Teaching with Elly Thorsen: Odd One Out: A Strategy to Get Students Thinking Critically in Any Subject

Example Odd One Out Problem

Have you ever played the game Two Truths and a Lie? It is generally used as a simple and fun icebreaker activity where each person gives three statements about him or herself and others guess which one of the three is a lie. “Odd One Out” is a lot like that except it can be used as a way for students to think critically about a topic. I first learned about this strategy at a science team meeting several years ago. I am not sure of its official name, but Odd One Out seems appropriate. Odd One Out problems consist of a circle divided into four equal parts. Each quarter lists a word or phrase from a related topic. One quarter’s topic does not quite fit with the others though.

How to Make and Solve an Odd One Out Problem

To make an Odd One Out problem, choose four words or ideas from a related topic and arrange them in the four quarters of a circle. One of those parts should be just a little different than the others. Take the topic of colors, as seen in the example above. All four parts contain a color, but one doesn’t quite fit. Know which one?

Once you identify the odd one out, circle or shade that quarter. Then explain your answer. An explanation might sound like this, “Red, yellow, and blue are primary colors. Orange is the odd one out because it is a secondary color, meaning it is the result of two primary colors mixing.”

When I assign Odd One Out problems to students, I require them to write a sentence explaining why their chosen quarter does not fit. Their explanation is the most important part of the problem because it shows whether or not they truly understand the topic. Also, in some cases, an Odd One Out problem can have more than one correct answer causing the explanation to become even more valuable. This can promote student discussion and build even stronger critical thinking skills.

Odd One Out Problems with Multiple Correct Answers

Consider this example with actors. What answer would you choose?

Who is the odd one out? Is there more than one correct answer?

You probably picked Jennifer Lawrence because she is the only female listed. But can there be another correct answer? If you know a little more about these actors, you might realize all but one of them are American. Therefore, the Australian Chris Hemsworth could also be a correct answer. In fact, there are a number of correct answers to this problem. Knowing more about a topic can lead to a greater variety and depth of answers.

Answers that Are Not Really Answers

Sometimes, you might have students whose explanations cannot be considered correct. For example, in the above problem about actors, you might have a student with an answer like this, “Clint Eastwood is the odd one out because he’s the only one whose name begins with a vowel.” Yes, technically this is correct. However, it has nothing to do with the topic of these actors. To avoid getting answers like this, remind students that their answers have to do with the topic at hand.

Use Odd One Out Problems in All Subject Areas

One of the awesome things about Odd One Out problems is how versatile they are. They can be relatively easy to solve or provide quite a challenge. Students can use their understanding of a topic to make their own problems to test their classmates. They can be used for a ton of different ages, ability levels, and subject areas. Look at the examples below from each of the core subjects for ideas to start using Odd One Out problems in your classroom.

Example of a Completed Odd One Out Problem Set

The Elements, Compounds, and Mixtures worksheet below is available in my Teachers Pay Teachers store along with a number of other science related Odd One Out worksheets. You'll even find a blank, fully editable Odd One Out Worksheet that you can use to make your own creations.