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

# Terminology

> Key terms and concepts used in Dema's incrementality testing documentation.

<Info>
  This guide explains the key terminology used throughout Dema's incrementality
  testing documentation to help ensure clarity and consistency.
</Info>

## Test Structure Terms

### Treatment and Control Groups

**Treatment Group**
Regions where marketing spend is modified for the experiment. There are three types of treatment:

* **Holdout treatment**: Regions where ads are paused or reduced
* **New channel treatment**: Regions where new channel ads are added
* **Scaling treatment**: Regions where marketing spend is increased or decreased

**Control Group**
Regions where marketing spend continues as usual (business as usual). Used as the baseline for comparing treatment effects.

### Geographic Terms

**Commute Zones**
Clusters of zip codes that represent real-world consumer movement patterns, accounting for how people shop across city boundaries.

**Regions**
Geographic areas (typically groups of zip codes) used to segment test and control groups.

## Statistical Terms

### Confidence and Precision

**Confidence Interval**
The range of values within which the true incremental impact is likely to fall, indicating the precision of results.

**MDE (Minimum Detectable Effect)**
The smallest change in performance that can be reliably detected by the test given its design.

### Experiment Metrics

**Treatment Group Proportion**
The percentage of regions assigned to the treatment group (e.g., 13%). A lower proportion means fewer regions are affected by the test intervention.

**Estimated Lift**
The predicted percentage change in performance (e.g., -9.96% indicates an expected decrease in performance when ads are paused in a lift test).

**Minimum Detectable Effect (MDE)**
The smallest percentage change the test can reliably detect (e.g., -9.96% means the test can identify true effects of this size or larger).

**Treatment Group Correlation**
How well the treatment and control groups match historically (e.g., 94.61%). Higher correlation (>90%) indicates well-matched groups for reliable comparison.

### Analysis Methods

**Synthetic Control**
A weighted blend of control regions created to best match the treatment region's historical performance patterns.

**Incremental Factor**
The ratio of incremental value to spend, representing either incremental ROAS or epROAS depending on the target variable.

## Test Types

### Platform-Specific Terms

**User-level Treatment**
Used in platform studies (like Meta's Conversion Lift), where individual users are randomly selected to not see ads.

**Regional Treatment**
Used in Dema's geo-testing, where entire geographic regions have their marketing spend modified.

### Time Periods

**Pre-treatment Period**
The baseline period before the test begins, used to verify group matching.

**Post-treatment Window**
The observation period after the test ends to capture delayed effects of marketing.

<Note>
  For any terms not covered here or for more detailed explanations, please reach
  out to your Dema specialist.
</Note>