A/B Testing & Experimentation

A/B Testing and Experimentation

Plan and run experiments that compare two experiences, measure real behaviour and replace opinion with evidence. No rigged demos, no invented win rates, just a fair question and a readable answer.

Two frosted glass slabs side by side split by a thin seam of light, amber and indigo tones
Custom visual · A/B Testing & Experimentation

Interactive demo · Experiment Flight Deck

Watch an experiment earn its answer

Choose the question first. The traffic, counters and readout stay quiet until you press Play demo, exactly how a careful test should begin.

1 · Choose the experiment question

Hypothesis

If the main action is impossible to miss, more visitors will add the bottle to their bag.

Decision rule

Consider shipping only if the variant improves add-to-bag rate without hurting checkout starts.

Ready when you are. Press Play demo to send the first visitors through.

00:00
50 / 50 split
A · Control Current page
Field series Field Bottle 750 $24 · 4.6 rating · 128 reviews Delivery charges appear later, at checkout 4.6 rating sits far below the price The action sits quietly lower on the page.
Visitors 0
Conversions 0
Rate 0.00%
B · Variant Test page
Field series Field Bottle 750 $24 · 4.6 rating · 128 reviews Free delivery · arrives Thursday ★ 4.6 (128) · Free returns · $24 Price joins the action, so the next step is obvious.
Visitors 0
Conversions 0
Rate 0.00%
Sample progress 0%

Waiting to start.

Observed difference —

The gap appears only after visitors arrive.

Readout No decision yet

A result is read after the agreed sample and guardrails are checked.

Run log

  1. SetupBrief agreed, split set to 50 / 50, traffic still at zero.

Illustrative demo with fixed, made-up data. A real experiment is sized for your traffic, measured with validated events and read honestly, including when the variant does not win.

Why it matters

Most website arguments are untestable opinions

The redesign debate, the hero banner debate, the button colour debate. Experiments settle them with visitor behaviour instead of seniority.

Two experienced people can look at the same page and disagree completely about what visitors want. That disagreement is fine. Acting on it without evidence is the expensive part.

A/B testing turns the disagreement into a question with a defined metric: if we show half the visitors a different experience, does behaviour change enough to matter? The process forces clarity before launch, because you cannot interpret a result you did not plan for.

Honest caveat: not every question deserves a test. Low traffic, long buying cycles or tiny potential gains often make a structured before-and-after analysis the better tool. Part of the work is recommending the right method, including when it is not A/B testing.

And results are read carefully: a variant with a higher number in an underpowered test has not proven anything. Sample size, segmentation and novelty effects are discussed before conclusions are drawn.

What you get

What an experimentation engagement produces

Everything needed to run a defensible test: hypothesis, design, measurement and decision framework.

  • 01

    Test backlog

    Prioritised hypotheses drawn from audit findings, analytics and customer questions.

  • 02

    Experiment design

    Metric, hypothesis, variants, audience split and success criteria in one document.

  • 03

    Implementation QA

    Checks that the variant renders correctly, events fire once and splits are random.

  • 04

    Monitoring

    Guardrail metrics watched during the run so tests do not quietly break something else.

  • 05

    Read-out

    What was tested, what the data supports, what it does not and what to do next.

  • 06

    Rollout plan

    If a variant earns confidence: how to ship it, how to keep measuring afterwards.

Framework

Anatomy of a useful hypothesis

Three illustrative examples of the format. Real hypotheses are written against your own findings.

H1 · Hierarchy

Because visitors cannot find the primary action, promoting the main CTA above supporting content will increase checkout starts, measured as begin_checkout sessions per product view.

Primary metric: checkout start rate · Guardrail: bounce rate

H2 · Reassurance

Because delivery cost appears too late, showing delivery timing and returns policy before the add-to-cart action will reduce abandonment on product pages, measured as add-to-cart rate.

Primary metric: add-to-cart rate · Guardrail: revenue per visitor

H3 · Forms

Because the enquiry form asks for unnecessary detail, removing two optional fields will increase completed submissions, measured as form completions per form view.

Primary metric: form completion rate · Guardrail: qualified lead rate

Implementation approach

The experiment lifecycle

  1. STEP 01

    Question

    Agree what decision the experiment will inform. If there is no decision attached, there is no test to run.

  2. STEP 02

    Design

    Write the hypothesis, choose the primary metric, set guardrails and size the sample against your traffic.

  3. STEP 03

    Build and validate

    Implement variants, verify rendering, confirm events fire correctly and check the traffic split behaves.

  4. STEP 04

    Run

    Let the test reach its planned sample while watching guardrail metrics. No peeking-driven early stops.

  5. STEP 05

    Decide

    Read the result against the original decision: ship, iterate or discard. The read-out documents the reasoning either way.

Scope

What experimentation includes (and what it does not)

  • Includes test strategy, experiment design, measurement validation and read-outs.
  • Includes working inside your existing testing platform, or setting one up if required.
  • Design and development of variant pages are scoped separately unless agreed otherwise.
  • We do not publish guaranteed win rates: no honest provider can promise what your visitors will do.
  • Illustrative metrics on this website are demo data, never CROLANE experiment results.

Traffic too thin for a reliable split test? The scope will say so and recommend a different method instead of selling you a test that cannot answer the question.

FAQs

Questions about a/b testing & experimentation

Something not covered? Ask us directly.

How do you decide what to test first?

By how much the change could matter, how likely it is to change behaviour, and how cheap it is to ship. We write the hypothesis, the metric and the decision rule before anything is built.

How long does an experiment need to run?

It depends on traffic and on how big a difference you want to detect. Rather than a fixed number of days, we size the test for your traffic volume so the read out is not a coin flip. If traffic is too low for a clean A/B test, we will say so and suggest alternatives.

What if the variant loses?

A loss is still a result: it tells you what your visitors responded to and prevents a change that would have wasted engineering time. Read-outs report both outcomes honestly.

Do you handle the tool setup as well?

If testing is not yet in place, the experiment setup and event validation can be part of the scope. If you already have a platform, we work inside it and document the configuration.

Start with a/b testing & experimentation

Tell us where the journey loses people.

Send a short note about the business problem behind this service. We will reply with honest thoughts on fit, scope and what starting would involve.