Data Collection

Mobile Diary Studies: The Complete Researcher's Guide

Jul 22, 2021
Data Collection

Dear Diary,

I have been struggling with an eating disorder for the past few years. I am afraid to eat and afraid I will gain weight. The fear is unjustified as I was never overweight. I have weighed the same since I was 12 years old, and I am currently nearing my 25th birthday. Yet, when I see my reflection, I see somebody who is much larger than reality.

I told my therapist that I thought I was fat. She said it was 'body dysmorphia'.
She explained this as a mental health condition where a person is apprehensive about their appearance and suggested I visit a nutritionist. She also told me that this condition was associated with other anxiety disorders and eating disorders. I did not understand what she was saying as I was in denial; I had a problem, to begin with. I wanted a solution without having to address my issues.

Upon visiting my nutritionist, he conducted an in-body scan and told me my body weight was dangerously low.

I disagreed with him.

I felt he was speaking about a different person than the person I saw in the mirror. I felt like the elephant in the room- both literally and figuratively. He then made the simple but revolutionary suggestion to keep a food diary to track what I was eating.

This was a clever way for my nutritionist and me to be on the same page. By recording all my meals, drinks, and snacks, I was able to see what I was eating versus what I was supposed to be eating. Keeping a meal diary was a powerful and non-invasive way for my nutritionist to walk in my shoes for a specific time and understand my eating (and thinking) habits.

No other methodology would have allowed my nutritionist to capture so much contextual and behavioural information on my eating patterns other than a daily detailed food diary.
However, by using a paper and pen, I often forgot (or intentionally did not enter my food entries) as I felt guilty reading what I had eaten or that I had eaten at all.

I also did not have the visual flexibility to express myself through using photos, videos, voice recordings, and screen recordings. The usage of multiple media sources would have allowed my nutritionist to observe my behaviour in real-time and gain a holistic view of my physical and emotional needs.

I confessed to my therapist my deliberate dishonesty in completing the physical food diary and why I had been reluctant to participate in the exercise. My therapist then suggested to my nutritionist and me to transition to a mobile diary study.

Whilst I used a physical diary (paper and pen), a mobile diary study app would have helped my nutritionist and me reach a common ground (and to be on the same page) sooner rather than later.

As a millennial, I wanted to feel like journaling was as easy as Tweeting or posting a picture on Instagram. But at the same time, I wanted to know that the information I  provided in a digital diary would be as safe and private as it would have been as my handwritten diary locked in my bedroom cabinet.

Further, a digital food diary study platform with push notifications would have served as a constant reminder to log in my food entries as I constantly check my phone. It would have also made the task of writing a food diary less momentous by transforming my journaling into micro-journaling by allowing me to enter one bite at a time rather than the whole day's worth of meals at once.

Mainly, the digital food diary could help collect the evidence that I was not the elephant in the room, but rather that the elephant in the room was my denied eating disorder.

The elephant in the room

What is a Mobile Diary Study?

A mobile diary study, similar to a physical diary, is a way to collect thoughts and feelings (qualitative information) about specific actions or daily life.

This is an excellent research method for understanding situational experiences, emotional feedback and fluctuations in participants' answers to questions.

This practical tool to collect information is not exclusive to health care professionals. A diary study platform can be equally powerful for professions ranging from academia to qualitative researchers to media, finance, and food.

Whereas a survey, an interview, or a quick doctor's interview could help a researcher know 'what' happened, a qualitative research tool such as a mobile diary study allows a researcher to know 'why' something happened and 'how something happened'.

The power mobile diary studies have in capturing data lies in collecting data longitudinally (over time). By prompting participants to respond by multiple entries, researchers can capture repetitive behaviours. Once data patterns start to arise, the data results can be trusted.

Compared to a detailed interview or a focus group discussion where a researcher gathers information from a subject or several subjects, a mobile diary study offers a richer and more organic insight by providing real-time responses rather than relying on the limitations of the limitations relaying recall.

Such an agile tool and research methodology yields accurate and contextual information that can be translated into tailor-made solutions for users. These solutions can range from medical treatment plans, workout routines, food options, or customized products that a user would likely purchase by understanding what matters to them.

Possible Uses of a Mobile Diary Study

The qualitative information captured by a digital diary study can be utilized in medical research such as mental health, pharmaceutical follow up, and nutrition tracking. It can also be used for broader purposes, such as helping to define and understand user feature requirements and marketing research to analyze consumption patterns.

1. Medical Research

The uses of a mobile diary study for medical research are broad. Overall, researchers can use the information provided by their subjects during clinical and behavioural trials or disease treatment and management.  

The benefits of this digitalized and real-time experience sampling method in medical research are:

  • Providing clinical and research staff with real-time patient information.
  • Ensuring patients enrolled in a clinical trial are compliant to assessment filling regimens.
  • Sending patients timely and scheduled alerts (push notifications) for completing their assessments.
  • Catering to patient diversity through leveraging the ability of mobile technology to enable the collection of data in multiple languages.
  • Allowing patient empowerment through immersing them in the data collection process.
  • Utilizing data visualizations to show treatment progression or regression.
  • Putting patients in charge of their health.

Three medical fields in which a daily diary app could prove beneficial are Mental Health, Pharmaceutical follow-up, and Nutrition.

A) Mental health

Among the most common health conditions affecting adults are mental health disorders. In middle income and high-income countries, over 50% of the general population is estimated to suffer from at least one mental health disorder in their lifespan. In parallel, smartphone ownership has been increasing in the developed world, with as much as 84% of any developed country citizens having access to this technology.

Daily diary study apps can be a powerful and accessible tool to evaluate the patterns and progress of mental health patients effectively and efficiently. Such a non-invasive technology is an easy and accessible way for a clinician to walk in a patients' shoes for a defined period to assess participants and measure intervention effects in clinical research and routine care.

Further, a daily diary study app for mental health patients can only venture beyond the traditional collection of written information. Smartphone technology has facilitated collecting data in eclectic ways such as videos, photos, and voice recordings using the click of a button. Speech patterns can provide critical insights into a patient's health status. Similarly, video analysis can provide valuable health insights. This particularly stands true for a mental disorder such as depression associated with a flattening of positive emotional responses.

A daily diary study app through prompting a user to interact and describe how they are feeling emotionally and physically can have multiple benefits. Initially, these user inputs can help enable self-assessment by comparing data and video entries over time. Also, the analysis of facial expression, voice acoustics, and voice sentiments collected using an app in consolidation with other contextual data can help researchers and clinicians to extract possible health outcome measures for mental health patients.

Overall, a mobile diary study for a mental health patient is a cost-efficient and effective methodology through understanding their context and factors that influence how they act, think, and feel in a particular moment. This empathetic tool of collecting qualitative information adds depth to clinical data and metrics, thereby empowering patients and improving compliance with treatment plans.

While such software would need advanced cloud analytics and a crucial feature of data protection, it would have the benefits of collecting versatile data and providing a tailored treatment plan.

B) Clinical trials and pharmaceutical follow-up

Daily diary study apps can be powerful tools in providing valuable insights into a treatment plan.

They can further help healthcare professionals and clinicians make critical decisions on a diagnosis or treatment regimen. With the multiple distractions of life, a daily diary study app can help simultaneously remind patients to adhere to their treatment protocol by setting alerts and entering data on how they feel prompted by push notifications.

For patients, daily diary study apps can be empowering and can lead to enhancing medical self-management. This allows patients to visualize and track how their symptoms change over time, identify patterns that may emerge to treatment protocols, and notify their physicians of the subtle nuances between different medications. Thus, the benefit of the application would be allowing patients to be in the driving seat of their treatment protocol.  

C) Nutrition

A physical food diary is limited in measuring with accuracy an individual's food consumption. Daily diary study app usage offers a novel dietary assessment method by prompting a subject to capture real-time food intake and analyze other contextual patterns regarding eating habits.

This application would serve as a 24/7 on-call dietician to efficiently track food intake throughout a period regardless of your nutritional goal. Such an interactive tool would also have the unique advantage of collecting authentic everyday food patterns through videos, photos, screen recordings or text.

For eating disorders (both overeating and undereating), a mobile food diary study can have the unique advantage of interacting in real-time with participants. This would be possible through an app questioning and probing dietary entries using comments and push notifications. The rich interaction of collecting data through multiple modalities can help a researcher or a clinician understand user nutritional behaviours, eating habits, and emotional experiences whilst maximizing respondent engagement.

2. User Experience (UX) Research

To enable researchers to understand how users and customers experience products and services, longitudinally (over some time) mobile diary studies can be used. Unlike product surveys that collect user perspectives and experiences cross-sectionally (in one point of time), diary studies provide more prosperous and more detailed data.

Diary studies can contextually understand user behaviour over time by providing organic behavioural insights and valuable information on customers' real-time and real-life behaviours and experiences. Although a diary study can't provide rich or detailed data on user experience as an actual field study, the information provided can be a close approximation.


If appropriately used in the 21st century, data could save us from lots of failed interventions and enable us to provide evidence-based solutions towards tackling malaria globally. This is also part of what makes the ALMA scorecard generated by the African Leaders Malaria Alliance an essential tool for tracking malaria intervention globally.

If we are able to know the financial resources deployed to fight malaria in an endemic country and equate it to the coverage and impact, it would be easier to strengthen accountability for malaria control and also track progress in malaria elimination across the continent of Africa and beyond.

Odinaka Kingsley Obeta

West African Lead, ALMA Youth Advisory Council/Zero Malaria Champion

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3. Marketing Research – Consumption Diaries

Marketing research can benefit from diary studies by getting customers repeatedly to enter what they buy or consume, thereby enabling researchers to prove actual daily behaviours. Consumption diaries are helpful to unlock patterns such as what time of day users engage with a product.

Other long-term behaviours such as what motivates people to buy certain items and how buyers feel upon purchasing something can also be understood through diary studies. Understanding what users are thinking while buying a product or a service can be estimated through information logged during a diary study.

The extended period of diary studies and the immersive information collected is a way of ethnographic research. This is a qualitative method where researchers interact with participants in their real-life environment. Thus, enabling marketeers to design far better solutions for their customers' needs.

Challenges of Collecting Daily Data from Participants

While diary studies provide a contextual understanding of user behaviours and experiences over time, this insightful information comes with challenges.

The main challenges of collecting daily data from participants are:

  • Alert fatigue is when a user receives too many alerts or notifications from the data diary leading to desensitization. When a system sends too many alarms to gather detailed data, it may be counterintuitive. A user may experience alert fatigue and start ignoring all notifications-thus providing no data at all.
  • Surveys that are too long, leading to a high participant dropout rate (high attrition).
  • Participants that don't feel comfortable sharing their data on an unknown platform.
  • Lack of compliance in participation due to little or no incentives (particularly in marketing diaries).

Solutions to Challenges of Collecting Daily Diary Data from Participants

Mobile diary study apps are powerful tools to longitudinally and remotely collect research data on human needs, habits, experiences and emotions.

Diary studies are most helpful in understanding long-term behaviours such as attitudes and motivations, changes in behaviours and perceptions, and understanding habits. The best way to avoid the challenges of using this tool is to employ the device correctly. Before you use a diary study app, make sure that you use the tool for the proper purpose.

Some ways to avoid the above challenges of daily diary data are as follows:

Conduct a pilot study

Before launching a full-fledged diary study on a specific research or subject, it is best to test the study design and related materials through a pilot. The purpose of the pilot will not be to yield data for analysis but rather to get feedback about the research materials and the diary study experiences and to adjust accordingly.

Plan an appropriate study time

A diary study can range from a few days to a few weeks. While data collected over a more extended period may better enable researchers to unlock user behaviour patterns and understand habits, this does not justify having an excessively long diary study.

If a study is too long, participants will experience fatigue, and the attrition rates will be high, resulting in less accurate data. On the other hand, a diary study that is too short will defeat the purpose of the study as information will not generate the necessary depth and detail. A pilot can help determine the appropriate study time depending on the research purpose.

Incentivize users

Diary studies require more involvement from users over some time. Before a diary study, explain to users what is expected from them, what is involved in the data collection process, and how the data collected will be used.
For medical research, many users will be self-incentivized as it is easy to connect between data provided and improved treatment plans and treatment outcomes. For marketing purposes, users may need to be financially incentivized to ensure commitment to the entire study.

Take data privacy seriously

Do your research before using a diary study or journaling app to ensure that there are provisions for data protection. This is particularly of importance for health data diaries. An easy thing to look for is whether an app has passcode locking to generate access to information. Another thing to look for is how the data is stored. Ideally, data stored should be locally encrypted to avoid unlawful access to information if a mobile is lost.


With the rampant use of smartphones (mainly in developed countries), a powerful data collection tool of mobile data diaries is available at the tip of your fingers. This is the equivalent of having an incognito diary that could be used anywhere and anytime. Additionally, through the usage of data intelligence features such as push notifications, a data diary will ensure entries are not missed.

With a data diary, researchers can make better decisions to improve the experiences of their clients through understanding their habits better. For medical professionals and patients, data diaries can help ultimately develop the ideal patient-specific treatment.  A data diary can help users understand and avoid specific triggers through organic information offered in moments of truth.

Finally, a daily diary will be a loyal and trustworthy companion. This tool will keep your information secure, provide you with visual representations of your thoughts. Over and above, a data diary can help you track your symptoms, habits, and experiences to unlock patterns and possibly improve your physical and mental health.

Dear Digital Diary,

I realized that there is an unquestionable comfort in being misunderstood. For to be understood, one must peel off all the emotional layers and be exposed.

This requires both vulnerability and strength. I guess by using a physical diary (a paper and a pen), I never felt like what I was saying was analyzed or judged. But I also never thought I was understood.

Paper does not talk back.Using a daily digital diary has required emotional strength. It has required the need to trust and the need to provide information to be helped and understood.

Using a daily diary has needed less time and effort than a physical diary as I am prompted to interact through mobile notifications. I also no longer relay information from memory, but rather the medical or personal insights I enter are real-time behaviours and experiences.

The interaction is more organic. I also must confess this technology has allowed me to see patterns in my behaviour that I would have otherwise never noticed. I trust that the data I enter is safe as it is password protected. I also trust that I am safe because my doctor and nutritionist can view my records in real-time.

Also, with the data entered being more objective and diverse through pictures and voice recordings, my treatment plan has been better suited to my needs.

No more elephants in this room

Rawan Taha's profile picture

Rawan Taha

Rawan is a PRINCE2-certified project manager and a Public Health professional with 3 years of experience managing development projects. She recently served as a Programme Analyst with UNDP in Zambia providing project support across topics such as Inclusive Cities, Climate Action, and Economic Growth. She was part of the inaugural cohort of a 16-month fellowship titled the African Young Women Leaders. Rawan aspires to rise as a development expert with the United Nations.

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