The opening cold call is one of the most recognizable hallmarks of case teaching at HBS. After framing the class session, the instructor typically cold calls a student to open the discussion. Some instructors use additional cold calls during the class.

Why Cold Call?

Cold calling has three key objectives:

  • Establish and reinforce high expectations for student preparation
  • Provide a developmental opportunity for the opening student with respect to content mastery, critical thinking, and communication skills
  • Catalyze the discussion and serve as a touch point throughout the class session

Cold calls should not be viewed as punitive. Instructors can frame cold calls as "opportunities to shine" and further encourage this view by balancing challenge and support as the cold call unfolds.

Whom to Call

Instructors may take different approaches to selecting a student for the cold call, depending on pedagogical objectives and the nature of the case.

Options include:

  • Non-expert: An instructor may call on a student with less expertise in the subject matter to prevent the discussion from moving ahead too quickly or becoming too complex.
  • Expert: An instructor may call on a subject-matter expert or a relatively strong student to set high standards for cold call quality. When the case is especially complicated, an instructor may call on an expert to help explain or clarify difficult concepts to the section.
  • Student with background related to the case: An instructor may, for example, call on a student from the same geographic region as the company in the case or a graduate of the same school as the case protagonist. This approach can be used to lighten the mood or add humor to the cold call as opposed to drawing on expert knowledge per se. 
  • Eager, well-prepared student: A instructor may select a student who has demonstrated strong preparation and enthusiasm to contribute, but who may not have been called on for several classes. This approach provides an opportunity for the student to shine and signals respect for the student's past engagement and quality of participation. 
  • Low frequency participant: As the term progresses, an instructor may use cold calls to engage and develop students who have participated with below average frequency in class discussions. This strategy should be used with caution, since it may make cold calls more predictable or lead them to seem punitive.
  • Randomly selected student: An instructor may randomly select a student to open with the aim of making the choice unpredictable and discouraging the notion that students who participate frequently are "immune" from cold calls.  

Students may find cold calls to be both anxiety-provoking and inspiring. Regardless of the strategy used for selecting the opener, instructors should position the call as a challenging but fair opportunity for students to experience personal development and contribute to the section's collective learning.

Managing the Exchange

Cold calls can vary in terms of intensity and length across classes and instructors. This section discusses factors that may influence how "cold" and how long the instructor chooses to make the opening call.

How "cold"?

The "temperature" of an opening question ranges from "cold" to "warm" depending on how much notice the student receives before having to respond. The less notice, the more challenging the call is likely to be, due to the surprise factor.

  • No notice: Asking a student to respond immediately to the opening question represents the "coldest" form of the cold call. This approach is especially cold when the opening question is not one of the assignment questions.
  • Short notice: An instructor may give the opener notice during the class introduction in order to provide a few moments for the student to collect his or her thoughts.
  • Advance notice: Less commonly, an instructor may contact the opener right before class or outside of class (e.g., via e-mail, office hours). This approach -- usually referred to as a "warm call" -- provides the student with additional time to prepare and reduces the likelihood that the cold call will get off to a rocky start.

How long?

A typical cold call can last several minutes but may go longer based on the instructor's cold calling philosophy and the opening student's level of preparation. Instructors must balance the objective of creating a substantive exchange with the student and the competing goal of bringing other voices into the discussion.

Sample Opening Questions

The opening question can serve as a touch point throughout the class, and thus the question should be substantive and engaging to support an extended discussion. Below are examples of questions soliciting action, evaluation, diagnosis, and description for four hypothetical cases. Instructors should be cautious about the use of descriptive questions since these tend to be less engaging when solely used to solicit case facts.

An apparel company considers major plant improvements to increase productivity…

Action: Should the board approve funding of the plant improvement plan? Why or why not?

Evaluation: Will the proposed plant improvements solve the company’s problems? Why or why not?

Diagnosis: Why has output declined at the plant over the past year?

Description: Walk us though the production facility—how is it organized?

A CEO confronts a lack of financial resources to support the company’s aggressive growth strategy…

Action: As [the protagonist], what is your action plan for dealing with the current impasse?

Evaluation: What grade would you give to the CEO and why?

Diagnosis: What factors led to the situation that [the protagonist] is facing at the time of the case?

Description: What dilemma is [the protagonist] confronting at the time of the case?

A company considers an acquisition that would expand its market share…

Action: As a director on [Company A’s] board, would you approve the acquisition? Why or why not?

Evaluation: Considering the industry's state, is this a good time to think about acquiring [Company B]?

Diagnosis: How would the acquisition affect [Company A’s] competiveness in the industry?

Description: How is [Company A] thinking about financing the proposed acquisition?

A case presents different viewpoints on the causes of the Great Depression…

Action: What should the Federal Reserve have done in October 1929 following the market crash? 

Evaluation: Which theory of the causes of the Great Depression is most compelling to you and why? 

Diagnosis: Why did the Great Depression become a depression and not remain a recession? 

Description: How would a Keynesian economist explain the Great Depression?


How and how often to intervene with a follow-up probe, a question of clarification or echo of a substantive point is situational and subjective. In general, the instructor should engage the student with some follow-up. A lack of follow-up can be ambiguous and may signal to the class that the opener's response was weak or that the instructor is not inclined to challenge students.

Reasons to stay with the student

  • Advancing the discussion: The student is well prepared and the comments are helpful in mapping out topics important to the learning objectives.
  • Providing a developmental opportunity: The instructor wants to foster the student’s ability to respond to difficult questions in real time, even if the student is struggling.
  • Signaling accountability: The instructor wants to encourage strong preparation, discourage shallow “chip shots,” and emphasize that students play a vital role in advancing the learning.

Reasons to move on to another student

  • Receiving a satisfactory response: The student has laid out a cohesive answer, and the instructor has sufficiently probed the underlying rationale.
  • Bringing in other voices: The student has clearly articulated a position and the instructor wants to open up the discussion to allow other students to critique, support, or offer alternatives to the analysis.
  • Providing assistance or setting up a debate: The instructor may call on other students to offer help to the opener, surface an alternative viewpoint, or solicit questions from classmates. The instructor can then either re-engage the opening student or move on with the discussion.
  • Reaching diminishing returns: While it can be helpful, developmentally, to stay with a struggling student, it may be best to move gracefully to another student when the call unfolds poorly (e.g. when a student is clearly unprepared).

The Christensen Center’s Questions for Class Discussions tip sheet provides suggestions on follow-up probes after an opening question.