Book Image

CompTIA Data+: DAO-001 Certification Guide

By : Cameron Dodd
Book Image

CompTIA Data+: DAO-001 Certification Guide

By: Cameron Dodd

Overview of this book

The CompTIA Data+ certification exam not only helps validate a skill set required to enter one of the fastest-growing fields in the world, but also is starting to standardize the language and concepts within the field. However, there’s a lot of conflicting information and a lack of existing resources about the topics covered in this exam, and even professionals working in data analytics may need a study guide to help them pass on their first attempt. The CompTIA Data + (DAO-001) Certification Guide will give you a solid understanding of how to prepare, analyze, and report data for better insights. You’ll get an introduction to Data+ certification exam format to begin with, and then quickly dive into preparing data. You'll learn about collecting, cleaning, and processing data along with data wrangling and manipulation. As you progress, you’ll cover data analysis topics such as types of analysis, common techniques, hypothesis techniques, and statistical analysis, before tackling data reporting, common visualizations, and data governance. All the knowledge you've gained throughout the book will be tested with the mock tests that appear in the final chapters. By the end of this book, you’ll be ready to pass the Data+ exam with confidence and take the next step in your career.
Table of Contents (24 chapters)
1
Part 1: Preparing Data
7
Part 2: Analyzing Data
13
Part 3: Reporting Data
19
Part 4: Mock Exams

Managing duplicate and redundant data

Often in statistics or data analytics, we are told that more data is better, but that isn’t always true. If the data is duplicated or redundant, it can cause issues with skew, bias, or completely invalidate your analysis. Here, we will discuss the different ways you can have too much data, how this will impact your results, and what you can do about it.

Duplicate data

Duplicate data is when a specific data point recurs multiple times within a dataset. If we are looking at a spreadsheet, it means there are multiple rows with completely identical values. In the following table, we see a simple example of duplicate data:

Employee ID

LastName

FirstName

Department

Years With Company

83784

Benhill

Floyd

...