This post is for my fellow Instructional Designers, we who make the assessments for the trainings. We do much more than just this, of course. But when it comes to making a quiz or knowledge check or exam or whatever, it’s not our first rodeo.
Okay, seriously now…why is simple math such a problem for us? Why is it that we can’t get the basics down and standardized for the benefit of our learners?
Let’s all agree that the following mistake should NEVER EVER BE MADE when all the questions have an equal value:
Pass/Fail threshold = 80%
Number of questions = 4
- The Learner either answers 3 out of 4 questions correctly, which is 75% (FAIL!!!)
- Or they answer 4 out of 4 questions correctly, which is 100% (PASS)
- There is a 0% chance of the Learner scoring anything in between a 75% and 100%.
Why would we make our Learners looks stupid and ourselves look stupider?
Please don’t ever.
Please don’t ever, ever do this!
…Or anything like this!
Listen. There are no surprises here, we humans have had the math we need to prevent such problems for a few millennia now.If you need a math tutor, just go get one. No shame in that! I needed one in high school because I’m not very good at math either. And we all make mistakes now and again, but seriously…this is embarrassing already. Here’s a cheat sheet for how the math works in our assessment situation:
- 1–3 questions = Why bother scoring at all? Don’t kid yourself, this isn’t a real assessment. Do it or don’t.
- 4 questions = 75% (Learner can miss 1), this is the bare minimum if you want to call yourself a professional
- 5 questions = 80% (Learner can miss 1)
- 6 questions = drop one question and call it good
- 7 questions = add one more question and you’re done
- 8 questions = 75% pass (Learner can miss 2)
- 9 questions = drop or add one question, you’re almost there
- 10 questions = 70% (Learner can miss 3) or 80% pass (Learner can miss 2) or 90% if you’re being mean (Learner can miss 1)
- 11 question = drop or add one question, probably drop
- 12 questions = 75% pass (Learner can miss 3)
- 13 questions = drop one question and be done with it
- 14 questions = add one more question and it’ll work
- 15 questions = 80% pass (Learner can miss 3)
- 16 questions = 75% pass (Learner can miss 4)
- 17 questions = drop one question, no one makes 17 of anything
- 18 questions = drop/add two questions, prettier to add two more
- 19 questions = add one more question, so close!
- 20 questions = either 70% (Learner can miss 6) or 75% (Learner can miss 5) or 80% (Learner can miss 4) or 85% (Learner can miss 3) or 90% (Leaner can miss 2) or, if you’re feeling mean 95% (Learner can miss 1)
It goes on like this as you’d expect, in predictable little mathematical multiples. The multiples of 4 or 5 tend to work out nicely. The other multiples don’t really, at least until you get up to 60 questions or so — which is generally overkill.
Avoid the urge to create the “83.33333% or better to pass” scenario and just keep it simple.
It’s not hard. So don’t make it hard.
This isn’t rocket science, it’s not even algebra. Getting this kind of thing right is basic, entry-level proficiency.
Getting this kind of thing wrong means you don’t care enough to even think about it. So why should your Learner care about the rest of what you made? Keep in mind that this really does matter to the person on the other end of your assessment. Be straight with them. Make your assessments clearly correct to their eyes.
If you care about your people, you owe it to them to get this right. Care enough to design your assessment well. And if you don’t care that much, just hand the task off to someone else who does.
If you think I missed something here, or have a different use case to share, please say so in the comments! Yes, nitpicking is welcome and even encouraged!