Types of Informed Consent

Good practice: If possible, active and documented informed consent is preferred. This implies that participants must perform an action to indicate their willingness to participate in the research. This can be done by signing a form, but digital methods (e.g. ticking a box, pressing a button or clicking a link) can be acceptable alternatives. Such action should obviously be performed after the relevant information has been provided.

If you cannot document a participant’s consent right away (e.g. because you are interviewing someone by telephone), you can send such an informed consent form afterwards.

Possible risks associated with documenting informed consent: Documented informed consent may pose a risk to certain groups, as the information they provided could be linked back to them (e.g. illegal immigrants, victims of home violence, prostitutes, people engaged in criminal activities and HIV-positive employees). If standard procedures for obtaining written informed consent may be harmful to participants, rather than protecting their interests, other consent procedures may be justified, including verbal informed consent.

See also the information on our website concerning informed consent procedures

Note: In compliance with the EU General Data Protection Regulation GDPR, active consent is required if the research will involve collecting new data or the new use (including linkage) of personal data.

  • Signed/written consent

    Signed, written consent form prior to participation

  • Online consent

    Active online consent before the start of the research. For example, you upload an opening statement at the start of your online survey.

  • Oral (recorded) consent

    Oral consent prior to an interview that is recorded by audio or video

  • Passive/tacit consent

    Passive consent (opt-out) means that individuals’ consent is assumed if they do not explicitly object to participation after they have been informed about the study. In principle, passive informed consent is considered undesirable: first, because there is no way of knowing whether the relevant information has been received, and second, because participants (or their legal representatives) may have been unable to perform the action required to indicate non-consent. This can lead to infringement of personal autonomy and privacy.

    In some circumstances, however, passive informed consent may be acceptable:
    (a) if it would be extremely burdensome, either for the research participants or an intermediary organization involved, to obtain active consent from all individuals involved;
    (b) if the burden and risk of the research activities are very limited,
    (c) special care is taken to inform participants and/or their representatives of the study and the possibility to opt out,
    (d) the opt-out procedure is straightforward.
    This may be the case for situations in which the study fits within a generally accepted activity, as with research on learning performance in schools, evaluation of a service (hospital, company) or research on workflows and performance in work organizations.

    In such cases, the researcher must provide convincing evidence that: 
    1) the context and importance of the study justify passive consent and 
    2) sufficient action will be taken to inform the participants or their legal representatives (e.g. through various and repeated approaches). 

    • addition to 2): e.g., a school’s policy should ensure that parents/caretakers are regularly (e.g. once a year) informed about the possibility that students might be involved in research during teaching activities. For every research parents are informed and can withdraw participation for that particular research.  

    Note: In compliance with the EU General Data Protection Regulation GDPR, active consent is required if the research will involve collecting new data or the new use (including linkage) of personal data.

  • No Consent

    In exceptional cases, the requirement for informed consent may be eliminated. This may apply if (1) informed consent would not be in the interest of the participant; (2) the research involves observing behavior in public spaces, while no personal data are collected and no information about specific individuals can be derived from the research data; (3) the research involves examining behaviour at the group level. Please consult the relevant sections below if you think your research falls into one of these categories.

    1. When informed consent would not be in the interest of the participant: This is often the case with consent from parents or legal representatives. One particular case in which a researcher could decide not to inform the parents is when the child explicitly opts for anonymity. For example, this could occur in the context of online self-help sites. In such cases, contacting the parents would be more intrusive to the child’s privacy than not contacting them would be. In principle, the desire for anonymity should be respected, and it can be violated only in the following exceptional cases: 
    a) If failure to inform parents, healthcare professionals or authorities would clearly be contrary to the child’s interests (e.g. if the child is in urgent need of medical or psychiatric care). 
    b) If failure to inform parents, healthcare professionals or authorities would bring serious harm to others (e.g. if a child mentions having committed or intending to commit a serious crime).

    In some cases, even if the identity of the child is known, the involvement of parents or legal representatives might still be damaging to the child (e.g. in cases involving the investigation of abuse). Note that, in such cases, the gathering or use of personal data for research should be prevented, as doing so would also require parental consent.

    2. When observing behavior in public spaces (e.g. shopping streets, underground stations or university campuses), no individual consent is needed, as long as no personal data are collected and no information about specific individuals can be derived from the research data. Please note that this excludes audio-visual recordings on which people can be recognized. The investigation should also not be intrusive in other ways (e.g. involving extensive following of any one individual). What counts as intrusive is determined by the context (i.e. nature of the research, environment, and people involved).

    3. When behavioral research involves examining behavior at the group level: Examples include network studies of social interactions (including bullying) in the classroom, the effect of a teaching method on class performance or the effects of a new management technique on teamwork. In such cases, it may not be possible to obtain informed consent from every individual (and, in some cases, it could be undesirable, as it would affect the group process). In such cases, the researcher should ensure the following:

    • Informed consent must be obtained from the responsible person, institution or authority (e.g. the management of the institution or company). In the case of Dutch schools, depending on the nature of the research, consent may have to be obtained from the school’s representative advisory board, constituted in conformity with the provisions of the Education Act (Wet Medezeggenschap Onderwijs 2006, see www.infowms.nl). This applies only to research that would affect any of the points listed in Article 10 (Instemmingsbevoegdheid medezeggenschapsraad) of this law. If the research involves examining the effect of an educational, teaching or other procedure, the procedure must have been set up and implemented by the institution in question, or it must have been approved by the institution and implemented with its permission and under its supervision.
    • Individual privacy and autonomy must be preserved: no personal data may be gathered without the active consent of the individuals concerned or their legal representatives. This means that the data must also be anonymous to the researchers (i.e. it is not sufficient to separate or recode participant details).
    • Whenever possible, the relevant groups (including the parents or guardians of children used as test subjects) must be informed in advance of any interventions, procedures, and observations, unless doing so would seriously interfere with the objective of the investigation. The researcher must provide evidence of the need to withhold such information and take measures to prevent any negative consequences of withholding such information.
    • Interventions and/or procedures must occur at the group level, and they must not be aimed at specific individuals. The effects of an intervention can obviously vary from one individual to another. For example, even if a measure is applied to an entire class, the behavior of some children may change more than that of others.
    • The research results must be reported only at the group level. This also applies to reports made to the institution in which the research was performed. In this context, ‘groups’ may be sub-groups, as long as the data provided cannot be traced back to the individuals concerned.