What Is an Operational Definition

What is “Clean”?

What does “clean” mean? The Oxford English Dictionary defines it as follows [1]:

Free from dirt or filth; unsoiled or unstained: the usual opposite of dirty or foul.

It seems apparent. Now let's move on to practice. You enter a place and look around. There is no dirt, trash, or stains, but there is stuffiness and an unpleasant smell. Do you consider this place clean?

Or another example that parents of children might encounter. The child has made a mess, you ask them to clean up so that it becomes clean. They either immediately say that it is already good or clean up only the largest elements or only those that are visible without additional searches. Even if everything you consider necessary to clean is cleaned, you may internally disagree that it has become clean. After all, the floor is dusty, it would be good to vacuum and wash the floors. But for your interaction with the child, it has already become “clean”.

How is it that the word “clean” is the same, but there is no agreement with it? The problem lies in its definition. The one given above is lexical. That is, the idea is described in such a way that it is approximately understandable. If two people, when talking about “clean”, do not think one about “funny” and the other about “salty”, but both about the absence of dirt, then the lexical definition has fulfilled its task. But it did not fulfill our task.

The Operational Definition Defined

When it comes to practice and interested parties appear, the lexical or conceptual definitions are no longer enough. There is a need to confirm something that even can be a result of the complex behaviors. E.g., a modern car that is just manufactured. This is where what is called an operational definition arises. Let’s see what it is by looking at a quote from William Deming’s book “Out of the Crisis” [2]:

What is an operational definition? An operational definition puts communicable meaning into a concept. Adjectives like good, reliable, uniform, round, tired, safe, unsafe, unemployed have no communicable meaning until they are expressed in operational terms of sampling, test, and criterion. The concept of a definition is ineffable: It cannot be communicated to someone else. An operational definition is one that reasonable men can agree on.

The interesting point here is that the concept of “operational definition” is defined operationally. The “puts communicable meaning into a concept” is an action, the operation that occurs for measurable description to happen, ensuring that it is clear when a specific behavior occurs. It seems like there should be more description to “communicable” for the description to be more operational so it is clear when the communicable behavior occurs, but let’s not dwell on it for long. It’s time to start looking at examples.

The Operational Definition Examples

Defining Behavior of the Paper Cleaning Child

Let’s go back to the child who made a mess and define behavior in terms of cleaning up paper scraps. Imagine they cut out a figure from paper and the paper scraps end up on the floor. What in this case is “to make it clean”? Perhaps it is as follows:

• Remove all paper scraps from the floor.

Unfortunately, children sometimes tend to find workarounds for useful recommendations, so all the scraps may end up under the rug. A more precise way to operationally define the cleanliness after paper cutting might be as follows:

• Remove all paper scraps from the floor into a trash bag;
• Lift the edge of the rug near the table and remove the scraps that got there into the trash bag.

There could be a couch instead of the rug. If it were a cabinet with a low gap between the bottom and the floor, it is not necessarily that there would be a requirement to remove the paper scraps from under it. This could be too labor-intensive operation, requiring the participation of physically strong adults. This difficult part would not become part of the definition of “to make it clean”.

Maybe this meticulous approach will help you next time when communicating with your family members.

Defining Criteria for Consistent Washroom Cleanness

Now, I suggest looking at an example that makes it clean for visitors of a washroom today:

How to define “to make it clean in the washroom” when you strive for high-quality service for visitors and a positive image in their eyes? The checklist implies that the definition includes the following crucial steps:

• Replenish toilet paper supplies;
• Replenish paper towel supplies;
• Replenish soap supplies;
• Replenish hand lotion supplies;
• Replenish feminine hygiene supplies;
• Refill air freshener;
• Wipe sinks and fittings;
• Wipe mirrors;
• Check and wipe toilets;
• Pick up litter;
• Empty bins;
• Clean floors;
• Sign off on the work done after each cleaning;
• The supervisor signs off every several hours.

Such an operational definition was hardly created once. It is likely refined in the course of use until “to make it clean” no longer raises questions among interested parties.

It means that there was the feedback and data collection. The feedback loops allowing to gather data come from the systems thinking. Did you expect that we can go so far when defining behaviors of a cleaner?

Classic Example

The last of the examples again from Deming’s book. What is a “blanket consisting of 50% wool”? It can be defined in terms of the manufacturer:

• Take a certain amount of wool;
• Take the same amount of cotton;
• Carry out operations to produce the blanket.

The example turned out a bit like the joke “How to draw an owl” [3], but we won’t dwell on it for long. Few of us produce blankets, but many use them. How can a consumer determine whether a blanket meets the stated characteristics? How to collect data required for it?

Probably the definition would be convenient for if the blanket looked something like this:

A very nice example made for the ease of measuring. But would you be satisfied with such a blanket as its user?

If you need a more familiar blanket, measuring for the declared 50% wool content would be more difficult. The way to collecting data allowing to define the blanket might look like this:

1. Cut 10 holes in the blanket with a diameter of 1 or 1.5 cm in random places.
2. Number the cut pieces from 1 to 10 and send them for examination.
3. Expect a chemist to perform an analysis according to established procedures.
4. Ask the chemist to record the values for the weight fraction of wool in each piece.
5. Calculate the average wool content based on the results of 10 measurements.
6. Calculate the maximum wool content among the measurements.
7. Calculate the minimum wool content among the measurements.
8. Expect the average value to be ≥ 50% and ≤ 55%.
9. Expect (maximum – minimum) ≤ 2%.

To ensure the accuracy of such definitions, it is often helpful to refer to relevant research articles that provide insights into established methodologies and data interpretation.

This is how you can identify a “blanket consisting of 50% wool” as its user. Is this a good definition? It looks quite scientific and supporting the accurate data collection: random sampling, range of average value, maximum and minimum. Let this thought warm someone who goes to sleep covered with a blanket with 10 randomly located holes. So to speak, a 50% wool blanket with reduced blanket content.

Despite the flaw in the previous definition, it can be used for real-life purposes. For example, the manufacturer can attract an independent service for random blanket checks to regularly publish the results of the checks. This kind of assessment can help demonstrating the manufacturing consistency.

It is quite possible that there is a less destructive analysis done on the different levels of the blanket structure. We can focus on the radio analysis or something related to checking static electricity. Maybe there are even other concepts to try. This is not so essential for illustrating the topic; the operational definition provided above is sufficient to do the necessary measurement.

Conclusion

Such is a remarkable list of tasks, a defining to-do list if we describe it in other words. It is a useful tool when the parties are interested in some matter and simple dictionary definitions are no longer sufficient. An operational definition is not born at once; it is refined in the process of new attempts to satisfy those who depend on it.

Do you want to see other specific examples of clear and measurable descriptions (some of them are crazily long)? Read this blog post.

❓ Have you ever encountered operational definitions?

List of Links

[1] “Clean” from the Oxford English Dictionary
[2] William Deming, “Out of the Crisis”, ISBN 0-911379-01-0
[3] “How to Draw an Owl” from Memedroid