How to write an informed consent form 

Participants must have a real choice whether to participate or not. Although coercion and intimidation are obvious violations, be aware that disproportionate compensation and power imbalances should also be avoided. For example, students must not feel compelled to consent to a research study for the sake of their studies, nor should any participant consent because the compensation is vital to their survival or quality of life.
 

Research projects can often involve multiple types of processing. In such cases, the participants should be free to choose which purpose they accept, rather than having to consent to a bundle. For example, if a research project involves behavioral tests, interviews and surveys; the participant should be able to consent to each process separately if they are not all necessary for participation in your project.

The concept of specificity also extends to the way in which the collected data is going to be used. Thus, the data should only be used for the purpose for which it was specified in the information sheet. Since this would compromise your ability to share data, the re-use of data for research purposes is allowed under the GDPR. To be able to share your data for reuse purposes for research, you must ensure that participants have been informed about the intent to share and the data should be adequately safeguarded with clear security and privacy measures (i.e., secure storage, access restriction, pseudonymization, aggregation and minimization). 

Providing information is essential to a valid consent. How the information is provided however need not always be through a written information sheet. This means valid information may be presented in other ways, such as oral statements, or audio/video messages. 

The information provided must be clear and understandable and “the action of giving consent” has to be unquestionable and explicit. To demonstrate a clear affirmative action, the participant must take a deliberate action. For this reason, pre-ticked opt-out boxes are invalid, since they require no action from the participant. Ambiguity can also be avoided by providing participants with the option to tick a “NO” or a “YES” box, instead of only a “YES” box. The deliberate action of consent can be both a written (e.g., ticking a box, writing an email) or a recorded oral statement.  

In research, signing a consent form is rarely needed, as it often leads to the collection of unnecessary personal data, and a consent form is not a binding document anyways (it can be withdrawn at any point). Therefore, a signature only makes sense if the identity of the individuals is meant to be used in the process (e.g., in clinical trials), since that does not lead to additional data collection. If your research does not require the collection of names, or is using pseudonyms, using a signature leads to the collection of unnecessary personal data and is therefore not necessary. A check box (and possibly a statement/signature of the person/researcher who collected the consent) is often sufficient.