Using Plain Language in Participant Materials

Standards to Apply| Appropriate Reading LevelTips for Clear and Direct WritingVisual Ease| Resources

Plain language is “clear, easy to understand with no ambiguity or unnecessarily difficult words” (Collins Dictionary, 2022). Research materials written for participants (e.g., recruitment advertisements, information letters, study instructions) should be written at an appropriate reading level for the participant group. Participants must be able to understand what will be happening in the research study to provide informed consent.

Advantages of using plain language:

  • Producing materials that are free from jargon and that are easy to understand shows respect to study participants and may lead to greater interest.
  • Promotes inclusivity as a greater number of potential participants will be able to respond to and understand what the study is about. 
  • People appreciate reading materials that are organized so that they can quickly grasp what the study is about and what they are asked to do. 
  • Participants are more likely to follow the study protocol resulting in better data and fewer risks.

Standards to Apply When Writing Materials

  • Materials should be written in a manner that is both understandable and considerate of the target population(s).
  • It is a researcher’s responsibility to create materials and use language that participants can understand.
  • Ask a partner organization or the study site for a copy of their readability policies and practices. For instance, if you are working with a school board, ask if they have guidance on readability that should be followed. 
  • Translate materials to the primary language of the study population(s). Ensure the translated materials are written at the appropriate reading level.  

Readability Considerations

Appropriate Reading Level

  • Write to the literacy level of the intended population. It is recommended that for most studies researchers keep a maximum reading level of grade 8.
  • Tailor the materials to different ages or literacy levels if the population includes a variety of different ages or literacy levels.
  • Use readability tools and calculators (e.g., Microsoft Office) to check reading level.

Tips for Clear and Direct Writing 

  • Simplify, so long as it does not affect the information shared.
  • Avoid using jargon and technical language in your study title and throughout your study materials.
  • Write short, direct sentences. Divide sentences into two when necessary.
  • Present material logically and in a way that is easy to understand.
  • Keep paragraphs short and limited to one idea.
  • Use active voice instead of passive. Write the way you would naturally speak. See guidance from the Writing and Communication Centre for using the active voice.

Table 1: Examples of Passive Voice and Active Voice

Passive Voice

Active Voice

The survey will be taken by all participants.

All participants will take the survey.

Interviews will be conducted by a member of the research team at a mutually agreed upon location.

Researchers will conduct the interview at a mutually agreed upon location.

The effect [insert text] on [insert text] was studied by researchers.

Researchers studied the effect of [insert text] on [insert text].

Your blood pressure will be measured by trained researchers. 

Trained researchers will take your blood pressure.

  • Keep words to three syllables or fewer. Words with one or two syllables are ideal. 
  • Spell out acronyms when first used.
  • Write concisely. The University of Waterloo’s Writing and Communication has several tips and resources.
  • If you are providing a link to an external policy (e.g., a privacy policy) provide a lay summary of key points.
  • Use common terms and everyday language whenever possible. Use words familiar to the non-technical or non-scientific reader.
  • Use a thesaurus or dictionary to find substitutes for complex words and concepts. Participants should not need to use a dictionary to become familiar with scientific terms. 

Table 2: Examples of Academic Terms and Simplified Terms

Academic Term

Simplified Term




find out


take part or be in






check, explore





Visual Ease

Make your materials visually appealing and easy to navigate.

  • Use adequate spacing and white space to make the content inviting to read. Avoid crowding words and letters. 
  • Use headings/subtitles. These reduce content density and serve as "road signs." 
  • Use lists rather than paragraphs when possible. 
  • Use page numbers on materials. 
  • Use at least 12-point font and consider a larger font based on your audience (e.g., individuals with low vision). 
  • Avoid excessive use of bold type, which can lead to participants overlooking important information not in bold type. 
  • Use photos, graphics, or tables if these will help clarify procedures. 

Support Comprehension and Further Clarifications

Provide opportunities for participants to ask questions and clarify what they have read or been told. 


A Beginner's Guide to Writing Concisely. Writing and Communication Centre, University of Waterloo. Accessed on October 27, 2022 from:

Accessibility Checklist for MS Word. Centre for Teaching Excellence, University of Waterloo. Accessed on October 27, 2022 from:

Active and Passive Voice. Writing and Communication Centre, University of Waterloo. Accessed on October 27, 2022 from:

Writing Concisely. Writing and Communication Centre, University of Waterloo. Accessed on October 27, 2022 from:

This guidance was adapted with permission from the WestEd document "Regulated Research: Minimum Standards and Requirements - Readability & Comprehension of Informational Materials for Participants"


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