For companies For testers flags img flags img

Diary studies

See how you can use diary studies as a method to develop your products and services

What is a diary study?

Diary study is a qualitative method where you learn more about your users’ behaviors, thoughts, feelings, and attitudes. In a diary study, qualitative data is collected to gain a better understanding of the test participants’ experiences regarding a product or service over a specific period of time.

It is the test subjects themselves who keep a diary during the testing period. The period can be a few days, a few weeks, or a few months. During the diary study period, the test participants are therefore required to keep a diary, digitally or with pen and paper, specifically about the product or service that is being evaluated. In a diary study, the test subjects can also document their experiences using photos and videos.

With an increased understanding of the users’ needs, habits, and patterns, product or service development becomes both easier and more efficient.

Why do you do a diary study?

If you are offering your customers a complex product or service that will be used for a long time, a diary study can be an excellent testing method. It can be difficult for test subjects to remember all the details in a single instance, such as during an in-depth interview. If you were to use a survey instead, you could miss out on important perspectives. A survey usually does not allow test subjects to provide deeper and more elaborative answers to the questions.

The diary method, on the other hand, provides knowledge about how the product or service is used in real time and can provide a long-term contextual understanding of the test participants’ user experience. The study can reveal something about the test participants’ habits: when the product or service is used and how the attitude and motivation are experienced. The study can also show if the test participants’ behavior changes over time, simply describe the entire customer experience or customer journey.

Common subject areas for diary studies

A diary study can increase understanding within a broad range of subjects. In many cases, the study is intended to provide answers on how a product or service is used and how behavior changes over time. It can be about the participants’ willingness to share information through social media or how a purchase on a website goes from inspiration to an actual conclusion. It can also be a more general activity to be studied, such as what the participants’ grocery shopping looks like, or a more specific activity, such as how the participants use a certain app for their grocery shopping.

How does a diary study work?

In a diary study, the test subjects are to record their experiences of the product or service over a longer period of time. It can be anywhere from a few days to a few weeks or months. The diary can be kept digitally or with the help of paper and pen. Keep in mind that it may take time to interpret the participants’ handwriting and transfer the information digitally when choosing a paper diary. If you choose an electronic diary, there is the possibility for participants to add photos and videos in a smoother way.

The diary that the test subjects are supposed to fill in can be open and free. This means that the participants themselves get to decide when, where, and how they should keep their diary. It can provide information that you may not even have thought to ask about, but it can also provide too little information about things you actually want to know.

You can also choose a structured form of diary with more detailed instructions, questions, and specific time indications for when notes should be made. In doing so, you often receive the information you have requested, but you may lose the knowledge that participants write more spontaneously. In many cases, a mixture of open and structured diary is used.

At the end of the diary study, the diaries are collected to be evaluated and analyzed. Sometimes, the study is also concluded with an interview with the participants where they are given an opportunity to explain and further develop their notes in the diary.

Diary studies in different phases of product or service development

A diary study can be conducted early, in the middle, or at the end of a product or service development. It simply depends on the purpose of the study. Simply put, the different stages can be described like this:

  • early – to investigate the users’ needs and gain increased understanding of which products and services are in demand
  • middle – to analyze and identify problems in early prototypes and solutions
  • the end – to check the functionality and adjust details.

When should one choose a diary study as a method?

Diary studies can help you understand how users interact with your product or service in real-life situations over a specific period of time. The study can help you see the users’:

  • habits
  • attitudes, thoughts, and feelings
  • changes in behavior.

How do you find participants for diary studies?

A diary study consists of five steps.






All parts are equally important for the study to provide a useful result. We at FeedbackFrog can help you with the recruitment of your test participants. We find and book participants that fit your desired target group. We can recruit test participants based on interests, age, gender, computer skills, and language, among other things. We take care of all administration and contact with the test participants.

Find out what it would cost to order participants for user testing

What are the advantages and disadvantages of diary studies?

Advantages of diary studies

  • can map the test subjects’ behavior and relationship to the product or service over a longer period
  • can provide qualitative data on how the product or service is used and perceived in the right context
  • can provide more reliable and honest information compared to methods where the questions are asked and answered afterwards
  • can provide deeper and more detailed information
  • can reduce the risk of the test participants being influenced by the interviewer, observer, or moderator
  • can be supplemented with photos and videos for a better understanding.

Disadvantages of diary studies

  • requires more time to prepare and execute
  • depends on the test subjects’ engagement
  • provides a large amount of collected material that requires analysis.



    Contact us for advice

    Frequently Asked Questions & Answers

    Add a couple of Frequently Asked Questions & Answers