Build a foundation in R and learn how to wrangle, analyze, and visualize data. This course covers common programming commands, how to operate on vectors, and when to use advanced functions such as sorting.

About this course

The first in our Professional Certificate Program in Data Science, this course will introduce you to the basics in R programing. You can better retain R when you learn it to solve a specific problem, so you’ll use a real-world dataset about crime in the United States. You will learn the R skills needed to answer essential questions about differences in crime across the different states.

We’ll cover R's functions and data types, then tackle how to operate on vectors and when to use advanced functions like sorting. You’ll learn how to use general programming features like 'if-else,' and 'for loop' commands, and how to wrangle, analyze and visualize data.

Rather than covering every R skill you might need, you’ll build a strong foundation to prepare you for the more in-depth courses later in the series, where we cover concepts such as probability, inference, regression and machine learning. We help you develop a skill set that includes R programming, data wrangling with dplyr, data visualization with ggplot2, file organization with UNIX/Linux, version control with git and GitHub, and reproducible document preparation with RStudio.

The demand for skilled data science practitioners is rapidly growing, and this series prepares you to tackle real-world data analysis challenges.

HarvardX has partnered with DataCamp for all assignments. This allows students to program directly in a browser-based interface. You will not need to download any special software, but an up-to-date browser is recommended.

What you'll learn

• Introduction to basic R syntax
• Basic R programming concepts such as data types, vectors arithmetic, and indexing
• How to perform operations in R including sorting, creating or importing data frame creation, basic data wrangling using dplyr and making plots
• How to perform basic programming with R
  

Learn basic data visualization principles and how to apply them using ggplot2.

About this course

As part of our Professional Certificate Program in Data Science, this course covers the basics of data visualization and exploratory data analysis. We will use three motivating examples and ggplot2, a data visualization package for the statistical programming language R. We will start with simple datasets and then graduate to case studies about world health, economics, and infectious disease trends in the United States.

We’ll also be looking at how mistakes, biases, systematic errors, and other unexpected problems often lead to data that should be handled with care. The fact that it can be difficult or impossible to notice a mistake within a dataset makes data visualization particularly important.

The growing availability of informative datasets and software tools has led to increased reliance on data visualizations across many areas. Data visualization provides a powerful way to communicate data-driven findings, motivate analyses, and detect flaws. This course will give you the skills you need to leverage data to reveal valuable insights and advance your career.

HarvardX has partnered with DataCamp for all assignments. This allows students to program directly in a browser-based interface. You will not need to download any special software, but an up-to-date browser is recommended.

What you'll learn

• Data visualization principles
• How to communicate data-driven findings
• How to use ggplot2 to create custom plots
• The weaknesses of several widely-used plots and why you should avoid them
  

Gain important foundational knowledge in probability theory, essential for a data scientist, as you learn key concepts using a case study on the financial crisis of 2007–2008.

About this course

In this course, part of our Professional Certificate Program in Data Science, you will learn valuable concepts in probability theory. The motivation for this course is the circumstances surrounding the financial crisis of 2007–2008. Part of what caused this financial crisis was that the risk of some securities sold by financial institutions was underestimated. To begin to understand this very complicated event, we need to understand the basics of probability.

We will introduce important concepts such as random variables, independence, Monte Carlo simulations, expected values, standard errors, and the Central Limit Theorem. These statistical concepts are fundamental to conducting statistical tests on data and understanding whether the data you are analyzing is likely occurring due to an experimental method or to chance.

Probability theory is the mathematical foundation of statistical inference which is indispensable for analyzing data affected by chance, and thus essential for data scientists.

HarvardX has partnered with DataCamp for all assignments. This allows students to program directly in a browser-based interface. You will not need to download any special software, but an up-to-date browser is recommended.

What you'll learn

• Important concepts in probability theory including random variables and independence
• How to perform a Monte Carlo simulation
• The meaning of expected values and standard errors and how to compute them in R
• The importance of the Central Limit Theorem
  

Learn inference and modeling: two of the most widely used statistical tools in data analysis.

About this course

Statistical inference and modeling are indispensable for analyzing data affected by chance, and thus essential for data scientists. In this course, you will learn these key concepts through a motivating case study on election forecasting.

This course will show you how inference and modeling can be applied to develop the statistical approaches that make polls an effective tool and we'll show you how to do this using R. You will learn concepts necessary to define estimates and margins of errors and learn how you can use these to make predictions relatively well and also provide an estimate of the precision of your forecast.

Once you learn this you will be able to understand two concepts that are ubiquitous in data science: confidence intervals, and p-values.

Finally, to understand statements about the probability of a candidate winning, you will learn about Bayesian modeling. At the end of the course, we will put it all together to recreate a simplified version of an election forecast model and apply it to 2016 election.

HarvardX has partnered with DataCamp for all assignments. This allows students to program directly in a browser-based interface. You will not need to download any special software, but an up-to-date browser is recommended.

Note that this course builds upon probability, the previous course in this series.

What you'll learn

• The concepts necessary to define estimates and margins of errors of populations, parameters, estimates and standard errors in order to make predictions about data
  
• How to use models to aggregate data from different sources
  
• The very basics of Bayesian statistics and predictive modeling

Data science projects involve keeping track of many data files and analysis scripts. Learn GitHub, git, Unix/Linux and RStudio to keep your projects organized and produce reproducible reports.

About this course

A typical data analysis project may involve several parts, each including several data files and different scripts with code. Keeping all this organized can be challenging.

Part of our Professional Certificate Program in Data Science, this course explains how to use Unix/Linux as a tool for managing files and directories on your computer and how to keep the file system organized. You will be introduced to the version control systems git, a powerful tool for keeping track of changes in your scripts and reports. We also introduce you to GitHub and demonstrate how you can use this service to keep your work in a repository that facilitates collaborations.

Finally, you will learn to write reports in R markdown which permits you to incorporate text and code into a document. We'll put it all together using the powerful integrated desktop environment RStudio.

In this course, you will learn what to download and how. We recommend an up-to-date browser.

What you'll learn

• How to use Unix/Linux to manage your file system
  
• How to perform version control with git
  
• How to start a repository on GitHub
  
• How to leverage the many useful features provided by RStudio

Learn an indispensable part of data science known as data wrangling, a process that involves converting raw data to formats needed for further analysis.

About this course

In this course, part of our Professional Certificate Program in Data Science, we cover several standard steps of the data wrangling process like importing data into R, tidying data, string processing, HTML parsing, working with dates and times, and text mining. Rarely are all these wrangling steps necessary in a single analysis, but a data scientist will likely face them all at some point.

Very rarely is data easily accessible in a data science project. It's more likely for the data to be in a file, a database, or extracted from documents such as web pages, tweets, or PDFs. In these cases, the first step is to import the data into R and tidy the data, using the tidyverse package. The steps that convert data from its raw form to the tidy form is called data wrangling.

What you'll learn

• Importing data into R from different file formats
  
• Web scraping
  
• How to tidy data using the tidyverse to better facilitate analysis
  
• String processing with regular expressions (regex)
  
• Wrangling data using dplyr
  
• How to work with dates and times as file formats
  
• Text mining
  

Learn how to use R to implement linear regression, one of the most common statistical modeling approaches used in data science.

About this course

Linear regression is commonly used to quantify the relationship between two or more variables. It is also used to adjust for confounding. This course, part of our Professional Certificate Program in Data Science, covers how to implement linear regression and adjust for confounding in practice using R.

In data science applications, it is very common to be interested in the relationship between two or more variables. The motivating case study we examine in this course relates to the data-driven approach used to construct baseball teams described in the book (also a movie) Moneyball. We will try to determine which measured outcomes best predict baseball runs and to do this we'll use linear regression.

We will also examine confounding, where extraneous variables affect the relationship between two or more other variables, leading to spurious associations. Linear regression is a powerful technique for removing confounders, but it is not a magical process, and it is essential to understand when it is appropriate to use. You will learn when to use it in this course.

What you'll learn

• How linear regression was originally developed by Galton
  
• What is confounding and how to detect it
  
• How to examine the relationships between variables by implementing linear regression in R
  

Learn the basics of machine learning, the science behind the most popular and successful data science techniques, to build a movie recommendation system.

About this course

Perhaps the most popular data science methodologies come from machine learning. What distinguishes machine learning from other computer guided decision processes is that it builds prediction algorithms using data. Some of the most popular products that use machine learning include the handwriting readers implemented by the postal service, speech recognition, movie recommendation systems, and spam detectors.

In this course, part of our Professional Certificate Program in Data Science, you will learn popular machine learning algorithms, principal component analysis, and regularization by building a movie recommendation system.

You will learn about training data, a set of data used to discover potentially predictive relationships and how the data can come in the form of the outcome we want to predict and features that we will use to predict this outcome. As you build the movie recommendation system, you will learn how to train algorithms using training data so you can predict the outcome for future datasets. You will also learn about overtraining and techniques to avoid it such as cross-validation. All of these skills are fundamental to machine learning.

What you'll learn

• The basics of machine learning
  
• How to perform cross-validation to avoid overtraining
  
• Several popular machine learning algorithms
  
• How to build a recommendation system
  
• What is regularization and why it is useful?
  

In this capstone course, show what you’ve learned from the Professional Certificate Program in Data Science. You will have the opportunity to create a long project of your own and have it assessed.

About this course

To become an expert data scientist you need practice and experience. By completing this capstone project you will get an opportunity to apply the knowledge base and skills in R data analysis you have gained throughout the series, including data visualization, probability, inference and modeling, data wrangling, data organization, regression, and machine learning.

Unlike the rest of our Professional Certificate Program in Data Science, in this course you will receive much less guidance from the instructors. If you complete the project you will have a data product to show off to potential employers or educational programs.

What you'll learn

• How to apply the knowledge base and skills learned throughout the series to a real-world problem
• Independently work on a data analysis project