Attention drawing writing


This practical guideline helps you to improve your writing for information letters to recruit participants for your research.

How to

A proper, attractive and clearly presented information package may help convince individuals to participate in your study. For all research under the Medical Research Act (WMO), approval of the brochure and information letter by the Medical Ethics Research Committee (Medisch Ethische Toetsingscommissie, METC) is required. Once approved, the brochure and letter cannot be altered without consent from the METC. In case of research not under the remit of this Act (niet-WMO plichtig onderzoek), the METC still strongly advises to inform them about any changes. The CCMO offers a guideline for the subject information file. Some recommendations for writing information letters can be found below:

  • The typical behaviour of someone receiving an information package;
  • The envelope;
  • The response options;
  • The letter (including example);
  • The brochure;
Typical behaviour on receiving an information package
  1. The recipient looks at the envelope and sees who has sent it. Based on this they will decide: Shall I open the envelope and have a look? Or shall I just throw it away unread?
  2. After taking a quick glance at the letter and perhaps the brochure included, their attention will start to turn to the response options, such as a reply card. Clearly, that is where they expect to find a brief summary of what is involved. They want to get an idea of what the consequences are if they read any further.
  3. Is the response option clear? Will the topic scare them off, or will it have the opposite effect and interest them? The recipient will then have a look at the letter and read it in more detail. Will they discover an extensive description of the topic that will capture their imagination? If so, they will read through the sections fairly intensively.
  4. Has a brochure been included? The recipient will normally find a comprehensive description of the topic here, along with illustrations and sufficient or more extensive background information.
  5. Finally, the reader will return to the response options. They will carefully read through the topic again and will re-examine what they need to fill out. They will complete it in full and put it aside for posting.

Information packages such as these (referred to as direct mail in the business world) have a strong focus on obtaining a response from the reader. The package received by the potential research participant should be viewed as the first example of the professionalism with which you approach the study. And this should therefore also be reflected in the visual presentation of the material!

The envelope


  • Make clear that it is personally addressed to the recipient, preferably by name. Make sure the labelling is tidy (not skewed, which gives the impression of haste and a lack of care). A good quality envelope, clear sender’s details and a carefully completed, personal address are all required.
  • Use the Amsterdam UMC house style: This is an important recognition point for the recipients of the letter. Furthermore, recipients, in general, are more likely to open letters from organisations they are linked to, from whom they have requested information or – as is the case for the Amsterdam UMC – organisations with a good reputation
The response options

The response option is there to lead the recipient to the real contents of the mailing. The options usually consist of:

  1. Requesting more information
  2. Registering (agreeing to participate in the study)
  3. Declining participation (optionally including the reason for declining)

The most common form of response option is the response form or reply card, preferably provided with a pre-printed response envelope.

Elements of a response form;

  • Subject: Subject of the mailing. Can generate interest.
  • Response options: Indicate the way in which potential research participants can reply.
  • Researcher’s obligations: Indicate what you will do in response to receiving the form.
  • Expectations: Describe what the potential research participant can expect and what they are agreeing to undertake by returning the card.
  • Details of potential researcher participant: Enable the researcher to respond to the reader.
  • Researcher’s details: Describe exactly who the researcher is.
  • Address: Provide address details where the potential research participant sends the letter.


  • Ensure that the potential research participant has only to complete a minimum number of fields themselves (for instance, create tick boxes the recipient can select). This guides completion in columns, encouraging full completion.
  • Avoid open questions.
  • Avoid the construction “Delete what is not applicable”. Instead, create a question that can be answered “yes” or “no” with tick boxes. This organises the form and makes it easier for the reader.
  • Tick boxes also facilitate the processing of the response letter.
  • Indicate a time when you will contact the potential research participant again (i.e. we will contact you by telephone within two weeks to make an appointment).
  • Make sure there is enough space to fill in details.
  • Make it as easy as possible for the potential research participant to reply. Freepost (Antwoordnummer) is best, but enclosing an envelope (with postage) or stamp increases the likelihood of a response.
The letter

It is strongly advisable and for the Medical Research involving Human Subjects Act (WMO-plichtig onderzoek) even obligational to use the formats that are provided by CCMO and METc. See here for the format of the CCMO. A version for adults (>16 jaar) and a version for minors is available. Both are in Dutch. For niet-WMO plichtig onderzoek, the METc provides a format for prospective research and retrospective research.  

Creating a recruitment letter using the AIDA formula (Attention, Interest, Desire, Action)

  • Introduction: Grab attention

The start of the letter has to grab the attention, just like the subject line and the PS option at the bottom of a letter.

  • Middle section: Creating interest and attention

What is the need for the research? How many people are involved in the subject you are studying? For instance, how many people in the reader’s neighbourhood could have that specific disorder?

  • Show potential research participants the importance and utility of the research to encourage them to participate.
  • Ending: Impulse to spur into action
    • Tell the reader exactly what they need to do
    • Tell the reader how they should do this
    • Make participation easy for the reader, or make it sound easy


  • See CCMO guidelines and formats
  • Refer to the response option and any potential other documents/brochures in the letter.
  • Use personal pronouns (address the reader as “you”, rather than using “one”, for instance).
  • Use passive phrases as little as possible, and use active language (for instance, don’t say “The urine sample can be dropped off”, but rather say “You should drop off the urine sample”).
  • Link in as much as possible to the potential research participant’s daily life. There are a number of emotional needs that may be applicable to the recipient of the letter regarding participation in a scientific study:
    • Not having to go to any trouble or make any effort;
    • Becoming healthier;
    • Satisfying curiosity;
    • Protecting the family.