Big Data and AI

Lesson 2.5 – Basic Data Cleaning Clean data is essential for accurate calculations, sorting, filtering, and analysis. Even small issues—extra spaces, inconsistent capitalization, or unwanted characters— can cause formulas to fail or produce incorrect results. In this lesson, you will learn simple but powerful tools to clean data quickly using Excel functions. 1. Why Data Cleaning Matters Raw data often contains problems such as: Extra spaces before or after text Inconsistent capitalization Non-printable characters from imported files Mixed formats (text that looks like numbers) Cleaning data ensures consistency and prevents errors in formulas and analysis. 2. TRIM – Remove Extra Spaces TRIM(text) removes extra spaces from text, leaving only single spaces between words. Example: Original: “ Product A ” Formula: =TRIM(A1) Result: “Product A” TRIM is essential when working with imported or manually typed data. ...