Deception occurs when researchers purposely mislead research subjects by providing them with false information or misdirect them in some way about some aspect of the research procedure and/or purpose of the research. 

Examples include:

• Subjects are told they are working with a group of other subjects on a task; however, the other "subjects" are confederates acting as research subjects.
• Participants are told they performed poorly on a task regardless of how they actually performed.

Incomplete disclosure occurs when the researchers withhold information about some aspect of the research from the subjects. In some instances, researchers may tell subjects the general purpose of the study but do not give them enough details to reveal the entire purpose. 

Examples include:

• Subjects are told the purpose of the study is to examine how much time people spend studying for finals but they aren't told the secondary purpose which is to examine how well they performed on their finals.
• Researchers inform subjects that the study is exploring people's ability to read quickly but they do not tell subjects that a task they will complete during the research is intended to also examine their emotional responses to certain words they read.

Deception or incomplete disclosure will only be permitted when the researcher documents that an alteration of the usual informed consent requirements is justified under the criteria presented in the federal regulations (45 CFR 46.116(d)).

The IRB must find and document that:

• The research presents no more than minimal risk to subjects.
• The alteration will not adversely affect the rights and welfare of the subjects.
• The research could not practicably be carried out without the alteration. (The use of deceptive techniques must be justified by the study's prospective value and there should be no reasonable alternative method that would be equally effective.)
• Where appropriate, the subjects will be provided with additional pertinent information after participation. 

The following points will be taken into consideration by the IRB when reviewing proposed research involving the use of deception or incomplete disclosure:

• Research subjects cannot be deceived about significant aspects of the research that would affect their willingness to participate or that would cause them physical or emotional harm
• Adequate justification for the use of deception or incomplete disclosure must be included in the IRB protocol application and should describe why the research cannot be conducted without the use of deception. Further, the benefits of using deception in this research must outweigh the risks.
• Subjects should be informed about the deception or incomplete disclosure (debriefed) as soon as possible.

Federal regulations prohibit the use of deceptive techniques that places participants at "greater than minimal risk." Researchers proposing to use deception or incomplete disclosure should justify its use in the IRB protocol application by addressing the following:

• In the Deception/Incomplete Disclosure section, justify the use of deception and explain why deception is necessary to achieve the goals of the study. Explain if alternative methods not involving the use of deception were considered and why these methods are not being used.
• In the Deception/Incomplete Disclosure section, complete the explain the process that will be used to debrief subjects. Explain when subjects will be debriefed and who will debrief them. Provide copies of the debriefing statement that will be given to subjects and the script that will be used by the researchers to orally explain the study.
• In the Consent Process section, complete the required sections for a waiver or alteration of some informed consent elements. When subjects are not given complete information about the study in the consent document, the IRB must waive certain required elements of the consent process such as the inclusion of an explanation of the purpose of the research. 
• In the Risk/Benefits section, explain if use of deception is likely to cause subjects psychological discomfort (i.e. stress, loss of esteem, embarrassment) while the deception is taking place. Explain how this risk will be minimized during the research and after the research is complete (i.e. full debriefing). 

Debriefing is a crucial component of the consent process for any research involving the use of deception or incomplete disclosure. Debriefing occurs when subjects are given the full explanation of how and why subjects were deceived and the true hypotheses being tested by the research. The debriefing also should include any other relevant information pertaining to the study. 

When debriefing will occur, researchers should should consider if it would be more appropriate to provide subjects with a debriefing script and/or a debriefing statement. Researchers use a debriefing script as a reference to orally explain the study to a subject. A debriefing statement is a document given to subjects to keep after an oral debriefing occurs or is made available to subjects after the research has concluded.

In some circumstances, informing subjects of deception may cause more than the deception itself. For example, if a student is selected for participation in a study based upon certain physical characteristics (i.e. weight), it may not be appropriate for the debriefing to describe that aspect of the research.

The timing of the debriefing is also important to consider depending on the nature of the research. The IRB generally requires that subjects be debriefed immediately following their participation in the research. However, it is possible that debriefing subjects immediately after their participation in the research has ended could compromise the validity of the study (e.g. subjects who have already participated in the study tell other potential subjects about the research). Therefore, the IRB recommends the following strategies:

• If the subjects' name and contact information are collected as part of the research procedures, debriefing information can be sent to them via mail, email, or by phone following the completion of the study.
• If the subjects' names and contact information are not collected, researchers can give subjects a URL (website address) that they can go to in order to view debriefing information and a date in which it is available.