Jan 23, 2019


  • Use of diary studies as tools for human factors research and design applications increasing
  • Diary studies providing more efficient access to longitudinal data

“Dear diary, Today I…”

Some people might assume that diaries are only used to record the day-to-day trials and musings of teenagers. But – surprise! – diaries (specifically, diary studies) are actually a valuable method to add to your ethnographic research toolkit. Generally speaking, a diary study is a qualitative research method that involves participants self-reporting data over an extended time period. Participants can record data in physical pen and paper diaries, or using one of many digital platforms that offer added value and efficiency.

In the product and service design industries, diary studies have become a popular user research tool to supplement (or even replace) observations, interviews, and other in-person methods. Within the umbrella of diary methods, there are a variety of ways to tailor the format according to the type of insights you seek – ranging from specific product usage feedback to an in-depth ethnographic picture. Utilizing such studies also stands to benefit human factors engineering and usability research in the medical device and healthcare product sectors.

Below are three major benefits of diary studies you should be aware of when considering how to tackle your user research goals:

  • Diary studies offer economical access to longitudinal data. Interviews, focus groups, standalone observation sessions and usability tests can yield lots of qualitative data in a short amount of time, but is difficult to gain an accurate understanding of a user’s behaviors or product experience over time. In contrast, long-term observational studies provide the most accurate view into a user’s life and experiences, but the cost and logistical challenges associated with such extended observations is often a barrier to this approach. A well-designed diary study enables participants to share their experiences (with reasonable self-reported accuracy) over time without relying on the researcher’s continuous presence.
  • Diary studies elicit in-context responses. Besides longitudinal data, a diary study is an effective means to collect feedback about specific moments or events in a user’s life. Asking a user about their living environment while they are seated at an interview table is unlikely to yield as detailed and accurate a response as if they are sitting at home. Furthermore, many diary platforms support multi-media responses, which enables participants to send photos and videos that provide high fidelity, in-context snapshots of relevant events. For example, in a recent diary study, we prompted participants to take pictures of each meal they eat during the day and describe in the captions how (if at all) their medical condition influences what they eat.
  • More time = More thoughtful responses. Diary studies give participants the freedom to respond to questions at their own pace rather than within the time constraints of a structured interview. Diary prompts tend to yield accurate and thoughtful responses because they alleviate the pressure on participants to respond immediately. Instead, participants may revisit and elaborate on a previous question if their daily experiences bring to mind new ideas, which offers us richer insights.

Perhaps the benefits described above have you eager to start planning a diary study right away? If so, here’s an overview of the next steps:

  1. Identify your research questions
  2. Develop prompts to guide participants
  3. Select a diary platform (Check out Indeemo.com*)
  4. Determine the appropriate study duration and timing of prompts
  5. Pilot test the study flow with internal teammates
  6. Recruit participants and kickoff!

*There are dozens of tools out there but Indeemo has worked very well for us. It supports multimedia posts from a mobile device, offers a well-organized researcher dashboard, and facilitates continuous communication with participants.

Erin Davis, MS, CHFP is Managing Human Factors Specialist and Benjamin Basseches is User Researcher at Human Factors Research & Design at Emergo by UL.

Additional human factors research and design resources from Emergo by UL:

  • Human factors analysis for medical devices and technologies
  • User research support for healthcare products
  • Human factors design and prototype development


  • Erin Davis and Benjamin Basseches