Logical thinking for beginners - What is MECE?

Hello, I’m Hoteida from the MCO (Market Creation Office). I am mainly in charge of planning and writing articles for our external outlets. 

There is a common concern among those who join beBit as non-UX consultants, which is whether or not they will be able to keep up with the glamorous consultants and individuals who think about UX and its value day in and out.

While there should be no worries if you went through the hiring process, we at the MCO engage in a variety of activities to enable the sharing of knowledge. In addition to activities such as the “UX Picks” Slack channel that shares UX related knowledge, we also have a member who originally worked as a consultant voluntarily host study sessions for the members. This article will share the details from the “logical thinking” study session that was hosted. 

It should be rather easy and approachable, and a bit of an unorthodox explanation of logical thinking. Since it is aimed for beginners, I would recommend it for new graduates and mid-career hires who are not familiar with the topic. 

Let’s get started! (Please don’t mind the sudden change in tone!)

What does it mean to “break down a topic”(MECE)?

When first starting to learn about “logical thinking,” one of the most difficult parts is “receiving a sample question that you don’t know the answer to.” If it is the first time you are learning this methodology, I suspect that solving a problem that you don’t know the answer to will not be very satisfying. 

Of course, logical thinking is used to challenge real-world problems for which there is no correct answer by hypothesizing what seems plausible, but honestly, it’s difficult to learn when there is so much that is unknown. 

And yet, those who teach logical thinking give only complicated examples. Maybe it's because they already know what they’re doing, or maybe it's because they want to look smarter by breaking down topics quickly. 

So, I have come up with an example that is easy to understand while at the same time convincing enough to continue your studies. The theme of this installment is “MECE” (we’ll have to see if there will be any future issues).

MECE stands for Mutually Exclusive, Collectively Exhaustive, meaning “there should be no overlap, while all the pieces combined should form the original item without any gaps.” The point is to classify items so that you aren’t confused where something should go. 

For the sake of visualization, let’s call each classification “boxes.” We must put the objects into the box with the correct classification written on it. 

Now let’s consider a non-MECE “where does this go” pattern using 2 beBit members. The first pattern is when there is an overlap, or when there are two or more boxes that a person fits in. For example, if you divide people into the two categories of “40’s” and “born in the summer,” you would be at a loss as to which one our CEO, Endo-san (born in August) would fit into. If it’s necessary for you to separate people by age and by birth season, you would first have to separate individuals into boxes by age, then by season (vice versa).

The second “where does this go” pattern is when there is no applicable box. If you are separating people by where they are born and only prepare boxes for Tokyo and the 6 other Kanto prefectures, Endo-san, who was born in Tottori, would not have a box. If we prepared boxes for all 47 prefectures of Japan, where would our Senior Vice President Jason, who was born outside of Japan, fit? The easiest way to avoid objects being left out would be to create an “others” box, but if you put too much into the “others” box, there would be no point in utilizing MECE. You must establish the information you are looking for and decide what you want to cover in the “others” box. 

After reading this far, some of you may be thinking that this thought process sounds familiar. The fact is, when you create a survey or form, the responses must be MECE in order to avoid confusion from your respondents. 

beBit consultants create surveys over and over in order to gather subjects for user behavior surveys. One might say that they are practicing MECE in the process. 

Sample Problem: Fruits!

Now, let’s get some practice. The topic can be anything, so let’s try using “fruits.” How would you separate fruits into groups?

I’ll list a few classifications that are not MECE first, so try thinking about what the issue is. I’ll explain them right away, so scrolling slowly is recommended. 

Classification 1: “①Eaten as is” or “②Eaten after peeled by hand”

① would be fruits like strawberries and cherries. ② would be fruits like bananas and tangerines. Then, what about fruits like melons…? It looks like there are some fruits that are not considered (I believe that no one eats melons without peeling them first… right?).

The key to MECE is to separate them into “is 〇〇” and “is not 〇〇.” In the example above, you can separate them into “Eaten as is” and “Cannot be eaten as is = they must be peeled prior to being eaten.” After separating into these 2 classifications, you can separate them further if necessary (e.g. peeled by hand or by knife).

Classification 2: “①Tasty” and “②Not tasty”

From the advice stated earlier, this should work as it’s separated into “is 〇〇” and “is not 〇〇,” right? Sure - it is classified without duplication or omission, but, the criteria for separating is a bit vague and may depend on personal preferences…

One of the purposes of MECE is to organize your thoughts in a way that is easy for others to understand and accept. If the perspective is too subjective, the listener will not be convinced. Even if you know that tastes vary from person to person, or rather, because you know this, you would be bothered if your favorite fruit were to end up in the “not tasty” classification. The perspective of the analysis needs to be objective so that it will be the same for everyone. 

Classification 3: “Little Ally, a 1 and a half year old, has eaten it” and “Little Ally has not eaten it”

This, once again, has taken the prior advice into consideration. Whether or not little Ally has eaten the fruit is factual and does not differ from person to person. 

But, does this classification have any meaning to those that have no relation to little Ally…?

It may be good for chit-chat, but unless everyone is planning a birthday party for little Ally, this classification would be too personal and would not make sense for most people. 

On the other hand, if everyone was actually planning a birthday party, then the classifications would be very meaningful.

In other words, no matter how MECE it may be, it is meaningless if it does not serve the purpose of analyzing. On the other hand, even if it seems extremely personal, if the analysis is in line with the purpose, there is great value. 

“Starting with the purpose” is always the basic premise of logical thinking. The question “how would you classify fruits?” is actually nonsense. To be precise, I would have had to ask “how would you classify fruits, and based on what purpose?” MECE is a means to an end; the purpose will always come first. If you are just starting to learn, it may be good for you to “do many MECE analyses in order to learn MECE.”

Why this example question was “easy”

Let’s think about why this “fruits” problem was an easy example. There are a few reasons, but the fact that you can imagine the objects is a big factor. 

There are 2 ways to do a MECE analysis - 1 is top-down and the other is bottom-up. The top-down method is done by placing labels on boxes like we did earlier. If you excel at abstract thinking, this is the method I would recommend. 

But, it’s difficult to think from the top-down, so until you get used to it, I would recommend thinking from the bottom-up. Start by listing the things that should be placed into boxes, and once you have a certain number of items, you can come up with the classifications. Once you come up with some classifications, you can choose which items go in which box. 
 
For our example, the subject was “fruits,” so it should have been relatively easy to imagine the items we needed to place in boxes. If that is the case, you can skip the first step of coming up with items to place into the boxes. Because the objects that came to mind were familiar, their properties were easily established and candidates for classifications should have quickly come to mind. 

When dealing with real world issues, the objects will be indefinite. What you think represents one thing may actually be a mixture of 2 things, and could also be the same as another. In the end, it becomes a matter of creating a habit, training, or in short, learning by doing. “Brainstorming” is a useful tool, but for this installment, I’ll stop my explanation there. 

This wraps up this installment. If this article is popular, there just might be another one! I can’t make any guarantees, but if you have any topics you’d like us to cover, please feel free to reach out to the MCO!