Peer Instruction & Think-pair-share

Through PI, students realize that trying to articulate their position with other students, and having those students disagree and articulate their reasoning back to them, can be a powerful learning experience.

Quote from Ken Ragan, McGill University

What is it?

Peer instruction is an instructional strategy that encourages students to verbalize their answer and selection rationale, actively listen to their peer’s rationale, and critically compare / contrast their explanations with those of others. Students are presented with multiple-choice questions testing their conceptual understanding. They select an answer and communicate their choice (i.e., vote). This can involve any of the following tools: response device (often referred to as clickers), flash cards, or discreet hand signals. The tabulated responses enable the instructor to determine the next pedagogical move in real-time (i.e., in accordance to student understanding). If a significant proportion of students select an incorrect response, they are given the opportunity to debate/discuss their answers with a peer(s) before re-voting. Following the second vote, the instructor presents the correct response and makes any necessary clarifications.

Essential features for successful implementation of this strategy: (1) Conceptual questions: Selecting multiple-choice questions that tap into students’ understanding of concepts that are often misunderstood initially (i.e., student’s prior knowledge may be erroneous or may not be consistent with the manner in which a particular discipline understands the concept). (2) Peer discussion: Providing time for peer-to-peer discussion. This discussion is most effective when peers with different answers (i.e., views, understanding, etc.) talk and explain to each other.

Purpose: This strategy supports conceptual learning. Often, students who came to the wrong conclusion in the first vote, are able to answer the question correctly on the second vote through this process of discussion and debate with peers.

Note: Peer Instruction is similar to Think-pair-share. However, though Think-pair-share follows three major steps of peer instruction it tends to be less formal, requiring less preparation by an instructor to implement. With Think-pair-share, students are given a question or problem to solve. The instructor allows them a few minutes to think about the problem alone (think), then has students group together (pair) and discuss to compare and elaborate on their thinking (share). This can be followed up with a whole class share – especially for more complex content. This strategy can be an effective way to break up a lecture by enabling students to engage with course content, discuss with their peers and share knowledge.

Skills Promoted

Communication
Conceptual reasoning
Evaluative reasoning
Metacognition

Who's using it?

SALTISE community members who use this strategy and are willing to share advice and/or resources.

Institution	Discipline	Instructor	Classroom settings
McGill University Level: University	Engineering	Marta Cerruti	Traditional Classroom Classroom size: 100 View resources used
McGill University Level: University	Engineering - Ethics	Lawrence R. Chen	Traditional Classroom Classroom size: 200 View resources used
McGill University Level: University	Engineering	Lawrence R. Chen	Traditional Classroom Classroom size: 200 View resources used
University of Guelph Level: University	Social Sciences	Rachael Marshall	Traditional Classroom Classroom size: 20-40 View resources used
McGill University Level: University	Engineering	Chris Moraes	Traditional Classroom Classroom size: 75-95 View resources used
McGill University Level: University	Physics	Kenneth Ragan	Lecture hall (auditorium) Classroom size: 450 View resources used
Marianopolis College Level: College	Physics		Classroom with whiteboards Classroom size: 30-40 View resources used

Institution	McGill University Level: University	McGill University Level: University	McGill University Level: University	University of Guelph Level: University	McGill University Level: University	McGill University Level: University	Marianopolis College Level: College
Discipline	Engineering	Engineering - Ethics	Engineering	Social Sciences	Engineering	Physics	Physics
Instructor	Marta Cerruti	Lawrence R. Chen	Lawrence R. Chen	Rachael Marshall	Chris Moraes	Kenneth Ragan
Classroom settings	Traditional Classroom Classroom size: 100 View resources used	Traditional Classroom Classroom size: 200 View resources used	Traditional Classroom Classroom size: 200 View resources used	Traditional Classroom Classroom size: 20-40 View resources used	Traditional Classroom Classroom size: 75-95 View resources used	Lecture hall (auditorium) Classroom size: 450 View resources used	Classroom with whiteboards Classroom size: 30-40 View resources used

Why use it?

Kenneth Ragan

McGill University, Montreal

Benefits

Overall, PI allows students to look at the problem in a different light through critical evaluation of peer discussions. When students actively listen to one another during PI, there is always clear motion towards the right answer. Consider the PI example provided in Figure 1a below. While only approximately 32% of students were able to come to the correct answer on their own (Figure 1b), following the PI process, 78% of students (Figure 1c) came to the correct conclusion.

One of the powerful aspects of PI is that students realize that some problems are not as easy as they originally thought. After the students vote on the problem, there is a moment of silence before the results of the vote are presented. Prior to seeing these results, students collectively feel they aced the problem. Nonetheless, the voting often exhibits a three way split between possible answers. Consequently at least two-thirds of the students wind up realizing ‘maybe the problem is not as obvious as I thought’. Students must then ask themselves where they went wrong. The instructor can sense them becoming engaged through discussion. When students vote for the second time, there is dead silence in the room as they are wondering how everyone did and if they are moving towards the right solution. This is what makes PI an effective strategy.

I am increasingly encouraging my students to form PI-based study groups outside the classroom.

Challenges

As with all strategies, PI only goes so far. An instructor will rarely observe over 80% of students answering a conceptual question correctly, even with the PI process. In Figure 1, we observe that 32 percent of students still struggled with the sample question presented following PI. When student responses are spread, the instructor can sense that some students are going down the wrong path collectively (especially when students have deeply held misconceptions). Furthermore, no amount of instruction among peers will bring them to the correct answer. Thus, following the PI process, the instructor must intervene and guide the discussion in the right direction, allowing students to examine the problem in a different way. This is where a different strategy may be needed.

Ready to try it out?

This version of Peer Instruction (PI) is a six step instructional process. Other iterations of this process are possible depending on the pedagogical needs.

STEP 1: Instructor provides students with content (e.g., mini-lecture, pre-class reading).

STEP 2: Instructor prepares multiple choice questions/problems.

BEST PRACTICES NOTE: Concept-based questions are the most effective to promote student debate and discussion of understanding).

STEP 3: Individually, students answer the question and enter their vote using a polling method or device (e.g., clickers or phone app).

BEST PRACTICES NOTE: maintain anonymity of choice even when polling does not use technology See document for options.

IF less than 35% answer correctly:

STEP 4 : Instructor revisits the concepts required to answer the question.

IF between 35-70% answer correctly:

STEP 5: Students, in pairs or small groups, discuss their answers and explain their reasoning.

BEST PRACTICES NOTE: pairs or groups should consist of individuals holding different opinions, or playing the skeptic and arguing for an alternative answer.

STEP 6: Individually, students vote again and select answer based on discussion – they can either keep their original answer or change.

IF more than 70% answer correctly:

STEP 7: Instructor briefly reviews the concepts.

STEP 8: Instructor begins presenting material relating to the next topic.