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Some research studies may require the withholding of information from participants or the deception of participants by providing false or misleading information.  While these may be effective tools for the conduct of certain types of research, they also raise ethical concerns regarding participants’ rights and pose regulatory challenges regarding informed consent requirements.

This guidance aims to help researchers understand what deception and incomplete disclosure mean in research, when they can be used, important points to consider, and how to properly debrief participants afterward.

Deception studies: Intentionally provide misleading or false information to participants.

Examples include:

  • Participants complete a quiz and are told that they did poorly, regardless of their performance.
  • Participants are told that that they will be engaged in a cooperative task with other participants to earn points that have monetary value, but instead participants will be interacting with study personnel who ensure their efforts are not successful.
  • A study enrolls participants with anxiety and tells them to expect moderate pain during a procedure, but no painful procedures are administered.

Incomplete disclosure: Withholding information about the true purpose or nature of the research to participants.

Examples include:

  • Participants are asked to take a timed test, but they are not told the research question that involves how background noise affects their ability to concentrate.
  • Participants are told they are completing a questionnaire to evaluate statements about their memories of growing up, but they are not told that the statements shown to them will be based on their demographic and are intended to induce an emotional response, which will be tracked. Back to top

Investigator Responsibilities
Informed Consent Process
Debriefing Requirements
Debriefing Timing
IRB Review
References and Resources

Investigator Responsibilities

When conducting research involving deception or incomplete disclosure, investigators must ensure the research follows their discipline’s professional ethics. They must describe the consent and debriefing process, as well as the risk/benefit ratio analysis in the submission.

The IRB application must:

  • Justify why deception or withholding information is necessary.
  • Explain why alternatives are not feasible.
  • Describe how the potential benefits justify the deception.
  • Address any potential psychological discomfort for participants and how it will be minimized during and after the experiment.
  • Outline the debriefing process, including when, how, and by whom participants will be informed, and include a copy of the debriefing script.
  • Request a Waiver or Alteration of Informed Consent if participants are not given complete information in the consent document. The IRB must determine if the research qualifies for this waiver or alteration.
    • Note that FDA-regulated research does not allow waiver or alteration of consent for deception or incomplete disclosure. Back to top

Informed Consent Process

Researchers should consider disclosing to participants that the study involves withholding information or deception during the consent process. If a disclosure during the consent process will not be provided, the researchers must justify this omission.

Sample Language for Consent Materials:

  • The purpose of this study is [describe purpose]. Not all study details have been explained. We will fully explain the research after all participants finish the study.
  • We have described the general nature of what you will do, but the full intent of the study will be explained after [your participation OR all participants complete the study]. At that time, we will provide more information and answer your questions.
  • Due to the nature of the study, we cannot disclose the study purpose at this time. However, we will hold a debriefing session to answer questions and explain the study after your participation. Back to top

Debriefing Requirements

Researchers must debrief participants at the end of their participation unless there’s a valid reason why debriefing can’t be done. The debriefing should explain the study’s hypothesis, the deception used, why it was necessary, and other relevant information.

The IRB may require that participants have the option to withdraw their data from the study after learning the true nature of the research, especially if the study collects sensitive information.

Debriefing may not be appropriate if it could cause more harm than the deception itself. The IRB and the investigator will decide whether participants should be debriefed after unknowingly or knowingly participating in deceptive research. For example, if a student is chosen based on physical traits like weight or perceived unattractiveness, it might not be appropriate to mention this in the debriefing. Back to top


Debriefing Timing

Participants should be debriefed right after their participation. However, if immediate debriefing could affect the study’s results because participants might share information with others, the consent form must state that debriefing will happen after the study is complete. The consent section must also explain why delayed debriefing is necessary.

The following strategies can be used to manage such situations:

  • If participant names and contact information are collected as part of study procedures, debriefing information can be sent when the study is completed via mail, email or by phone.
  • If participant names and contact information are not collected researchers can:
  • Give participants a URL where they can get debriefing information and a date upon which it will be available.
  • Have each participant address an envelope to himself/herself before leaving the study session. Then send mail the debriefing information when the research is completed. Back to top

IRB Review

The 2018 Revised Common Rule allows deception to be approved as Exempt research if participants agree in advance to be misled about the study’s nature or purpose, and the research fits into Exempt categories. Studies with incomplete disclosure can also be exempt if they qualify for the Exempt categories. If the investigator doesn’t disclose the deception in the consent, the IRB review level will be Expedited.

The IRB cannot approve research in which participants are deceived about a component of the study that poses more than minimal risk or would likely otherwise affect their decision to participate.

When reviewing research that involves deception or incomplete disclosure, the IRB must evaluate the above information and consider the following:

  • The scientific value and validity of the research
  • Alternative procedures
  • The certainty that deception does not extend to influence participants’ willingness to participate
  • The possibility of experimentally induced harm and the ability of the proposed procedures to remove such harm through debriefing
  • The potential of deception to facilitate unwanted and inappropriate invasions of privacy
  • Whether the researcher has the skill and resources to minimize potential distress or anger
  • Whether a waiver or alteration of consent is justified
  • Debriefing process and debriefing form

The IRB may require that participants are given the option to withdraw their data from the study after they learn the true purpose of the research. Back to top


References and Resources

Related Materials

Version Dates:

  • 4/16/2025: Guidance created

 AAHRPP Element:  

  • II.3.G.

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