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Course: Content creation best practices > Unit 2
Lesson 3: What should good rationales do?General principles of rationales
Rationale Basics
- Rationales should explain why each distractor is wrong and why the key is correct.
- Do not include the correct answer or clearly point to the correct answer in a distractor rationale (if possible to avoid). Remember that we want students to make another attempt to answer the question.
- Do not explicitly state “correct” or “incorrect” at the beginning of each rationale (this is already indicated in the product). If there are multiple reasons why a distractor is wrong, explain them all (within reason).
- Rationales should be written for every option, including the key.
- Each rationale should stand alone, meaning it doesn’t rely on any of the other rationales to make sense.
Below is an example of a set of rationales from a biology question. The first sentence explains the general meaning of the term being assessed and then explains how it is or is not exemplified by the answer choice. Although the first sentence of the distractor rationales gives the definition of phenotypic plasticity, it doesn’t give away the correct answer because the question still requires application of that definition.
You can also see here that a hint could also have given the definition of phenotypic plasticity that is included in each distractor but the rationales are able to and allow the user to also see why the application to a specific example is or is not correct.
In the following question, the rationales for the distractors do a good job of explaining why the features named in them are sometimes but not always parts of simulations. However, the first sentence of the rationale for the last distractor mostly gives away the correct answer and so is probably better removed.
Key and Distractor Rationales
- In the key rationale, confirm the correct answer and provide an explanation for how to get there.
- When writing key rationales for multiple select options, you only need to address the key at hand in each key rationale. You do not need to reference the other correct option(s).
- In the distractor rationales, if the distractor contains an obvious error in thinking or is highly likely related to a particular error or misconception, try to directly identify that error in thinking.
- Consider using language like, “This answer could be the result of…” to account for the possibility that some students may have arrived at that answer through other means.
- When there are multiple ways to solve a question, the rationales should generally commit to one approach. However, consider using language like, “This is one possible approach...” or “One way to think about this type of problem is…” to account for other possibilities.
In this test prep example, we see an example where the rationales for the second and third distractors are the result of a particular error that is then explained in the rationale. In this case, there is really only one way to get the incorrect answer (other than guessing) to get to that response, so the error is stated definitively.
Parallel Structure
- If possible, rationales in the same item should be written using parallel structures.
- For example, if the same principle is applied to evaluate each option, walk through the principle the same way in each rationale: “A correct answer should mention A and do B. This option mentions A but doesn’t do B.”
Both of the examples above have fairly good parallelism. The parallelism in the question about simulations could be slightly improved. What might that look like?
Each option could follow the pattern “A simulation often x, but not always/ necessarily.” We could consider whether it is appropriate for them all to have an example like the second option (first distractor) does.
Referrals
- Rationales should link back to language used in the stim/stem/options, if possible.
- Rationales should not introduce new or complex concepts but can remind students of relevant facts.
- Do not bring in outside examples.
- Do not teach prerequisite knowledge from earlier lessons or units.
- Rationales should not introduce new vocabulary unless absolutely necessary.
Images
- Rationales can include images when they help explain, relate to images in the question, or reduce the amount of written language in the rationales.
- To create a better user experience, images in rationales should be as small as possible (while still being readable).
The stim in this math example is graphical. The rationales make use of this and show how each distractor would look graphically, in a way that relates to the stim and makes the difference between the distractor and the correct answer immediately visible. Also note that the image in the rationale is smaller than the image in the question.