The Muddiest Point

Shared by Jonathan White

In September 2017, Alison Clark shared with us some information about a classroom assessment technique called "The Muddiest Point." As part of my participation in the Teaching for Learning TLC, I wanted to look into this a bit further, and make some "canned" quizzes that colleagues could use to try it out in their own lessons.

In Research

In the late 1980's, Derek Bok, then president of Harvard University, established monthly seminars for professors from around the university to examine and improve teaching and learning. As part of this, Prof Frederick Mosteller was inspired by a report on "Minute Paper" assessments (more on these soon!) to trial a series of three short questions asked to his students at the close of a lecture. These were asked several times over the course of the term, but not every lesson. The three questions were:

  • What was the most important point in the lecture?
  • What was the muddiest [most unclear or confusing] point?
  • What would you like to hear more about?

He collected and collated responses and shared them with students, and then later on gathered their feedback on the process.

Among the feedback he received, was a comment from one student who noted, "You give us the key points [Mosteller was in the habit of writing the principal points of a lecture on a side blackboard at the start and leaving them there throughout], and the ones we give you are much the same; and so you don't learn much about what we need, and our answers to what we want more of are too vague and general." This focused Mosteller on the value of the muddiest point question. Mosteller goes on to note in his conclusions that while he didn't find the "What was the most important point?" question valuable and wouldn't use it again, he could imagine teachers in other subjects might still find it useful if key points were less clear-cut. In regards to the third question, he found that it prompted him to create some handouts to further explore certain points that he might not otherwise have done, but in many cases what was requested by students overlapped with the answer to #2, was irrelevant, or was already going to be covered later on in the course. As a result of Mosteller's and other educators' experience with this exercise, many have opted to narrow the questions to only "What was the muddiest point?"

Subsequent research studies have been mixed, with some qualitative studies suggesting that Classroom Assessment Techniques like the "Muddiest Point" had beneficial effects on student learning, but others (particularly quantitative studies) struggling to show a concrete effect.1 However, many teachers and students around the world have felt that these techniques did improve their learning experience, so they remain popular and I'd invite you to give the "Muddiest Point" a try in some of our lessons.


Alison has helpfully shared some advantages that she has found in using the Muddiest Point CAT for you to consider when deciding whether to give it a try in your own lesson.

Advantages include

  • Opportunity to enable students to reflect on learning
  • Chance to address misconceptions and pick up on confusions before they become entrenched
  • Teacher gets insight into consistent difficulties, which may change the way they plan future lessons on the subject
  • Takes little time
  • Most importantly, models difficulty and confusion as constructive and productive rather than ‘a bad thing’ to be embarrassed about/avoided

Alison also notes that it may be best to not do the assessments too often, as some girls may find it discouraging to focus on areas of confusion.

At G&L

With our investigation of cognitive science and its relation to learning, these CAT methods, including the "Muddiest Point," seem to mesh well with the theory of metacognition. Girls are encouraged to actively reflect upon the lesson and their learning, and write very briefly about something that they feel they need to spend more time on, and/or need more help with.

Not only does this guide girls towards actively thinking about their learning, but it provides you with potentially valuable feedback as to where the class are at and what areas you may want to devote more time / resources to.

In Practice

In order to help you try out the "Muddiest Point" classroom assessment technique, I have created some quizzes in Socrative, Nearpod, and Google Forms that you are welcome to copy.


In the closing few minutes of your lesson, ask students to turn to their iPads and open this quiz (in the relevant app). You can share it with them on the board or via Classroom. Give girls about three minutes to complete in order to give them a chance to consult their notes and consider their answers.


Basic: Only the base "Muddiest Point" question.

Scale: Added a four-point "how muddy?" scale.

Full: Mosteller's original trio of questions.


It is very important for girls to get some sort of response to the feedback they are providing in this exercise. Mosteller, a statistician, preferred to do this by charting the frequency of the points and sharing this with students, but you may find some of the following ways more effective:

  • Class e-mail or a post in Google Classroom
  • Online discussion (in Classroom or otherwise)
  • Post Q/A's - share further explanation about frequent points in manner of Mosteller's extra hand-outs (shared via Classroom)
  • Address frequently expressed muddy spots at the start of the next lesson
  • Devote a short period of class time to group discussion of top muddiest points
Mosteller, F. (1989) 'The "Muddiest Point in the Lecture" as a Feedback Device', The Journal of the Harvard-Danforth Center, April, pp.10-20 The Derek Bok Center for Teaching & Learning at Harvard University [Online]. Available at: https://bokcenter.harvard.edu/files/bokcenter/files/otl3-mosteller-muddiest.pdf (Accessed: 8 November 2017)
1 Simpson-Beck, V. (2011) 'Assessing classroom assessment techniques', Active Learning in Higher Education, 2011 12(2), pp. 125-132 Sage Journals [Online] Available at: https://www.rit.edu/academicaffairs/tls/sites/rit.edu.academicaffairs.tls/files/activelearning.pdf (Accessed: 9 November 2017)