Guidance on Use of Deception and Incomplete Disclosure in Research

The purpose of this document is to assist researchers in addressing issues related to using deception in research with human subjects[1].

Central to the ethical standards governing the participation of human subjects in research is the notion of respect for persons.  This principle demands that subjects enter into the research voluntarily and with adequate information[2]. When deceptive methodologies are used, participants are given incomplete or misleading information about what to expect during the study activities which compromises their ability to give fully informed consent.  Ordinarily, research proposals failing to adhere to the principle of respect for persons by compromising the consent process would not be approved.  However, in unique circumstances where the study design requires omission of details that might alter the subject’s responses that are being investigated, vital information about the study or study activities can be withheld from subjects until after their participation. 

Deception and incomplete disclosure can be valuable research methods and studies involving the use of deception have resulted in significant contributions to science. However, the use of deceptive methodologies places a special burden of responsibility on researchers to provide scientific justification for the deception. Researchers must also provide the appropriate additional safeguards, beyond those safeguards normally in place, to protect the rights and welfare of participants. Researchers are urged to explore the literature within and outside of their field in order to fully understand the history and critical issues related to deceptive methods.


Deception is when a researcher gives false information to subjects or intentionally misleads them about some key aspect of the research. This could include feedback to subjects that involves creating false beliefs about oneself, one’s relationship, or manipulation of one’s self-concept. Incomplete Disclosure is a type of deception that involves withholding some information about the real purpose of the study, or the nature of the research procedures[3].

The guidance provided here applies to both deception and incomplete disclosure.

Examples of Deception:

Subjects complete a quiz, and are falsely told that they did very poorly, regardless of their actual performance.[4]

The study includes a researcher’s “confederate” (an individual who poses as a subject) but whose behavior in the study is actually part of the researcher’s experimental design. [5]

Example of Incomplete Disclosure:

Subjects are asked to take a quiz for research but they are not told that the research question involves how background noise affects their ability to concentrate.[6]

Participants are asked to read a list of words or view a series of images but are not told that their memory will be tested.

The use of deception has been historically complex and therefore warrants special consideration and additional safeguards. Milgram’s (1974) study of obedience, Zimbardo’s (1973) prison study, and Humphrey’s (1975) “tearoom” observations are reminders of the risks associated with the use of deception in social and behavioral research. These studies highlighted not only the risks related to the use of deception, but also the potential for the use of deception or incomplete disclosure to undermine public trust in the research enterprise. Researchers should be cognizant of discipline-specific standards when preparing to engage in research using deceptive methods. The American Psychological Association provides one such set of standards for researchers.

American Psychological Association standards for use of deception

8.07 Deception in Research[7]

a) Psychologists do not conduct a study involving deception unless they have determined that the use of deceptive techniques is justified by the study's significant prospective scientific, educational or applied value and that effective nondeceptive alternative procedures are not feasible.

b) Psychologists do not deceive prospective participants about research that is reasonably expected to cause physical pain or severe emotional distress.

c) Psychologists explain any deception that is an integral feature of the design and conduct of an experiment to participants as early as is feasible, preferably at the conclusion of their participation, but no later than at the conclusion of the data collection, and permit participants to withdraw their data.

Points for Consideration

Protocols that include the use of deception should demonstrate that the investigators are aware of, seeking to minimize, and have a plan to address the possible negative impacts on participants, such as:

  • Potential of deception to facilitate unwanted and inappropriate invasion of privacy
  • Potential coercion of participants into acting against their own will
  • Potential for participants to change their mind about the use of their data after the deception is revealed
  • Damage to a participant’s self-esteem through feeling ashamed, guilty, stressed, embarrassed, feeling manipulated, or lacking control over their own experience
  • Feeling forced to have knowledge about one’s self that otherwise one might not want to know (sometimes called inflicted insight)[8]
  • Creation of suspicion and/or distrust in the investigator and/or a generalized distrust of the broader research enterprise.

Protocols that include the use of deception should justify the use of this method and demonstrate that risks to subjects will be minimized by using procedures that are consistent with sound research design[9] including:

  • The study must not involve more than minimal risk to the subjects
  • The use of deceptive methods must be justified by the study’s significant prospective scientific, educational, or applied value
  • The protocol must clearly address why deception or incomplete disclosure are necessary to ensure the research is scientifically valid and feasible and that an alternative, non-deceptive methodology could not be used
  • Subjects should not be deceived about any aspect of the study that would affect their willingness to participate

Informed consent

Deception and incomplete disclosure may interfere with the ability of the research subject to make a fully informed decision about whether or not to participate in the research.  In general, deception is not acceptable if, in the judgment of the IRB, the participant may have declined to participate had they been informed of the true purpose of the research. Research using deceptive methods involves omitting one or more of the required elements of consent; usually all or part of the true study purpose and the risk of the deception itself.  The IRB may approve a consent procedure that does not include, or which alters, some or all of the elements of informed consent, or waive the requirements to obtain informed consent provided the IRB finds that[10]:

  • The research involves no more than minimal risk to the subjects;
  • The waiver or alteration will not adversely affect the rights and welfare of the subjects;
  • The research could not practicably be carried out without the waiver or alteration; and
  • Whenever possible, the subjects will be provided with additional pertinent information after participation (a complete debriefing).

When appropriate, researchers are encouraged to consider the use of a prospective consent process that informs participants that a study will not be described accurately or that some procedures will be deceptive and provides them an opportunity to decide whether or not to participate on these terms. Below is sample language for consent forms:

For scientific reasons, this consent form does not include all of the information about the research question being tested. The researchers will give you more information when your participation in the study is over.

Debriefing and Dehoaxing


Debriefing is a process that can be undertaken at the conclusion of any research activities, regardless of the whether deception is part of the research design. It is appropriate to provide participants with a simple, clear, and informative explanation of the experiment’s purpose and the methods that were used, as well as bibliographical citations advising them where they can obtain additional information on the subject being studied.[11]

The content and extent of a debriefing should align with the details and risks of the study. If the study involves deception, a plan for effective and respectful debriefing and dehoaxing is critical to minimizing risks. The process should be conducted by researchers who are qualified to approach the debriefing in a manner that supports subjects in expressing any thoughts or feelings they may have about being deceived and can be appropriately responsive to their reactions. The APA outlines three basic requirements for debriefing.

American Psychological Association standards for use of deception

8.08 Debriefing[12]

a) [Researchers] provide a prompt opportunity for participants to obtain appropriate information about the nature, results, and conclusions of the research, and they take reasonable steps to correct any misconceptions that participants may have of which the [researchers] are aware.

b) If scientific or humane values justify delaying or withholding this information, [researchers] take reasonable measures to reduce the risk of harm.

c) When [researchers] become aware that research procedures have harmed a participant, they take reasonable steps to minimize the harm.

Debriefing sessions should mitigate the potential harm of deception by explaining the rationale for the deception.  Participants should be given a clear and informative explanation for the design of the study and the methods used, and they should have the opportunity to ask questions.[13]


Dehoaxing is the process of convincing subjects who have been deceived as part of a research study that they have in fact been deceived.

The purpose of dehoaxing is to prevent possible future harm to the subject. For example, subjects may be given false pretest scores in order to test the effect of these scores on subsequent tests of motivation levels. If subjects believe that the false scores represent their true abilities, their level of self-esteem may become jeopardized. In cases such as these, simply informing the subjects that they were deceived and that the pretest scores were false may not be sufficient. In addition to informing the subjects, some form of demonstration may be needed to convince subjects that they were deceived and thereby diminish the undesirable effects of the study[14].

Goals of Dehoaxing

  • To repair the breach of informed consent created by the deception
  • To remove any confusion or defuse any tensions that might have been generated by the deception
  • To repair any breach of trust that has occurred not only between investigator and subject, and preserve the public’s trust in research endeavors
  • Dehoax with dignity and an unconditional positive regard for the range of emotions subjects may experience in response to the deception.
  • To convince the subject the behavior was due to situational determinants within the experiment rather than to dispositional determinants within the subject.[15] This is also referred to as desensitization.

Continuous Debriefing

Since subjects may feel a range of emotions at different intervals about being deceived, a process for continuous or staged debriefing may be needed; however, this is usually only done for greater than minimal risk studies

Delayed Debriefing

If a study requiring debriefing will run over several days or weeks, subjects who have completed the study might tell others about it. If they have been debriefed and thus know the real purpose of the study activities, they might share that information with prospective subjects, thus compromising the scientific validity of the study. Under these circumstances, the IRB may consider a delayed debriefing based upon the level of risk to subjects and the justification for delay. There are several strategies to handle a delayed debriefing. Provided that the delay is not extensive and an in-person debriefing is not necessary to assess and address potential harms, debriefing information can be sent via e-mail or mail. The IRB will consider the length of a proposed delay in relation to the other study details. If names and contact information are not collected, researchers could:

Give subjects a URL where they can get debriefing information after a particular date upon which the information will be available.

Have each subject self-address an envelope before they leave the study session for the purpose of receiving post-study (debriefing) information.[16]

Note that as the risks related to the study increase, the delay between the conclusion of a subject’s participation and the debriefing should decrease because the potential harms related to the deception could be magnified over time. Depending on the details of the study and the level of risk, an immediate in-person debriefing may be necessary to minimize risk, even if it jeopardizes future enrollment.


There are certain circumstances under which the IRB may waive the requirement for debriefing when a study involves deception, such as when the debriefing regarding deception may cause more harm than the deception itself. For example, if a student is selected for participation in a study about group behavior based on previously measured “negative” behavior or characteristics, it might not be appropriate for the debriefing to describe the selection process.[17]

Protocol Preparation

The protocol and related documents submitted to the IRB for review must include the following:

  • Description of the manner of deception and how the deception will take place
  • Explanation of why deception is necessary to the protocol
  • Description of whether deception results in increased risk
  • A description of any previous use of deception in similar research and a summary of any actual harms or reactions from participants to the use of deception
  • A description of alternatives to deception that were considered and an explanation as to why these alternatives were rejected
  • Indication of whether deception would impact a participant’s willingness to participate
  • Consent process and document that meets the requirement for waiver of one or more elements of consent 45CFR46.116
  • Description of post study debriefing that includes offering the participant the option to withdraw their data from the study
    • If an exception to this requirement is requested the study must be reviewed by the Full Board
    • Debriefing form or script
    • Members must have adequate training to minimize subject’s distress or acquire outside experts to provide needed resources.  Qualifications of the person providing debriefing should be commensurate with the level of potential risk to the subject. 

Review Level

Research involving deception could fall into any of the three review levels (exempt, expedited, or full board) depending on the specifics of the study. Studies involving deception are not eligible for exempt category 1 (research conducted in established or commonly accepted educational settings) because deception is not a “normal educational practice.” However, these studies may be eligible for exempt category 3 if they do not involve risk or a plan to enroll children and include informing the participants that they will be unaware or misled regarding the nature or purpose of the research.

SAMPLE Debriefing Language

Adapted from UC Berkeley[18]

Our research actually focuses on the development of "status hierarchies" in small groups. In many small groups such as project teams, ad hoc committees, or juries, some people tend to "take charge" more than others. However, the process by which these small group hierarchies develop is not well understood. In this study, we are attempting to understand what happens when two members of a group disagree as to who should take charge.  To try and obtain unbiased or natural reactions, we had to give you some false information at the beginning of the study. We informed you that, based on your scores on the tests from the prescreening packet, we had determined that you were the most suited to lead the group in the group task, and we told you that you were the only member in the group who received this information. But in fact, we gave this same information to one other group member, i.e., we also told this group member that he or she was the person best suited to lead the group. Thus, each of you was under the impression that you were uniquely suited to lead the group.  This was necessary for us to better understand how status disagreements proceed and how they are resolved.  By telling two of you that you were each best suited to lead the group, it was much more likely that a status disagreement would emerge. Without telling two of you, it was more likely that only one person would attempt to "take charge," and thus no status disagreement would occur. We apologize for misleading you, but we believe this was the only way to examine the processes that are the object of our research. In designing this study, we took care to minimize any possible risks or discomforts that might be related to the deception.

Now that you understand the true nature of our study, you have the chance to refuse the use of the data we collected from you for research purposes. You are free to ask us not to use your data in our study analysis. If you decline to let us use your data, you will still receive the $15 payment just as you would if we use your data in our analysis. This is entirely voluntary, but we hope to analyze as much data as possible to better understand the processes by which status hierarchies develop in groups.

Because this experiment is ongoing, we request that you not share the true nature and purpose of this experiment with others who might potentially participate in our study.


[1] This document borrows heavily from guidance developed by other academic institutions and established professional codes and standards.

[7] American Psychological Association,

[8] Baumrind D. Research using intentional deception. American Psychologist 1985; 40:165–74.

[9] 45 CFR §46.111(a)(1) Criteria for IRB approval of research.

[10] 45 CFR §46.116(c) General requirements for informed consent.

[11] University of South Carolina,

[12] American Psychological Association,

[15] Holmes D, Debriefing After Psychological Experiments II. Effectiveness of Postexperimental Desensitizing, American Psychologist December, 1976; 31(12): 868

[16] University of South Carolina,

[18] University of California, Berkeley