01 · The Question
Should participants sign paper, agree verbally, or consent electronically?
Consent used to evoke a fairly predictable image: a researcher and participant sitting together with a paper form and a pen.
Research no longer happens only in that setting. Participants may join studies remotely, complete online questionnaires, use research apps, attend video calls, or live far from the research team. Some studies may also have good reasons not to collect signatures at all.
This creates a practical question: should consent be written, verbal, or electronic?
The answer depends less on which format seems most modern or convenient and more on whether the method adequately supports informed decision-making and satisfies the requirements governing the study.
03 · What You Need to Know
Choosing a consent method that fits the research
Written, verbal, and electronic consent are sometimes discussed as though researchers simply choose one of three competing formats. In practice, the categories can overlap.
A researcher might send an electronic information sheet, discuss it verbally by video call, answer questions, and obtain an electronic signature. Another study might provide a paper information sheet but obtain verbal agreement under an approved waiver of signed documentation.
The better question is therefore not merely "Which format am I using?" but "How will participants receive information, interact with the research team, express their decision, and how will that decision be documented?"
Written consent creates a durable physical record
Traditional written consent usually involves providing the participant with a paper consent document and obtaining a handwritten signature when required.
This approach is familiar, easy to conceptualize, and appropriate for many in-person studies. The document can present substantial information in a stable format that participants can review and retain.
Written consent can also create a clear documentation trail showing which version of the consent form was signed and when.
Potential Advantages
- Provides a tangible record of the consent information and agreement.
- Allows participants to read and revisit information at their own pace.
- Is familiar to researchers, ethics committees, and many participants.
- Can be practical when participants and researchers meet in person.
Potential Limitations
- A signature can encourage researchers to mistake documentation for understanding.
- Paper can be inconvenient for remote or geographically dispersed participants.
- Signed forms may create identifiable records that require secure storage.
- Text-heavy documents may be difficult for some participants to use effectively.
Written consent works best when the document is treated as part of a communication process rather than a contract silently placed in front of the participant.
Verbal consent can support direct interaction
Verbal consent generally involves communicating the necessary information orally and obtaining the participant's spoken agreement. It may be conducted in person, by telephone, through a video call, or through another approved communication method.
This approach can allow immediate questions and clarification. It may also be appropriate in some research where collecting a signed form is unnecessary or creates an additional confidentiality concern.
But verbal consent does not mean informal consent.
The researcher may still need an approved script, written participant information, a witness, documentation in the study record, or another procedure required by the governing framework.
Potential Advantages
- Allows real-time questions and clarification.
- Can be useful when participants and researchers are not physically together.
- May avoid creating an unnecessary signed identifier when appropriately authorized.
- Can complement written information rather than replace it.
Potential Limitations
- The researcher may need an additional mechanism to establish what information was provided and that agreement occurred.
- Participants may have less opportunity to revisit information unless written or electronic materials are also provided.
- Researcher delivery can vary unless the process is appropriately standardized.
- Verbal consent may not satisfy documentation requirements for some research.
If signed documentation would otherwise be required, researchers should not simply substitute verbal agreement. An appropriate procedure allowing consent without a signature must apply.
Electronic consent is more than putting a PDF online
Electronic informed consent, often called e-consent or eIC, uses electronic systems or processes to provide consent information and obtain or document a participant's decision.
Joint FDA and OHRP guidance describes electronic informed consent broadly. It may use text, graphics, audio, video, interactive websites, and other electronic media to convey study information and obtain and document consent.
This means e-consent can potentially do things paper cannot. A system might explain an unfamiliar procedure with animation, provide optional definitions, present information in stages, include comprehension prompts, allow participants to review sections again, and connect them with research staff for questions.
It can also be much less sophisticated. A digital consent form with an electronic signature is still electronic consent even without multimedia bells and whistles. The ethics committee will probably survive.
Potential Advantages
- Can support remote participation and geographically distributed studies.
- Can combine text with audio, video, graphics, or interactive features.
- Can automate version control, timestamps, and parts of the documentation workflow.
- Can allow participants to review information on their own device and, when designed appropriately, at their own pace.
Potential Limitations
- Digital access and digital literacy may differ among participants.
- Identity verification and electronic-signature requirements can create additional design questions.
- Poor interface design can make important information easier to skip rather than easier to understand.
- Privacy, security, system reliability, and record retention require attention.
Electronic consent still needs human interaction when participants need it
One misconception about e-consent is that technology replaces the researcher.
Joint FDA and OHRP guidance emphasizes that electronic informed-consent procedures should allow participants to ask questions and receive answers before signing when applicable. Depending on the study, this interaction may occur in person, by telephone, through video conferencing, through live chat, or using another method.
A well-designed digital interface can support communication. It should not become a technological barrier between participants and the clarification they need.
An electronic signature is not the same thing as electronic informed consent
These concepts overlap but should not be collapsed.
Electronic informed consent
An electronic process used to present consent information and obtain or document the participant's decision.
Electronic signature
An electronic method used to sign or authenticate a consent record when a signature is required.
An electronic consent process may include an electronic signature, but the signature is only one part of the process.
Under HHS-regulated research, OHRP permits electronic signatures when they are legally valid in the jurisdiction where the research is conducted. FDA-regulated clinical investigations can also be subject to requirements concerning electronic records and signatures under 21 CFR Part 11.
Researchers should therefore verify the rules that apply to their specific study and electronic system.
Paper and electronic methods can be combined
Researchers do not always need to commit permanently to one medium.
Joint FDA and OHRP guidance recognizes flexibility in using electronic and paper informed-consent methods independently or in combination throughout a study.
A participant might initially consent electronically but later receive an important amendment on paper. Another participant might review electronic materials and then discuss the study verbally before providing an electronic signature.
Hybrid consent can be useful when it solves an actual participant or operational need rather than merely making the process more elaborate.
The participant population should influence the choice
A method that works beautifully for one population can exclude another.
Electronic consent may be convenient for participants comfortable with digital systems but problematic for people with limited internet access, low digital literacy, inaccessible devices, or disabilities that the platform does not accommodate.
Written documents can create similar barriers for participants with limited literacy or visual impairments. Verbal communication may improve access for some people while creating difficulties for others.
The method should therefore be evaluated against the needs of the population actually being recruited, not the research team's preferred workflow.
Risk and complexity matter more than convenience
A low-risk online questionnaire and a complex clinical investigation should not automatically use identical consent procedures merely because both can technically be conducted online.
As the consequences and complexity of the decision increase, researchers may need stronger mechanisms for interaction, comprehension, identity verification, documentation, or ongoing consent.
The method should be proportionate to the research while still satisfying all applicable requirements.
The Declaration of Helsinki provides a useful medical-research comparison
The 2024 Declaration of Helsinki states that, after ensuring understanding, freely given informed consent in medical research should be formally documented on paper or electronically. When consent cannot be expressed on paper or electronically, non-written consent must be formally witnessed and documented.
This illustrates why researchers should resist simplistic rules such as "verbal consent never counts" or "electronic consent is equivalent everywhere." The appropriate method is defined by the ethical and regulatory framework governing the particular research.
04 · A Practical Example
One study, three possible consent approaches
Hypothetical Example
A study interviewing teachers about workplace experiences
A research team plans 45-minute interviews with teachers from several regions. Interviews can be conducted in person or remotely, and the study involves no intervention. The researchers are deciding how consent should be obtained.
Written approach
Participants attending an in-person interview receive an approved paper consent form, discuss questions with the researcher, and sign the form before the interview. They retain a copy.
Verbal approach
If the governing framework and ethics approval permit consent without signed documentation, remote participants could receive study information beforehand and discuss it by telephone or video call. The researcher obtains verbal agreement and records it using the approved procedure.
Electronic approach
Participants receive an approved electronic consent interface before the remote interview. They review the information, can contact the researcher with questions, and provide an electronic signature or another authorized indication of agreement.
Decision
The research team does not choose solely according to which method requires the fewest administrative steps. It considers participant access, confidentiality, documentation requirements, study risk, remote recruitment, institutional systems, and ethics approval.
Interpretation
More than one approach may be ethically workable. What matters is whether the selected process appropriately informs participants, supports a voluntary decision, and satisfies the requirements governing the study.
07 · A Quick Checklist
Before choosing written, verbal, or electronic consent
Before finalizing the consent method, check:
What consent and documentation requirements apply to this specific study?
Does the method allow participants to receive all information needed for an informed decision?
Can participants ask questions or obtain clarification when they need it?
Is the method accessible and practical for the population being recruited?
Does the process provide sufficient opportunity to consider participation without inappropriate pressure?
If a signature is required, does the chosen paper or electronic method satisfy the applicable signature requirements?
If no signature will be collected, has any required waiver of documentation been properly authorized?
Does the protocol specify how consent and any required interactions, witnesses, signatures, or records will be documented?
For electronic systems, have privacy, security, accessibility, identity verification, version control, and record retention been considered where relevant?
