Module 2: The Five Pieces of Evidence

The information you should get from a successful reference interview

The Result of a Successful Interview

At the conclusion of a good reference interview, you should have five pieces of evidence:

  1. Purpose
  2. Deadline
  3. Type and Amount
  4. Who
  5. Where (when pertinent)

You can use the skills from the previous pages (Listening, Open-Ended Questions, Paraphrasing, Clarifying, and Verifying) to prompt patrons for this information efficiently and effectively. You may have to ask for some of the information directly (e.g. deadline), but most of this information will come out naturally during the reference interview.

Below are explanations for each piece of evidence:


  • Some questions necessitate that you know the purpose.
    • E.g.: Material needed for a term paper on Cuba can be very different than information needed for travel to Cuba.
  • Some questions are sensitive in nature; use your judgement as to how far to probe for the purpose.


  • Is there a date after which the information is no longer useful to the patron?
    • E.g.: As soon as possible vs. a few months
  • Be sure to reiterate that the library strives to get information to patrons as soon as possible and then repeat your request for a specific time frame. A specific date is helpful for you and for a back-up reference service, if appropriate.

Type and Amount

  • How much information is needed?
  • In what form will it be most useful?


  • How knowledgeable is the patron on this subject?
  • Is the patron an expert or a beginner?
  • What information does the patron already have?
  • Is the person who needs the information the person with whom you’re interacting, or are they seeking the information on behalf of another (e.g., parent; spouse; etc.)?


  • Where did the patron hear about the requested information? (of, e.g., a new title or a person’s name)
  • What is the source?
  • What prompted the question?

Pieces of Evidence in Virtual Reference

The five pieces of evidence are also important in virtual reference. No changes are necessary for interactions with virtual patrons.

Major Point: Use your reference interviewing skills to get to the basic question and gather the five pieces of evidence.