Dr. Egon Dejonckheere
Egon does research in Emotion, Clinical Psychology and Abnormal Psychology. His most recent publication is 'The Bipolarity of Affect and Depressive Symptoms', featured in Journal of Personality and Social Psychology: Personality Processes and Individual Differences.
What is ambulatory assessment
Ambulatory assessment refers to a family of research methods designed to measure people’s experiences, emotions, behaviors, symptoms, and cognitive processes as they unfold in everyday life. Instead of relying solely on retrospective questionnaires or observations in laboratory settings, ambulatory assessment or daily life research collects data in real time and in natural environments, often using smartphones, wearable devices, or other digital technologies.
Specifically, the term serves as an umbrella concept that encompasses a range of data collection approaches used to study individuals in their daily contexts. These approaches include the Experience Sampling Method (ESM), Ecological Momentary Assessment (EMA), and daily diary studies, which typically involve repeated self-report surveys delivered throughout the day or once per day. In many modern studies, these self-reports are combined with mobile sensing (e.g., smartphone or wearable sensors that capture contextual or physiological signals) and mobile cognitive tasks that allow researchers to assess processes such as attention or memory under real-world conditions.
Across these different approaches, the core idea of ambulatory assessment is that behavioral, psychological, and physiological processes are dynamic and context-dependent. Emotions, thoughts, behaviors, symptoms, and cognitive functioning fluctuate across time and situations. To study these processes adequately, researchers therefore rely on repeated measurements collected during daily life rather than single, static assessments. These data streams are called intensive longitudinal data or time series data.
Specifically, the term serves as an umbrella concept that encompasses a range of data collection approaches used to study individuals in their daily contexts. These approaches include the Experience Sampling Method (ESM), Ecological Momentary Assessment (EMA), and daily diary studies, which typically involve repeated self-report surveys delivered throughout the day or once per day. In many modern studies, these self-reports are combined with mobile sensing (e.g., smartphone or wearable sensors that capture contextual or physiological signals) and mobile cognitive tasks that allow researchers to assess processes such as attention or memory under real-world conditions.
Across these different approaches, the core idea of ambulatory assessment is that behavioral, psychological, and physiological processes are dynamic and context-dependent. Emotions, thoughts, behaviors, symptoms, and cognitive functioning fluctuate across time and situations. To study these processes adequately, researchers therefore rely on repeated measurements collected during daily life rather than single, static assessments. These data streams are called intensive longitudinal data or time series data.
Why researchers use ambulatory assessment
Ambulatory assessment has become increasingly common in psychology, psychiatry, and behavioral science because it enables researchers to study psychological processes as they unfold over time in everyday settings. It is used to answer research questions about emotions, psychological well-being, social media use, pain, diet and nutrition, personality, and other study domains.
Compared to traditional research methods or data collection techniques (such as retrospective questionnaires or laboratory experiments), ambulatory assessment offers several distinct advantages. In particular, three key features are central to its growing use: high ecological validity, reduced retrospective bias, and the ability to study within-person dynamics.
Compared to traditional research methods or data collection techniques (such as retrospective questionnaires or laboratory experiments), ambulatory assessment offers several distinct advantages. In particular, three key features are central to its growing use: high ecological validity, reduced retrospective bias, and the ability to study within-person dynamics.
Ecological validity: studying people in their natural habitat
A central characteristic of ambulatory assessment is that it allows researchers to collect data in the environments where experiences naturally occur. Instead of studying participants in highly controlled laboratory settings, ambulatory assessment measures emotions, symptoms, behaviors, and cognition while people go about their daily routines: at home, at work, during social interactions, or while commuting.
This focus on natural contexts is important because many psychological phenomena are strongly shaped by situational factors. Emotions, stress responses, and symptoms often depend on the specific events, interactions, and environments people encounter throughout the day. Observing these processes within real-world contexts allows researchers to examine how psychological states vary across everyday situations and activities.
Ambulatory assessment therefore complements traditional laboratory experiments. While experimental studies remain essential for testing causal mechanisms through controlled manipulation, ambulatory assessment allows researchers to investigate how these mechanisms operate within the complexity of daily life, the context we ultimately want to understand and make claims about.
This focus on natural contexts is important because many psychological phenomena are strongly shaped by situational factors. Emotions, stress responses, and symptoms often depend on the specific events, interactions, and environments people encounter throughout the day. Observing these processes within real-world contexts allows researchers to examine how psychological states vary across everyday situations and activities.
Ambulatory assessment therefore complements traditional laboratory experiments. While experimental studies remain essential for testing causal mechanisms through controlled manipulation, ambulatory assessment allows researchers to investigate how these mechanisms operate within the complexity of daily life, the context we ultimately want to understand and make claims about.
Reduced recall bias: capturing momentary experiences
A second important feature of ambulatory assessment is that it reduces the influence of retrospective bias. Traditional surveys and clinical interviews often ask participants to summarize their experiences over longer periods of time, such as the past week or the past month. Providing such summaries requires individuals to recall and aggregate many experiences, which can introduce distortions in how events and feelings are remembered.
Ambulatory assessment takes a different approach, and pursues real-time data collection. In the case of Ecological Momentary Assessment (EMA) or Experience Sampling Methodology (ESM), participants typically report on their current state or very recent experiences, often multiple times per day. Because the time between the experience and the report is short, these measurements rely less on long-term memory and more on immediate evaluation. This helps limit well-known recall biases, such as the tendency to overemphasize particularly intense experiences (e.g., peak-end rule biases) or the influence of current mood on how past experiences are remembered (e.g., mood-congruent effects).
Importantly, not all ambulatory measurements rely on self-report. Modern protocols increasingly combine momentary surveys with passive data streams from smartphones or wearable devices, as well as mobile cognitive tasks administered directly on participants’ devices. These measurement approaches do not depend on retrospective recall at all. Instead, they capture behavioral, physiological, or cognitive signalsdirectly as they occur. Together, these modalities allow ambulatory assessment studies to obtain measurements that are closely aligned with the timing of the underlying processes or constructs being studied.
Ambulatory assessment takes a different approach, and pursues real-time data collection. In the case of Ecological Momentary Assessment (EMA) or Experience Sampling Methodology (ESM), participants typically report on their current state or very recent experiences, often multiple times per day. Because the time between the experience and the report is short, these measurements rely less on long-term memory and more on immediate evaluation. This helps limit well-known recall biases, such as the tendency to overemphasize particularly intense experiences (e.g., peak-end rule biases) or the influence of current mood on how past experiences are remembered (e.g., mood-congruent effects).
Importantly, not all ambulatory measurements rely on self-report. Modern protocols increasingly combine momentary surveys with passive data streams from smartphones or wearable devices, as well as mobile cognitive tasks administered directly on participants’ devices. These measurement approaches do not depend on retrospective recall at all. Instead, they capture behavioral, physiological, or cognitive signalsdirectly as they occur. Together, these modalities allow ambulatory assessment studies to obtain measurements that are closely aligned with the timing of the underlying processes or constructs being studied.
Within-person dynamics: understanding how processes unfold over time
A third key advantage of ambulatory assessment is that it enables researchers to study within-person dynamics. Traditional psychological research has largely adopted a nomothetic perspective, focusing on differences between individuals, comparing average levels of symptoms, emotions, or behaviors across participants. While these approaches are informative, they provide limited insight into how psychological processes change within the same person over time, which is the focus of an idiographic perspective.
Ambulatory assessment addresses this limitation by collecting repeated measurements for each participant, often multiple times per day across several days or weeks. These intensive longitudinal data make it possible to examine how emotions, symptoms, thoughts, and behaviors fluctuate within individuals, and how these changes relate to events or contextual factors in daily life.
Importantly, within-person dynamics do not necessarily mirror between-person patterns. Associations observed at the group level may differ from, or even reverse within individuals, a phenomenon known as Simpson’s paradox. As a result, relying solely on between-person analyses can obscure or misrepresent the processes that operate within individuals. This within-person perspective allows researchers to investigate questions that cannot be addressed with single-time-point measurements. For example, researchers can examine how stress at one moment predicts mood later in the day, how symptoms evolve across daily routines, or how individuals respond to specific experiences in their environment. By capturing these temporal patterns, ambulatory assessment provides a framework for studying psychological processes as dynamic systems that unfold across time and context.
Ambulatory assessment addresses this limitation by collecting repeated measurements for each participant, often multiple times per day across several days or weeks. These intensive longitudinal data make it possible to examine how emotions, symptoms, thoughts, and behaviors fluctuate within individuals, and how these changes relate to events or contextual factors in daily life.
Importantly, within-person dynamics do not necessarily mirror between-person patterns. Associations observed at the group level may differ from, or even reverse within individuals, a phenomenon known as Simpson’s paradox. As a result, relying solely on between-person analyses can obscure or misrepresent the processes that operate within individuals. This within-person perspective allows researchers to investigate questions that cannot be addressed with single-time-point measurements. For example, researchers can examine how stress at one moment predicts mood later in the day, how symptoms evolve across daily routines, or how individuals respond to specific experiences in their environment. By capturing these temporal patterns, ambulatory assessment provides a framework for studying psychological processes as dynamic systems that unfold across time and context.
What methods are included in ambulatory assessment?
Ambulatory assessment can be organized by the type of data researchers collect in daily life. Although many studies combine several methods, three broad categories are especially important: self-report, sensor data, and mobile cognitive assessment.
Self-report methods: ESM, EMA and daily diary
Self-report methods ask participants to answer short questions about their current or recent experiences. This includes methods such as the Experience Sampling Method (ESM), Ecological Momentary Assessment (EMA), and daily diary studies. ESM and EMA usually involve several brief surveys per day, while daily diary studies typically ask participants to reflect once per day. These methods are useful for measuring experiences that cannot be directly observed, such as mood, stress, pain, cravings, thoughts, symptoms, or social experiences.
Sensor-based methods: mobile and wearable sensing
Ambulatory assessment can also rely on sensor data collected through smartphones, wearables, or other connected devices. These data are often collected trough passive sensing, meaning they require little or no active input from participants. Examples include movement, location, physical activity, heartrate, sleep, phone use, ambient sound, or proximity to other devices. Sensor data can help researchers capture aspects of behavior, ambulatory psychophysiology, and context that are difficult to measure through questionnaires alone.
Mobile cognitive tests
A third approach involves short cognitive tasks completed on a smartphone or tablet. These tasks can be used to assess processes such as attention, memory, inhibition, reaction time, decision-making, or working memory. Unlike traditional cognitive testing, mobile cognitive assessment makes it possible to study cognitive functioning outside the lab, closer to the situations in which cognition is actually used. Combined with self-report and sensor data, it provides a more complete picture of daily functioning.
How does an ambulatory assessment study work?
An ambulatory assessment study usually follows a structured workflow, from study design to data collection and analysis. Although protocols differ depending on the research question, most studies involve the same core steps: defining what should be measured, deciding when and how often to measure it, selecting the appropriate technology, recruiting and onboarding participants, collecting data in daily life, and preparing the resulting intensive longitudinal data for analysis.
Define your research question and construct
The first step is to define the constructs and processes of interest. Researchers need to decide what they want to capture in daily life, such as mood, stress, pain, social interaction, physical activity, sleep, symptoms, or cognitive functioning. This choice determines which measurement methods are needed. Some constructs are best assessed through self-report, others through sensor data, and some through short mobile cognitive tasks.
Design the sampling protocol
Next, researchers design the sampling protocol. This involves deciding how long the study will last, how many assessments participants will receive per day, and when those assessments will be triggered. In Ecological Momentary Assessment (EMA) / Experience Sampling Methods (ESM) studies, prompts may be scheduled at fixed times, randomly within time blocks, or in response to specific events. Daily diary studies often use one assessment per day, usually in the evening. Sensor-based studies may collect data continuously, periodically, or only around specific assessment moments.
Build and pilot the ambulatory protocol
After the protocol is designed, the study is implemented in a digital platform or mobile app. Researchers build the questionnaires, configure notifications, set up sensors or wearable integrations, and define participant instructions. At this stage, it is important to test the protocol carefully to make sure prompts are triggered at the right moments, questionnaires or cognitive tasks work as intended, and data are stored correctly.
Recruit and onboard participants
Participants are then recruited and enrolled. During onboarding, they install the app, provide consent, receive instructions, and often complete some baseline surveys. Clear instructions are important because ambulatory assessment takes place outside the researcher’s direct supervision. Participants need to understand when to respond, what kind of situations to report on, and how to handle technical problems.
Collect data in daily life
During the data collection period, participants complete assessments in their daily lives while the system records responses, timestamps, completion times, and, when relevant, sensor or task data (e.g., hit rates or reaction times). Researchers may monitor coverage and compliance during the study and send reminders or follow-up messages when needed.
Clean and analyze the data
Finally, the data are cleaned, structured, and analyzed. Ambulatory assessment data often contain many repeated observations nested within individuals (i.e., time series data). Researchers need to check missingness, response delays, compliance, and timing before using statistical models that can account for the multilevel and time-dependent structure of the data.
Dr. Egon Dejonckheere
Egon Dejonckheere is an Assistant Professor at Tilburg University, affiliated with KU Leuven, specializing in ambulatory assessment and intensive longitudinal research. His work combines methodological innovation to improve these methods with applications in mental health and emotion dynamics, and includes dozens of smartphone-based studies in daily life.
FAQ
01.
What is ambulatory assessment in psychology?
Ambulatory assessment is an umbrella term for methods that measure psychological, behavioral, and physiological processes in real-world settings over time. It involves collecting time series data during daily life rather than relying on single, retrospective assessments.
02.
What methods are included in ambulatory assessment?
Ambulatory assessment includes approaches such as experience sampling methodology (ESM), ecological momentary assessment (EMA), and daily diary methods. It can also incorporate mobile sensing and wearable data to capture behavior and physiology, as well as cognitive tasks to assess momentary cognitive ability alongside self-report.
03.
How is ambulatory assessment different from traditional research methods?
Unlike traditional surveys or laboratory studies, ambulatory assessment collects data in real time and in natural environments. This allows researchers to study how processes unfold in daily life rather than relying on memory or artificial settings.
04.
What phenomena can be studied with ambulatory assessment?
Ambulatory assessment can capture data about awide range of topics, including emotions, thoughts, behaviors, symptoms, contextual factors, physiological signals, and cognitive performance. These data are often collected repeatedly to track changes over time.
05.
What are the advantages of ambulatory assessment?
Key advantages include high ecological validity, reduced recall bias, and the ability to study within-person changes over time. These features allow researchers to better understand how experiences and behaviors fluctuate in real-world contexts.
06.
What is the difference between ambulatory assessment and ESM or EMA?
Ambulatory assessment is the broader framework, while Experience Sampling Methodology (ESM) and Ecological Momenatary Assessment (EMA) are specific methods within it. ESM and EMA focus primarily on repeated self-report, whereas ambulatory assessment can also include passive sensing and other measurement approaches.