Diary Study

A diary study is a qualitative UX research method where participants record their experiences, behaviors, and thoughts over an extended period. This longitudinal study approach helps researchers understand how users interact with products or services in their natural context over time, revealing patterns and insights that single-session research might miss.

Why Diary Studies Matter

Diary studies provide unique insights that are difficult to capture through other research methods:

• Longitudinal perspective: Unlike one-time usability tests or interviews, diary studies track user experiences over days, weeks, or even months, revealing how behaviors and attitudes evolve over time
• Contextual understanding: Participants record their experiences in real-world situations, providing authentic insights about how your product fits into their daily lives
• Reduced recall bias: By capturing feedback in the moment, diary studies minimize the memory distortion that occurs when participants try to recall past experiences
• Pattern identification: The repeated data collection helps researchers identify recurring issues, usage patterns, and changing user needs

When product teams need to understand how users interact with products in their natural environments, or how attitudes shift during extended use, diary studies deliver valuable insights that point-in-time research methods cannot.

How Diary Studies Work

Components of a Diary Study

1. Planning phase

   • Define clear research objectives and questions
   • Determine study duration (typically 1-4 weeks)
   • Select appropriate data collection tools
   • Create a participant screening plan

2. Recruitment and onboarding

   • Recruit 10-15 participants who match your user profiles
   • Provide clear instructions and expectations
   • Conduct an initial briefing session or interview

3. Data collection period

   • Participants document experiences at defined intervals or trigger points
   • Researchers may send prompts or check in periodically
   • Data collection can include text entries, photos, videos, or experience sampling

4. Analysis and reporting

   • Organize and code the collected data
   • Identify patterns, pain points, and opportunities
   • Create journey maps or experience timelines
   • Develop actionable recommendations

Collection Methods

Several approaches can be used for diary studies:

• Interval-contingent: Participants record entries at specific times (e.g., daily at 8pm)
• Signal-contingent: Participants receive prompts or notifications to complete entries
• Event-contingent: Participants record entries when specific events occur (e.g., whenever they use a particular feature)
• Experience sampling method (ESM): A specialized form where participants report on experiences multiple times per day, often in response to random prompts

Best Practices for Diary Studies

✅ Start with clear objectives - Define exactly what you want to learn before designing your study

✅ Keep participant burden reasonable - Balance depth of insights with participant effort; 5-10 minutes per entry is often ideal

✅ Provide structure with flexibility - Use templates or guided questions while allowing for unexpected observations

✅ Send regular reminders - Gentle prompts increase completion rates without annoying participants

✅ Conduct entry and exit interviews - Bookend the study with interviews to establish context and clarify findings

✅ Use multimedia - Encourage photos, screenshots, or voice recordings to capture rich contextual information

✅ Compensate fairly - Recognize participants' sustained effort with appropriate incentives based on study length and complexity

Common Mistakes to Avoid

❌ Making the study too long - Participant fatigue leads to incomplete data or dropouts; 2 weeks is often the sweet spot

❌ Asking too much per entry - Overwhelming participants with questions decreases completion quality and frequency

❌ Insufficient participant training - Failing to properly onboard participants results in inconsistent or poor-quality data

❌ Neglecting mid-study check-ins - Without occasional monitoring, you might miss opportunities to clarify or redirect

❌ Over-structuring responses - Overly rigid formats can miss unexpected insights that open-ended questions might capture

❌ Under-budgeting for incentives - Diary studies require substantial participant commitment and should be compensated accordingly

Connection to Card Sorting

While diary studies and card sorting serve different research purposes, they can complement each other effectively in a UX research plan:

• Use card sorting before a diary study to develop initial information architecture or product categorization that you can then test longitudinally through the diary study
• Conduct card sorting after a diary study to validate terminology and organization based on the natural language and mental models revealed in diary entries
• Combine methods by including periodic card sorting exercises within a longer diary study to track how user understanding evolves with product familiarity

For example, if diary study participants consistently report confusion about finding specific features, a follow-up card sorting exercise can help restructure your navigation based on users' natural categorization patterns.

Take Your Research Further

Diary studies provide powerful insights into user behaviors and experiences over time. When planning your next research initiative, consider whether longitudinal data would help answer your key questions about how users interact with your product in their daily lives. By combining diary studies with other methods like card sorting, you can develop a comprehensive understanding of both what users do and how they think about your product.