Data Preparation for AI: Why Cleaning Data Takes Up 80 Percent of the Work

In AI projects, the spotlight often shines on complex models and advanced algorithms, but the real foundation is well-prepared data. Around 80 percent of AI work is actually spent on cleaning and preparing data before it can be used. This article breaks down the essential steps of data preparation, showing how good data transforms AI results and business outcomes.

What Is Data Preparation?

Data preparation means transforming raw, messy data into a form suitable for AI models. Raw data can come from many sources, like spreadsheets, sensors, or customer information. It often has missing values, errors, inconsistencies, or irrelevant information that need to be fixed.

This process includes three main tasks:

  • Cleaning: Fixing errors, filling in missing parts, and removing duplicates.
  • Preprocessing: Adjusting data formats, scaling numbers, and encoding categories.
  • Feature Engineering: Creating new variables that better represent the problem.

The Importance of Data Cleaning

Cleaning data is the first and often the most time-consuming step. Missing data, errors, duplicates, and inconsistent formats cause problems if left unaddressed. For example, missing values can be imputed using the average or median of available data to avoid losing important information.

Duplicates can distort results, especially in sensitive fields like healthcare where patient records might come from multiple clinics. Cleaning often requires a mix of automated tools and expert review to ensure accuracy.

Preprocessing: Preparing Data for AI Models

After cleaning, data needs to be shaped into a format that AI models can use. Numerical data is often scaled or normalized so that features with large numeric ranges do not overpower others. For example, income measured in thousands of dollars must be balanced with age measured in years.

Preprocessing also includes encoding categorical variables like colors or locations into numbers, using techniques such as one-hot encoding or ordinal encoding. For text data, removing punctuation and simplifying words helps natural language models understand content better.

Feature Engineering: Adding New Insights

Feature engineering means creatively combining or transforming data to make AI models more effective. For example, combining heart rate and activity level into a single feature called cardio stress can improve health risk predictions.

In business, features can include holiday effects in sales data or averages over time in GPS tracking. These new features help models learn faster and make better predictions.

Why Data Preparation Matters for AI Success

Clean and well-prepared data makes all the difference in AI projects. It reduces errors, improves model accuracy, and builds trust in AI results. While it may feel like a lot of effort, investing time in data cleaning, preprocessing, and feature engineering is critical to turning data into valuable insights.

Data preparation is not a one-time task but an ongoing process tailored to the problem, data sources, and models used. When done right, it becomes the cornerstone for better decisions and competitive advantage.

Ready to learn more? Listen to the full episode of 100 Days of Data titled "Data Preparation for AI" to hear Jonas and Amy share practical stories and deeper insights from real-world AI projects.

Episode video