The Control group (%) option lets you hold back a percentage of eligible subscribers from receiving an activity. This gives you a like-for-like comparison group so you can measure the true incremental impact of your campaign.

How control-group targeting works

1. Build your target expression as normal in Setup & Target.
2. Go to the activity editor and navigate to Features > Testing.
3. Set Control group (%) to the holdout percentage you want.
4. Save and run an activity check.

Taguchi then splits your eligible audience into:

• Treatment group — receives the message
• Control group — excluded from the send

Selection logic and exclusions

• The control-group percentage is applied to subscribers who match your targeting criteria for that activity.
• Subscribers in the control group are intentionally excluded from message delivery.
• The remaining eligible subscribers become the targeted/sent group.
• If you set 0%, no control holdout is applied.

Measuring treatment vs control

Use activity reporting to compare outcomes between:

• Subscribers who received the activity (treatment)
• Subscribers who were in the control group (holdout)

This helps you separate natural behaviour from campaign-driven behaviour.

Common comparisons include:

• Conversion rate
• Revenue per subscriber
• Open/click engagement rates (where relevant)

A simple lift view is:

Incremental lift = treatment result - control result

Exporting or targeting subscribers in control group

Export or retarget holdout subscribers by using the control-group event in a target expression (for example, control-group activity 10). See the Target Expression Reference for supported resources.

Need help?

If you need help setting up control-group targeting or interpreting treatment-vs-control results, contact our support team.

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