or "reduce hesitation," you're probably already on the wrong track.

Good user problems:

  • Users can't find product specifications they need to make decisions
  • The checkout process requires information we don't actually need
  • Mobile users struggle with navigation designed for desktop

Bad user problems:

  • Users aren't buying quickly enough
  • Too many people are reading our pricing page
  • Users are comparing us to competitors

The difference? One focuses on user goals. The other focuses on conversion goals that may conflict with what users actually want.

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Step 2: Develop Hypotheses That Respect User Autonomy

Your hypothesis should articulate how your change sincerely helps users to achieve their goals, which then improves business outcomes. This is a core of product development that I feel got lost when CRO moved away from being a product discipline, and towards being a marketing discipline.

Structure it like this: "By [making this change], we'll help users [achieve their goal] more easily, which should result in [business outcome]."

Examples of ethical hypotheses:

"By adding detailed size guides to product pages, we'll help users make more confident purchase decisions, which should reduce returns and increase satisfaction."

"By removing unnecessary form fields at checkout, we'll reduce friction for users who want to complete their purchase quickly, which should improve conversion rates."

Avoid hypotheses that treat users as obstacles to optimise around:

"By adding a countdown timer to product pages, we'll create urgency that pushes users to purchase before they leave the site."

"By hiding the full price until the final checkout step, we'll prevent users from abandoning during the journey."

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Step 3: Design Variants That Add Value

When creating your test variants, apply this simple test: would you want this experience if you were the user?

Not "would you tolerate it?" but genuinely prefer it?

Ethical variants typically:

  • Remove friction without removing information
  • Make processes clearer, not more opaque
  • Give users more control, not less
  • Lean into less favourable information in the interest of transparency
  • Provide value that users would miss if removed

Manipulative variants typically:

  • Create needless anxiety through artificial scarcity or urgency
  • Hide information or functionality that users need for important decisions
  • Move the goalposts on the user
  • Make unwanted actions easier than desired ones
  • Add pressure without adding value

Here is a practical example: testing product page layouts.

Ethical approach: Test whether showing reviews above or below product details helps users make more confident decisions. You're optimising for information hierarchy and positioning.

Manipulative approach: Test hiding negative reviews or only showing 5-star ratings first. You're optimising user perception, not user experience.

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Step 4: Choose Metrics That Measure User Success

Conversion rate is a business metric. It tells you whether users completed an action, not whether that action aligned with their goals or happened for the right reasons.

Track conversion rate, absolutely. But also track metrics that indicate whether users are genuinely served:

  • Time to complete desired actions (faster often means less friction)
  • Return rates or cancellation rates (indicating post-purchase satisfaction)
  • Support queries related to the tested area (indicating confusion or problems)
  • Repeat visitor behaviour (indicating whether trust increased or decreased)

If your variant improves conversion but increases returns, support tickets, or reduces repeat purchases, you've optimised the wrong thing.

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Step 5: Implement Winners That Maintain User Trust

Statistical significance tells you which variant performed better against your primary metric. It doesn't tell you whether you should implement it.

Before implementing a winning variant, ask:

  1. Did this win by helping users or by manipulating them?
  2. Would I be comfortable explaining this change to users directly?
  3. Does this change align with how we want users to perceive our brand?
  4. Are there any negative metrics that suggest problems?

If a test variant wins but feels uncomfortable to implement, trust that discomfort. The short-term conversion gain isn't worth the long-term trust cost.

Sometimes the ethical decision is not implementing a winning variant. Making that decision is prioritisation of sustainable growth over quick wins.

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Common Ethical Testing Questions

"If I'm not testing aggressive tactics, how do I compete with sites that do?"

You compete by building a relationship with users that your competitors can't replicate. Users increasingly recognise and resent manipulative practices. Sites that respect users create competitive advantage through trust and retention.

"Doesn't all persuasion involve some manipulation?"

There's a distinction between persuasion and manipulation. Persuasion presents information and lets users decide. Manipulation exploits cognitive biases to push users toward actions that may not serve them.

Highlighting genuine benefits of your product: persuasion. Creating fake urgency to prevent users from thinking clearly: manipulation.

"What if ethical variants lose tests?"

Then you've learned something valuable about user friction that the manipulative variant was masking. A deceptive variant that wins tells you users have a problem, but solves it through trickery rather than addressing the underlying issue.

Go back to step one and identify the real user problem.

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Testing in Practice: Two Examples

Example 1: Checkout Optimisation

Standard approach: Test adding "Only 2 left in stock!" messages during checkout to reduce abandonment.

Ethical approach: Test removing unnecessary form fields that slow users down. If stock is genuinely limited, show accurate stock levels on product pages where users make decisions, not during checkout where it creates pressure.

Result: The ethical approach reduced checkout abandonment by 12% by actually removing friction, rather than creating anxiety.

Example 2: Pricing Page Testing

Standard approach: Test hiding full pricing until users enter their email, then showing them a "special discount" to create reciprocity.

Ethical approach: Test clearer pricing presentation with transparent breakdowns of what's included at each tier. Help users understand value rather than obscuring it.

Result: The ethical approach increased trial signups by 8% and significantly improved trial-to-paid conversion because users understood what they were getting.

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The Long Game

Ethical A/B testing is not about being nice to users at the expense of business results. It's about recognising that trust is an asset that compounds over time, and that short-term conversion tactics and hacks often destroy long-term value.

After 15 years of running experiments, the pattern is clear: tests that genuinely help users consistently outperform tests that manipulate them once you account for retention, satisfaction, and lifetime value.

The web is full of sites that treat users as conversion targets to optimise. Another web is possible.

Ready to build an ethical experimentation framework? Get in touch to learn how ethical testing can drive sustainable growth while respecting users. Or discover our CRO agency services to see how we help businesses build ethical optimisation programmes.

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