Ever since the start of the recent boom in free online college classes several years back, I have almost constantly been enrolled in or following at least one course, and often two or three at once.

Free online college classes are exactly what they sound like. A college simply records the lectures of a particular class and puts most of the materials for the class online for anyone to use for free. The catch, of course, is that they don’t actually advance you toward a degree; instead, they’re typically used for personal enrichment. Many courses offer the ability to pay a small fee in order to earn a certificate demonstrating that you successfully completed the course, which is nice and perhaps useful for a resume in a specific area, but most courses are available completely for free without a certificate.

My reasons for digging into these were straightforward. Sometimes, I dug into a class because it enabled me to gain a broad overview of a subject that I didn’t understand well, such as music theory. At other times, I dug into a class because it enabled me to start digging deeper into a few specific areas of personal interest, such as machine learning.

Along the way, I took some very good courses with instructors who did a great job of explaining topics and an abundance of materials online to read and follow. I also took some really awful courses with poorly recorded meandering lectures and no materials to help.

What follows are my ten favorite free online courses I’ve taken over the years. If you’re interested in the specific topics, I highly encourage you to give these free online classes a chance.

Introduction to Computer Science

Harvard University

Many people assume that computer science means learning how to program, but that’s not actually what it is. Perhaps the best description of computer science is figuring out ways of processing information and how to make those ways scale up. In essence, that’s what a computer does – it processes information.

Thus, the actual study of computer science often catches people by surprise. Rather than learning how to write code, computer science treats code as a pretty secondary thing. Instead, it’s all about processes and how to do them as efficiently as possible. If you have 100 files to alphabetize, how do you alphabetize them the fastest? Solving that problem on its own is the backbone of computer science; translating it to code is something of a secondary step.

This course lays out the basics of computer science in a very approachable way. I took this myself as a “refresher” as I studied computer science in college twenty years ago and I found it to be clear and interesting and engaging, more than I did back in the day. Perhaps I grew up, or maybe this is just a good class; either way, I found it really worthwhile.

Introduction to Political Philosophy

Yale University

Political philosophy is essentially the study of how groups of people come to govern themselves, determine right from wrong within the group, and develop appropriate benefits and consequences. This course goes through the long history of the development of political philosophy, from early experiments in democracy in ancient Greece and Plato’s writing on the subject all the way up to the modern day.

What I enjoyed most about this course is that the instructor was pretty non-judgmental about the topics. He mostly wanted to lay out some of the major ideas in political philosophy and chose to do it in a chronological order so that the student can see how one idea led to another. I didn’t notice a strong bias in his teaching and there were definitely ideas that would support all kinds of modern political persuasions.

If you’re interested in the “why” of how governments work and how people cooperate in large groups, you’ll find this to be well worth your time. A point of advice: do the readings along with the lectures here. Most of the readings are in the public domain and can easily be found online, though.

The Science of Everyday Thinking

University of Queensland

This is a rather practical psychology class that delves into how we all think in terms of everyday activities and choices. Why do we react like we do? Why do we make the decisions that we do? What basis is there for the seemingly rational and seemingly irrational decisions that I make? And, to a small extent, how can I make better ones?

This class delves into a lot of those ordinary decisions in depth, discussing things like how we process information presented to us, how we decide what and who to trust, and how to transition to slower and more reasoned and logical thinking for decisions rather than fast, instinctive choices.

The class is very practical, arguably the most practical one on this list. Much of the class deals with psychological blind spots that many of us have, particularly in terms of what things we choose to trust and how we make bad decisions. Quite a lot of it overlaps with personal finance decision making. It’s presented in an easy to digest manner and will leave you thinking quite a lot about your own behaviors.

Modern and Contemporary American Poetry

University of Pennsylvania

This class is a survey of American poetry over the last hundred to 150 years. The class centers around reading quite a lot of poetry and then delving into it to find deeper meanings and themes.

I took this class on a whim, mostly because I have always really enjoyed reading the poetry of Walt Whitman. His poems seem to have always been able to scratch some sort of itch on my soul and I wanted to understand his poetry better, so this class was recommended by a friend.

What I gained was a much deeper appreciation of poetry, not only in terms of appreciating the poems that others have written, but also appreciating the craft that went into them. I discovered the poetry of several others that I quite enjoyed and dug much deeper into the poetry of many that I was already familiar with. I now adore Dorothy Parker’s poetry, mostly thanks to this class.

Learning How to Learn

University of California San Diego

This class focuses on methods for self-learning and independent learning outside of a classroom setting. How does a person figure out how to tackle a topic, find trusted sources of information, and then integrate that information into one’s own knowledge in a meaningful way? That’s the key question that this class tries to answer.

As a sometimes meandering lifelong learner, this class was extremely useful to me as it helped me to direct some of that passion for learning in a more sensible way. I moved beyond merely reading tons of Wikipedia articles and piles of books – although I still do that, I now use several methods to extract more from those books and articles and really integrate the ideas within into my thinking.

These practices are things that are incredibly useful for students, of course, but they’re very valuable for anyone who has to learn things in the course of their work. Being a lifelong learner is invaluable in almost every career path these days and this class is all about effective techniques for the lifelong learner. I’m incredibly glad I took it.

If there is a “most universally practical” class that I’ve chosen for this list, it would either be this one or The Power of Everyday Thinking, listed earlier.

Machine Learning

Stanford University

Machine learning is a field within computer science that is focused on how computers can learn without being explicitly programmed to do so. Generally, this is done with computer programs that can evaluate large sets of data and find interesting and potentially hidden patterns within those sets without human intervention.

This is a topic area I dabbled in during my professional career and have always had a personal interest in, and over the last few years I’ve had an intellectual desire to get back up to speed on the topic. This course, along with a few books, was incredibly valuable in that regard.

I found the course to be surprisingly approachable, although I wouldn’t make this a “first taste” of computer science. This is a great follow up to the Harvard computer science course mentioned earlier in this article if you’re interested in the idea of machine learning.

Programming for Everybody: Getting Started with Python

University of Michigan

Naturally, with this interest in computer science, I also wanted to get back up to speed on how to actually write computer programs, and I chose to do this by learning Python. Although I wrote a lot of code back in my college years and early professional days, I didn’t use Python as a programming language at all.

This class was a really good introduction to using Python as a language, both for someone like myself with some background in programming in other languages, but also for someone who is completely new to programming. I watched portions of this class with my preteen son and he was able to pick up on most of what was going on and experimented with Python on his own.

You don’t need any software to try out the things described in this course – all of it is freely available and you can likely set it up easily on whatever computer you have access to. This makes it nice and easy to try out things on your own, which is most of the fun!

How to Write an Essay

University of California Berkeley

I took this course as part of an continuing effort to improve my own writing ability, with the goal of improving my ability to lay out a clear set of ideas that are enjoyable to read. After all, that’s essentially what I do for The Simple Dollar almost every day! This type of course is practically “continuing education” for someone like me.

As with most of the other courses here, I found this one to be extremely approachable. I found that many of the ideas presented were things that I felt in an intuitive fashion due to my own independent efforts and practice. At the same time, though, the course offered quite a few ways to improve those intuitive practices I had built up.

If you find that you need to write at any significant length for your work, or even wish to do so for pleasure, this class will offer quite a bit of value to you. I found myself even drawing upon this class when reading essays later on, as I could see many of the tactics and principles from this class being put to work by other writers.

Music Theory 101

Juilliard

Before taking this class, I knew next to nothing about music aside from what I “liked” and what I “didn’t like.” As a curious person, I find such a lack of depth of knowledge about a subject to be frustrating and I wanted to correct it.

This class certainly solved that problem. Music theory is simply the study of how musicians and composers make music, and it breaks down into a rather large number of interrelated ideas, from music appreciation to understanding musical notation to understanding how music triggers emotions and ideas. All of that and much more is presented in this course.

While it is accessible, I found myself going very slowly through this course because the sheer number of topics that I was unfamiliar with led me to go down a lot of different rabbit holes on my own. The material is presented well, but there is just a lot of material on a lot of areas. Still, by the time I completed the class, I felt that, between the class and my many side journeys, I had a much deeper understanding and appreciation of music than I had before.

American Government

Harvard University

This final course is a great accompaniment to the course on political philosophy mentioned earlier in this article; in fact, I’d actually recommend going through the political philosophy class first, because a major portion of this course ties in very well with political philosophy and how American government is an expression of many aspects of it. In other words, taken in tandem, you get a very nicely integrated “how” and “why” for American government.

I felt that this class spelled out exactly how America’s system of government works in a pretty even-handed fashion, covering both how it functionally works today (and, to an extent, over its history) along with a lot of the major debates on how it should function. This is another class where the recommended readings are very, very useful in terms of understanding the lectures in depth.

If you have a deep interest in how American government works or, perhaps more accurately, why it works the way that it does, this one will deeply scratch that itch.

Good luck in your journey for a deeper understanding of the world!