> ## Documentation Index
> Fetch the complete documentation index at: https://runrehearsals.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Recruiting a Cohort 

> Pick your cohort size of digital twins based on the kind of research you want to conduct. 

Cohort size depends on what kind of research you're running. Rehearsals conducts individual in-depth-interviews (IDIs) to extract strong reasoning and inferences from each digital twin.

## Two main kinds of research

| If you're doing…                                                                           | You need                                                                                                     |
| :----------------------------------------------------------------------------------------- | :----------------------------------------------------------------------------------------------------------- |
| **A gen pop, mass-market research**  — one simple question, read across a whole population | A large, representative sample: hundreds into the thousands, sized to the market(s) you're claiming to cover |
| **Concept testing with specific, screened audiences**                                      | 30–60 twins per cohort                                                                                       |

## Why 50 is a cohort sweet spot

For in-depth interviews, the themes settle early:

* **30** is our floor. Below that, one unusual replica moves the whole picture.
* **50** is the sweet spot — the shape is clear and the minority views have surfaced.
* **60 and up**, you're hearing the same things back. The difference isn't meaningful.

That's the same range traditional focus-group and IDI research runs at. You can make real decisions off rich feedback from 50 people.

## Scale by adding cohorts, not by adding people

If you need broader coverage, add another cohort: a different audience or a different screener. A bigger cohort tells you the same thing again. A new cohort tells you something you didn't know.

In analysis, you can surface insights by slicing across cohorts, including any demographic bucket in the countries' census (i.e. gender, HHI, geo, etc).

## If you can't find enough digital twins

As a Rehearsal customer, you get access to complementary recruitment as well as a set number of enrichment credits per month. Since Rehearsals has our own first party panel, let our team know who you'd like in your cohorts and we'll go find those digital twins for you.

<Note>
  Can't find the twins you want? Email [support@runrehearsals.com](mailto:support@runrehearsals.com).
</Note>