The EDD Theorem for Education Design

Choosing the Right Trade-offs in Education Systems

Photo by Andrea Sonda on Unsplash

In the design of complex systems, trade-offs are unavoidable. You cannot have a bridge that is sturdy, beautiful, and cheap all at once. You can have one or two of those things, but not all three. Similarly, you cannot have software that is high-quality, low-cost, and quick-to-market. You have to choose. And yet, with education, many of us want the best of all worlds, no matter what our experience with other complex systems tells us is actually realistic. Perhaps we choose to believe that education can be everything to everyone because the stakes are so high — and yet, that very belief is what often leads to poor outcomes.

As an education engineer, I spend a lot of time thinking about the trade-offs inherent to the design of education systems. Of the many desirable qualities that one might like to see in education, three come to mind as particularly important: egalitarianism; depth; and, a fixed duration. In an ideal world, education systems would be able to prioritize all three of these qualities and thus maximize value for as many students as possible. However, as with building bridges or designing software, the real world demands trade-offs. An education system may only prioritize two of these three qualities simultaneously, and in doing so, necessarily precludes prioritization of the third. I call this the EDD Theorem for Education Design.

The real world demands trade-offs.

Different kinds of education systems make different tradeoffs within the EDD framework (again, the three qualities we’re evaluating are egalitarianism, depth, and duration). For example, community colleges trade away depth so that they can ensure egalitarianism and a fixed-duration (2–4 years). Highly-selective universities also prioritize a fixed-duration (typically four years), but unlike community colleges they favor depth rather than egalitarianism. The final combination, which prioritizes egalitarianism and depth over having a fixed-duration, is much rarer, but education systems that use this combination do exist, including those based on mastery-based learning (MBL).

All of these education systems require making a choice about what is most important. In the long-term, I believe that MBL ultimately leads to better outcomes for more people; however, it only works if you’re willing to trade away duration with the understanding that doing so will yield a better long-term return on investment. Recognizing and understanding these trade-offs is absolutely critical to anyone who is deciding on an educational path, and for that reason, I believe this is a topic well worth deeper exploration.


Trade-offs and Marketing

Trade-offs are ultimately about the allocation of limited resources (time, money, personnel, etc.) and how you apply them towards varied goals (speed, cost, quality, etc.). When you spend resources to achieve one goal, you necessarily reduce the pool of resources available to spend on others. In an ideal world, resources would be unlimited and this wouldn’t make much of a difference; however, in the real world, resources are virtually always limited. Furthermore, some goals are so contradictory that no amount of resources will allow all of them to be accomplished at once.

When you spend resources to achieve one goal, you necessarily reduce the pool of resources available to spend on others.

Take for example the design of distributed data stores. In computer science, this topic is described by a concept known as the CAP Theorem, which says that a distributed data store may only simultaneously guarantee two of the following three qualities: consistency; availability; and partition-tolerance. If the makers of distributed data stores were open about the fact that only two of these qualities may be prioritized at once, then consumers could make informed decisions based on their particular needs. However, the makers of these systems have an incentive to promote their product as though it made no trade-offs at all. This leads us to a serious challenge with trade-off principles like the CAP Theorem: they are only helpful if users have sufficient information to make good choices.

An example of marketing that ignores the inevitability of trade-offs.

Any product that is subject to trade-offs is likely to face a similar disconnect between marketing and reality. This is certainly true of software development but it’s also true of education — particularly coding education. It’s not hard to find coding bootcamps that promise high-quality outcomes in a fixed period of time and with no admission barriers whatsoever. This is why it’s vital to employ the EDD Theorem as a means of identifying and understanding the trade-offs that education systems are actually making.


Elements of the EDD Theorem

In order to understand the trade-offs inherent in any system, it’s first necessary to understand the individual qualities that are desirable in that system. Let’s take a moment to review the three elements of the EDD Theorem, which will in turn allow us to understand their interplay and why trade-offs between them are necessary.

  1. Egalitarianism: The prioritization of access to education for as many people as possible, regardless of background, prior educational achievement, financial resources, or credentials. A system that prioritizes egalitarianism aims to serve all of its students equally. Although everyone has the potential to achieve the same outcomes, personal dedication, commitment, and effort are still determining factors.
  2. Depth: The degree to which all facets of a given topic are explored in a given curriculum. High prioritization of depth leads to potentially better outcomes because fewer topics are left unexplored or unmastered.
  3. Duration: The establishment of a fixed time limit for the completion of a given curriculum. When duration is prioritized, it is fixed such that both students and instructors know exactly how long it will last and can plan accordingly.

EDD Tradeoffs

The EDD Theorem argues that an education system may prioritize only two of the three EDD elements simultaneously. If this is the case, then what do the necessary trade-offs mean for students?

  1. Egalitarianism + Duration: Education systems that prioritize egalitarianism and duration, such as community colleges, have very few admittance barriers. These systems are generally lower in cost than others because expense is a type of admittance barrier. The intent of these education systems is to provide a reasonably good education, in a fixed period of time, to anyone who is interested. The trade-off, however, is depth — a fixed-duration program that is open to everyone does not have any remaining resources (time, money, etc) to spend on ensuring that students master all elements of the curriculum.
  2. Depth + Duration: Education systems that choose the depth-duration combination, such as highly-selective universities, cover their curriculum in great depth while still keeping a fixed duration. This is only possible because such systems must necessarily sacrifice egalitarianism. In order to ensure that a sufficient portion of their students achieve the desired depth outcome, and do so in a fixed period of time, these systems have to raise significant admission barriers. Such barriers come in two primary forms: highly selective admissions processes, which only accept students with the right experience or credentials; and, high cost, which increases the amount that a school can spend on high-quality instructors and facilities.
  3. Egalitarianism + Depth: The final, and by far the rarest, combination is that of egalitarianism and depth. In these education systems, both very low admissions barriers and depth of instruction are simultaneously prioritized. MBL, which demands that students master concepts before they move on to the next concept, is one such system. However, MBL and similar systems are no panacea — they are still making a trade-off. In this combination, duration is not guaranteed and it ultimately varies for each individual student. Given that duration cannot be predicted, this type of system is best suited for those students who can afford to adopt a long-term mindset in expectation of a greater ultimate return on investment.

When you look at trade-offs through the lens of the EDD Theorem, it’s much easier to cut through the often misleading marketing copy used by many coding education programs.

EDD in Coding Education

As in traditional education, the coding education industry tends to greatly skew towards the egalitarianism-depth and depth-duration combinations. Most coding bootcamps and coding schools operate on one of two models: a highly selective admissions process that only admits students who are pre-positioned to achieve strong outcomes; or, no admissions process whatsoever but very limited depth of content. For its part, our program at Launch School is the only one that I am aware of that takes the MBL path by dropping admission barriers and still covering material to mastery, albeit at the expense of a fixed-duration. If you were to map out the EDD prioritization of different education system types, Launch School’s place in it might look like this:

When you look at trade-offs through the lens of the EDD Theorem, it’s much easier to cut through the often misleading marketing copy used by many coding education programs. Despite what a given program might tell you, it’s simply not possible to simultaneously be egalitarian, cover material to depth, and set a fixed duration. You have to choose between these attributes.


If trade-offs are a necessary part of designing any system, including education systems, then what does that mean for you, the prospective student? First off, it means that before making any decisions you should take the time to evaluate your options. It’s easy to fall victim to misleading marketing, which makes the process of making the right choice even more difficult. In the coding education industry this is especially pronounced because the promises that many programs make tend towards hyperbole. It’s therefore up to you to cut through the marketing and get to the core of the trade-offs that different programs are actually making. The EDD Theorem is one tool to help you do that.

Understanding the trade-offs inherent in different education systems is, however, only part of the equation. The other part is you. It’s important to remember that when your chosen educational program makes a trade-off, so do you. If egalitarianism is important to you, then a highly-selective or high-cost program isn’t the right choice. If depth is important to you, then a shallow program is not going to get you where you want to go. And if a fixed-duration is one of your priorities, then a self-paced program might not be right for you.

Trading away a fixed duration may feel less safe, but in fact it’s the safest choice if you’re aiming for a long career.

At Launch School, we recognize that every education system requires making trade-offs, including ours. As an MBL-based system, we prioritize egalitarianism and mastery at the expense of a fixed duration. We make this trade-off because we strongly believe that learners should trade off duration in favor of egalitarianism and depth because doing so is worth it in the long run. Anyone can learn to code and anyone can learn it to depth, but there’s no guarantee that it will fit neatly into a 3 or 6 or 10 or 24 month timeframe. MBL allows anyone to reach mastery and competency, but the trick is to understand the trade-off involved — there’s no timeframe for graduation. Trading away a fixed duration may feel less safe, but in fact it’s the safest choice if you’re aiming for a long career.

Mastery-based Learning in Action

Besides Launch School, the most common place where we see MBL in action is in martial arts. For example like many martial art disciplines, Taekwondo has a mastery-based progression designated by the color of the practitioner’s belt. A black belt signifies the highest level of mastery. A student of Taekwondo starts out as a white belt and it’s only through a demonstration of mastery that she is allowed to progress to the next level belt — yellow. After that, she must perform another, more rigorous demonstration, in order to progress to the next colored belt — orange. The process repeats for the green belt, then purple, blue, brown, etc. How long does it take to reach black belt mastery? No one can say for certain. Anyone can start at white belt and anyone can progress through the colored belts, but no one can know how long it will take to reach a certain color. This is trading away duration for egalitarianism and depth, and this is the path to mastery.


Chris Lee is an instructor at Launch School, an online school for software engineers. He has over 16 years of software engineering experience ranging from large enterprise to startups. He enjoys programming, teaching and talking about Mastery Based Learning.