How diary studies can help your product succeed

Ever wondered what users really think about your product over time? Diary studies offer a deep dive into user experiences, uncovering insights that traditional research methods might miss. In this article, we’ll show you how diary studies can help your product, share real-life case studies, and give practical tips to run one, even on a tight budget.

What is a diary study?

In user experience, a diary study is a valuable research method where participants record their experiences, thoughts, and interactions with a product over a set period. Unlike one-off usability tests or interviews, diary studies capture real-life usage patterns, emotions, and decision-making processes as they happen. 

This research method not only offers a rich understanding of user behavior but also enables designers and researchers to gain deeper insights into the needs, preferences, and pain points of users.

Diary studies are especially beneficial when you need to:

• understand user behavior and experiences over a long period of time – see how users interact with your product over days, weeks, or months;
• gain insight into the context in which users engage with a product or service, as well as the emotional and psychological factors that influence their behavior;
• go beyond what interviews can capture, and collect data that users might not remember or can’t articulate in a traditional interview setting.

In the end, you should be able to identify pain points and areas of improvement, emotional responses, people’s decision-making process, and the impact of external factors on their experience. 

How can diary studies help your product?

Diary studies offer rich qualitative data that can inform, for example, product development, marketing strategies, and customer segmentation. Here are three real-life examples of how we used them at UX studio:

Aiding customer segmentation by exploring decision-making process in the automotive industry

We helped a client in the German automotive market with behavioral segmentation. The goal was to segment customers based on their behavior during their car search, going beyond typical demographic grouping. 

The team used diary study to understand the customers' needs and behavior throughout their search journey. Interviews were not suitable for answering these research questions because they are influenced by recency and salience bias.

👉 Key insight: The diary study allowed participants to provide detailed information about the context of their car search, their use of online applications, and triggers for contacting car dealerships. 

We also learned what distinguished successful searchers from unsuccessful ones, helping us customize the online experience for each target group.

Improving payment experiences for a streaming platform

Payment processes significantly impact customer acquisition and drop-off, but users rarely remember their payment frustrations when asked later. Also, it’s hard to test real-time, because of the potential sensitive information involved. For an international streaming platform, we conducted a diary study to understand the usage and impact of instant payment options (iDEAL, Pix, Blik, etc.) on the purchasing process, and how that experience could be optimized.

👉 Key insight: By using a diary study, we tracked how users engaged with different payment methods in real-time, where users struggled with certain payment flows, leading to unnecessary drop-offs. Our findings helped the company streamline its payment processes to offer the best possible experience and increase conversion.

Testing smart wearables for meditation

Testing a smart wearable is not something you can easily do in a lab or artificial interview setting. Especially if it’s about breathing and meditation where not only usability matters but understanding people’s attitudes and emotions is crucial as well. 

Our research experts at UX studio proposed a diary study to really understand the daily or weekly meditation routine and needs as well as the emotional aspect of the product.

👉 Key insight: This approach not only helped improve product features like voice feedback but also provided the marketing team with valuable insights to refine messaging and boost sales. Read the full case study here.

Making diary studies work on a budget

The biggest misconception is that diary studies must be long, complicated, and expensive processes. And when you need to approach stakeholders with a $15,000 budget request just for a tool, it's easy to see where this misconception comes from.

It’s important to note that most diary study tools tend to be quite expensive, and the free trial versions often don’t allow for a sufficient amount of data collection.

But what happens when you don’t have the budget to get a “proper” tool? Or if your organization’s procurement process for a tool takes forever, would you miss out on starting the study on time? Should you just give up on your study?

We strongly believe that you shall not. Here’s the good news: you don’t need fancy tools to run an effective diary study. Diary studies can be smarter.

We've successfully conducted diary studies using Google Docs and WhatsApp. For example, when conducting a study in Germany, we leveraged WhatsApp because it was a familiar platform for participants. At the beginning, we sent the main instructions via good old email – including PDFs and step-by-step instructions on how they can record themselves on their Android/iOS phone. 

When someone didn’t get the hang of it, we followed up in the first week to ensure everyone was comfortable with the process. It was a bit of extra work from our side, but it ensured that we could actually run the study.

Common pitfalls (and how to avoid them)

Even with proper planning, diary studies come with challenges. Here’s how to overcome them:

1. Getting stakeholder buy-in

The time and budget needs of a diary study can easily scare product managers and lead to some resistance. So don’t start by simply telling them your budget needs. Understand their needs and show them how this is the best possible way to answer their questions. Be prepared for some pushback: it’s risky to do something new or something that seems time-consuming. 

What’s really important when it comes to stakeholder buy-in is to make your case by focusing on the value:

• Show how diary studies can be more cost-effective than running multiple interviews.
• Highlight the richness of insights compared to other methods.
• Provide examples of how the study will directly impact product decisions.

💡 Example: In a four-week study, participants spent about 35-40 minutes per week completing tasks. The cost was comparable to just two traditional interviews (excluding recruitment costs of the post-study interviews), yet we collected significantly more data.

An additional tip: you don't always have to go with the absolute best approach, a simpler diary study still aligning with the project's goals can be equally valuable.

2. Recruiting the right participants

Since diary studies require longer commitment and don't allow immediate follow-ups like traditional interviews, you need participants who not only match your target sample but are willing to share detailed experiences openly.

Look for participants who are:

• comfortable expressing themselves without needing too much probing, in written format as well;
• genuinely motivated to be there rather than just collecting the incentive;
• particularly engaged with the topic or product and can provide a range of perspectives and experiences.

Also, long studies risk losing participants along the way. To handle potential dropouts, recruit 10-20% more participants than needed. Besides that, try to make sure that your enrolled people are committed to logging their experiences consistently and in a detailed manner. If they cannot commit to spending 40 minutes every week on their tasks, no hard feelings, but they should not participate in the study.

💡 Our approach: Besides over-recruiting, we usually conduct a 15-minute pre-study interview with everyone who meets the screener's criteria. For that we invite 20-50% more candidates to be able to select the most suitable and committed participants. This interview allows us to assess and also ensure participants: 

• Understand the task and time commitment.
• Can clearly express their thoughts.
• Are genuinely interested in the study.

Additionally, the extra 15 minutes of time was great for building rapport and reducing dropout rates. By carefully selecting participants, we’ve achieved an almost zero dropout rate in one of our studies.

3. Keeping participants engaged 

Regular contact with participants is crucial for ensuring high-quality data collection in diary studies. People may be worried about what happens if participants fail to complete tasks or don’t do them correctly. But there's good news: you can stay in touch with them throughout the study.

For example, in our online payments study, we treated the first day as a trial run. We sent out initial tasks to help participants get familiar with the platform, learn how to record their screens, and understand the different task types (e.g., video responses, long text, image uploads). If any issues arose, researchers followed up immediately to address them. This approach improved data quality from day two onward while giving participants valuable feedback.

Ongoing communication is just as important. We regularly checked in with participants. Addressing questions and concerns they may have, fosters collaboration and encourages active engagement.

During a four-week diary study, we reviewed the logs received each week and asked participants to elaborate on any tasks that were incomplete or unclear. Or just simply sent a short reaction -- an emoji or “thank you” to encourage them further. This helped ensure that the study results were of the highest quality possible, and also helped get the participants engaged until the end.

💡 Tip: Keep engagement high to ensure data quality and participation by:

• Checking in regularly—even small follow-ups make participants feel heard.
• Providing varied tasks—mix text responses, videos, and screenshots to keep things interesting.
• Using playful or creative exercises to break monotony.

For instance, in the car search study, we combined routine surveys with engaging tasks. One week, participants recorded a 10-minute video of their search process, narrating their experience. Another week, they shared listings they found interesting but didn’t pursue. This mix kept participants engaged while gathering valuable data.

4. Avoiding data overload

Diary studies generate a lot of data - sometimes including data that is not relevant to the study -, thus delaying the analysis can quickly become overwhelming.

We advise against leaving data analysis until after data collection ends. It’s not rare that you have 50 hours of data and if you only leave one week for analysis, this is a massive amount of information to analyze. Instead, tag data as it arrives—this saves time and makes it easier to handle later.

Also, it helps with ensuring better quality responses. For example, in the payment experience study, tagging the first week’s data revealed that some participants misunderstood a task. We adjusted instructions for the following weeks, ensuring better quality responses.

💡 Example: In our study about payment processes, there was a lot of noise in the data. To stay on track, we created a tagging system based on research interests. The team used these tags to categorize their data, whether it came in the form of videos or texts. This helped us identify the most important insights and cluster other findings.

Example analysis from the study on online payments

5. Creating a proper process 

One important aspect of effectively managing tasking in diary studies is establishing a clear and structured process.

This involves:

• Implementing a well-defined system to provide participants with clear instructions and expectations for their diary entries.
• Considering the frequency and timing of tasks. Striking a balance between gathering valuable insights and not overwhelming participants is crucial.
• Prompting and asking guiding questions. Highly specific questions related to the study objectives encourage participants to reflect on their experiences and provide more detailed insights.
• BUT be flexible—if something isn’t working, adjust!

In summary, effective task management in diary studies involves careful planning, clear instructions, appropriate task frequency, thoughtful prompts, and regular communication with participants. These strategies enhance the quality and depth of collected data, leading to more meaningful insights.

Summarizing the best practices for running a successful diary study

• Over-recruit — to account for inevitable dropouts.
• Make sure you pick the right participants and that they understand the study’s timeline and what they’ll need to do. 
• Keep participants engaged — with regular communication, as well as diverse and interactive tasks.
• Monitor responses regularly — to ensure data quality.
• Start tagging and interpreting data early — don’t procrastinate.
• Be prepared but flexible — adjust if something isn’t working.

Conclusion

Diary studies are an excellent way to gain deep insights into user behavior over time. They are especially useful for capturing hard-to-recall experiences, understanding emotional and psychological factors, and observing real-world interactions. While concerns about cost and complexity exist, with the right planning and tools, diary studies can be a cost-effective and efficient research method.

By carefully planning, selecting the right participants, and keeping engagement high, you can unlock valuable user insights—even with simple tools like Google Docs and WhatsApp. Following our tips outlined above will help ensure the success of your next diary study.

Want to learn more?

If you’re interested in leveraging diary studies for your product, get in touch with us! UX studio has helped over 250 companies worldwide uncover user insights that drive real impact. Let’s discuss how we can help you too.

Credits
This blog post was written by Mariann Fülöp and Lilla Schmidt, UX researcher
Edited by Barbara Bicskei, UX researcher and lead
Proofread by Johanna Székelyhidi, marketing manager