---
title: Minimum Detectable Effect (MDE) - Definition | RGM® Glossary
url: https://realgrowthmatters.com/glossary/minimum-detectable-effect-mde/
updated: 2026-06-10
source_html: https://realgrowthmatters.com/glossary/minimum-detectable-effect-mde/
---

Growth Glossary — Definition

SHT MINIMUM-DETECT

# Minimum Detectable Effect (MDE)

Smallest effect a test can reliably detect. A working definition from the RGM marketing glossary.

Smallest effect a test can reliably detect.

Term
:   Minimum Detectable Effect (MDE)

Field
:   Statistics & Analytics

Category
:   Statistics & Analytics

## A working definition

Worth a slow read.Minimum Detectable Effect (MDE) is an analytical concept your team should define once. A loose definition misaligns budgets and reporting.

Smallest effect a test can reliably detect.

Minimum Detectable Effect (MDE) belongs to Statistics & Analytics and refers to an analytical concept. A shared definition keeps the team aligned.

## The mechanics

Keep this in mind.Minimum Detectable Effect (MDE) produces value through how it is applied. Change the inputs and the right use of it changes too.

Minimum Detectable Effect (MDE) behaves unlike a fixed rule. An early-stage brand and a mature one will apply Minimum Detectable Effect (MDE) on different terms. The mechanics follow the inputs around it. Treat Minimum Detectable Effect (MDE) as a buzzword and the reporting misleads; agree on it and the numbers hold.

Keep the order simple: define Minimum Detectable Effect (MDE) for your context, then decide how to act. Reverse it and the budget chases a number nobody agreed on. Here is the short version.

## When it matters

One idea, plainly put.Reach for Minimum Detectable Effect (MDE) when a real decision rides on it -- a budget, a metric, or a comparison. Otherwise it is reference.

Minimum Detectable Effect (MDE) matters at the point of a decision. In statistics & analytics, three moments come up again and again. Outside them, Minimum Detectable Effect (MDE) is reference material.

1. **Setting budget.** Minimum Detectable Effect (MDE) clarifies which budget line deserves more.
2. **Choosing a metric.** Minimum Detectable Effect (MDE) tells you if the read reflects real effect.
3. **Comparing options.** Minimum Detectable Effect (MDE) evens out a comparison that would otherwise mislead.

## Worked example

One idea, plainly put.The walk-through runs Minimum Detectable Effect (MDE) through work modeled on Duolingo, so the concept meets real constraints.

Take Duolingo. During a power-analysis discipline, the team made Minimum Detectable Effect (MDE) the deciding input, not an afterthought. They set a baseline first, agreed one definition of Minimum Detectable Effect (MDE), and only then read the result: fewer false wins shipped. The number matters less than the order.

The numbers behind Minimum Detectable Effect (MDE) -- illustrative only, RGM analysis

| Stage | Action | The reason |
| Baseline | Read the starting point before any change to Minimum Detectable Effect (MDE). | A fixed point of truth. |
| Define | Agreed a single definition of Minimum Detectable Effect (MDE). | No room for scope drift. |
| Act | A power-analysis discipline — one variable. | Cause and effect, isolated. |
| Result | Fewer false wins shipped | An outcome you can trust. |

These Minimum Detectable Effect (MDE) numbers are illustrative -- RGM analysis. The structure travels; the specific figures do not.

## Where teams go wrong

Pick one definition.Four failure modes recur with Minimum Detectable Effect (MDE). Name them and they are easy to design around.

- **One blanket rule.** Applying Minimum Detectable Effect (MDE) the same way everywhere. Split it by audience, channel, and business model.
- **No anchor.** Quoting Minimum Detectable Effect (MDE) without a starting point. Always pair it with a baseline.
- **Wrong target.** Treating Minimum Detectable Effect (MDE) as the goal. The goal is the outcome it predicts.
- **Apples to oranges.** Comparing Minimum Detectable Effect (MDE) across firms raw. Adjust for pricing and cycle before you read it.

## Quick answers

What is Minimum Detectable Effect (MDE)?

Smallest effect a test can reliably detect. Settle what Minimum Detectable Effect (MDE) covers first; the strategy follows from there.

Why does Minimum Detectable Effect (MDE) matter?

Minimum Detectable Effect (MDE) earns its place when it shapes a real decision. The leverage is in correct use, not in the word itself.

Where does Minimum Detectable Effect (MDE) get used?

Minimum Detectable Effect (MDE) supports a real choice: where money goes, what gets measured, which option wins. The Duolingo case traces it.

Where do teams slip up on Minimum Detectable Effect (MDE)?

Using Minimum Detectable Effect (MDE) flat across every segment and showing it without context. Both make a guess look exact.

Where can I learn more about Minimum Detectable Effect (MDE)?

Start with the related terms below, then read the guide on marketing attribution models, plus marketing mix modeling.

What is Minimum Detectable Effect (MDE)?
:   Smallest effect a test can reliably detect. Settle what Minimum Detectable Effect (MDE) covers first; the strategy follows from there.

Why does Minimum Detectable Effect (MDE) matter?
:   Minimum Detectable Effect (MDE) earns its place when it shapes a real decision. The leverage is in correct use, not in the word itself.

Where does Minimum Detectable Effect (MDE) get used?
:   Minimum Detectable Effect (MDE) supports a real choice: where money goes, what gets measured, which option wins. The Duolingo case traces it.

### Go deeper

### Related terms