The pre-modeling process is a crucial first step in building a successful
Marketing Mix Model (MMM). This stage involves gathering, cleaning, and
organizing your data to ensure it's ready for modeling. A thorough pre-modeling
phase helps to build a reliable model. This section provides a guide to the key
steps in the pre-modeling process.

| Page | Description |
|---|---|
| [Collect and organize your data](https://developers.google.com/meridian/docs/pre-modeling/collect-data) | Learn how to gather and arrange your data for Meridian. This guide covers the essential data you'll need, like **media spend** , **KPIs** , and **control variables** . It also discusses recommendations for how granular your data should be in terms of **geography** , **time** , and **media channels**. |
| [Amount of data needed](https://developers.google.com/meridian/docs/pre-modeling/amount-data-needed) | Find out how much data you need for your **Marketing Mix Model** . This page explains how the right amount of data can vary. It covers the different data requirements for **national** versus **geo-level models** and offers solutions for situations where you might not have enough data. |
| [Geo-level modeling](https://developers.google.com/meridian/docs/pre-modeling/geo-selection-national-data) | Discover the advantages of using data broken down by **geographic regions** instead of **national-level data** . Using **geo-level data** can lead to more accurate and reliable model results by improving **statistical power** and reducing **potential biases** . This guide also offers tips on choosing your geographic areas and incorporating national data into a geo-level model. |
| [Use MMM Data Platform](https://developers.google.com/meridian/docs/pre-modeling/using-mmm-data-platform) | This guide shows you how to use the **Google MMM Data Platform** to source important data for your model, such as **Google Search trends** and **YouTube metrics** . You'll learn how to manage access, set up data delivery, and make data requests. It also breaks down the structure of the data you'll receive from various Google advertising platforms. |
| [Perform an exploratory data analysis](https://developers.google.com/meridian/docs/pre-modeling/perform-eda) | Learn how to perform an **exploratory data analysis (EDA)** , a critical step before building your model. You can generate an **HTML report** to visualize and validate your modeling data with Meridian's EDA package. This process helps you identify and resolve issues like **missing or inaccurate data** , and find **strong correlations** that could affect model performance. You will also explore how to apply **custom configurations** to tailor the exploratory data analysis to your specific dataset. |