A Diary Study is a powerful tool for game developers looking to understand player behavior over time. Unlike traditional playtests, which typically focus on first-time user experience (FTUE), Diary studies allow you to assess player engagement, retention, and feature reception over multiple sessions spanning days or weeks. Whether you're looking to identify churn points or validate a new feature before a public release, this guide will walk you through the essential steps to conduct an effective Diary study.

Define Your Objective and Hypotheses

Before starting any study, it's crucial to define your purpose. Are you seeing high player churn after a few days? Do you want to validate how players interact with a newly added game mechanic? Start by establishing a clear hypothesis. Collaborate with your team to think of potential reasons behind certain player behaviors and design the test to prove or disprove these theories. The key here is to generate multiple hypotheses so you can gather comprehensive insights. Remember, a successful study is not just about confirming what you already know but also discovering unexpected patterns that can be game-changing.

Map Out the Study Design

The planning stage involves creating a roadmap for your study. Map out the game elements and mechanics that players will interact with. Think about how these elements help test your hypotheses. This stage is also when you determine the type of players you want to involve. Defining your target player profile is key—whether they are casual, midcore, or hardcore players, as well as their age, gender, location, and even the types of games they prefer.

Designing a Key Performance Indicator (KPI) sheet is an essential part of mapping out your study. This KPI sheet should track metrics like completion rates, engagement time, and satisfaction scores that will help you validate or disprove your hypothesis. Documenting your expectations and target KPIs will provide a benchmark against which you can measure player behaviors.

Set a Realistic Calendar

Planning a Diary study is more about organization than speed. Start by setting a project deadline and work backward from there to plan out your study timeline. Typically, diary studies run for 5-7 days, though you should account for a few extra days to gather complete data. Use tools like a Gantt chart or a simple calendar to schedule key milestones, such as survey deliveries, video analysis sessions, and team meetings. Be mindful of the workload—analyzing video playthroughs can be time-consuming, so it's best to set daily goals for watching player videos and reviewing surveys to avoid overwhelming your team.

Target Your Players Effectively

Selecting the ideal players is a crucial component of every type of playtest. Are you looking for players who only game casually or only want input from hardcore players? It’s important to choose people who resemble your audience. Moreover, take into account what devices your target players will use. Setting these parameters will help to get the best information about your game early on. 

Set up the Study and Gather Data

After finalizing your design, it’s time to set up your study. This means organizing sessions of the gameplay and making sure that the subjects are clear on what to do in each stage of the study. Surveys are important here. Daily surveys track how a player's experience changes over time. What they say is another piece of evidence beyond the game. If you ask the same question in a similar manner at different periods, it would be easier to trend.

During the study, you will receive daily gameplay videos. Analyzing videos incrementally, instead of waiting until the end, can help you stay on top of emerging trends. Be ready for some players to leave only after a few sessions and not to complete the entire test.  Although the study is designed for all participants to complete the full schedule, some won’t—either due to bugs, lack of interest, or becoming busy with real life. Over-recruit a little and replace people, so plan for dropouts.

Analyze and Evaluate the Results

After the research, it’s time to look into the outcomes. Go back to the KPI sheet you had prepared earlier and see how each player performed against those metrics. You can break down the data to avoid getting overwhelmed. For example, set a number to watch gameplay videos and mark them against your KPIs every day.

Then once you have done that, meet as a team to discuss what you have learned. These meetings have multiple phases, starting with an internal meeting which is attended by the team which actually analyzed the study data followed by a highlight meeting where a larger development team meets. Sharing video clips of key player moments can help illustrate your findings and foster a better understanding of player experiences.

The three core questions to answer during this evaluation phase are:

1. What goals did you achieve, and what evidence supports these findings?

2. Which hypotheses did the players disprove, and why?

3. What areas need improvement, and what changes should be implemented in the next development sprint?

Iterate and Prepare for Future Tests

The final step is iteration. Use the insights gained from the Diary study to improve your game, whether that means tweaking certain features or fixing pain points that were uncovered. Don't forget to archive the study videos—they can be valuable references for future tests or even as a baseline for comparison when new changes are implemented.

Ask yourself: Should you run a follow-up study to further validate your findings? Often, a successful Diary study will reveal new avenues for testing, uncovering unexpected player behaviors that are worth exploring in-depth.

Dear Diary

Running a successful Diary study requires careful planning, precise targeting, continuous evaluation, and an iterative mindset. It’s a process that can reveal not only whether players enjoy your game, but also how they engage with it over time. By structuring your study around clearly defined hypotheses and consistently analyzing player feedback, you can transform player insights into actionable improvements that bring your game closer to its full potential.