Nikolaos Batalas
Eindhoven University of Technology
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Featured researches published by Nikolaos Batalas.
engineering interactive computing system | 2012
Nikolaos Batalas; Panos Markopoulos
Computerized tools for in-situ data collection from study participants have proven invaluable in many diverse fields. The platforms developed within academic settings, eventually tend to find themselves abandoned and obsolete. Newer tools are susceptible to meeting a similar fate. We believe this is because, although most of the tools try to satisfy the same functional requirements, little attention has been paid to their development models also keeping in line. In this paper we propose an architectural model, which satisfies established requirements and also promotes extensibility, interoperability and cross-platform functionality between tools. In doing so, we aim to introduce development considerations into the larger discussion on the design of such platforms.
european conference on cognitive ergonomics | 2015
Panos Markopoulos; Nikolaos Batalas; Aaa Annick Timmermans
This paper argues that allowing personalization can increase respondent adherence in experience sampling studies. We report a one week long field experiment (N=36), which compared response rates when respondents select the times at which they are prompted to report in an experience sampling protocol (experimental group), versus the situation where these times are selected by the experimenter (control group). Results showed that participants who could choose their time slots showed a significantly higher response rate than participants who received the questions on preset time slots (p=0.002). There was no difference in response rates for different times of the day. Social influence, as permitted through the personalization process is offered as one of the explanations for enhancing compliance to the experience sampling probes. Future research needs to establish whether this or other practical explanations regarding respondent convenience explain the increased adherence and whether the found effect can be sustained for longer studies.
ambient intelligence | 2012
Nikolaos Batalas; Hester Bruikman; Annemiek van Drunen; He Huang; Dominika Turzynska; Vanessa Vakili; Natalia Voynarovskaya; Panos Markopoulos
We discuss a case study where this technique was used in the design of an ambient intelligence system, highlighting how it impacted the design process both in positive and negative ways. This contextualized account complements related comparative studies that have been conducted outside the context of a design project, and have focused on methodological aspects of video prototyping. We conclude that designers need to be aware of how video as a persuasive medium obfuscates implementation and usability issues, and video prototype production should communicate explicitly the scope of the design issues that it addresses and those it does not.
Contemporary clinical trials communications | 2017
Christien Slofstra; Nicola S. Klein; Maaike Nauta; Marieke Wichers; Nikolaos Batalas; Claudi Bockting
Background Relapse prevention strategies include continuation of antidepressant medication and preventive psychological interventions. This study aims to gain understanding that may inform tailoring of relapse prevention to individual differences, to improve their effects. Such treatment personalization may be based on repeated assessments within one individual, using experience sampling methodology. As a first step towards informing decisions based on this methodology, insight is needed in individual differences in risk of relapse and response to treatment, and how relapse prevention strategies may differentially target vulnerability for relapse. Methods The smartphone application ‘Imagine your mood’ has been developed specifically for this study to assess emotions, imagery, cognitions, and behaviors in daily life. Parallel to the randomized controlled trial ‘Disrupting the rhythm of depression’, 45 remitted recurrently depressed individuals taking continuation antidepressant medication will be randomly assigned to either continuing antidepressant medication (n = 15), continuing antidepressant medication combined with an eight-session preventive cognitive therapy (n = 15), or tapering of antidepressant medication in combination with preventive cognitive therapy (n = 15). Relapse and return of depressive symptomatology over a 24-month follow-up will be assessed. Additionally, matched never depressed individuals (n = 15) will be recruited as controls. Discussion This innovative study combines the strengths of a randomized controlled trial and experience sampling methodology in a micro-trial to explore individual differences in risk of relapse and what works for whom to prevent relapse. Results may ultimately pave the way for therapists to tailor relapse prevention strategies to individual (affective) vulnerability. Trial registration ISRCTN15472145, retrospectively registered.
Computers in Human Behavior | 2017
Arief Ernst Hhn; Vassilis-Javed Khan; P.E. Ketelaar; Jonathan van ‘t Riet; Ruben Konig; Esther Rozendaal; Nikolaos Batalas; Panos Markopoulos
We investigate the effect of location-congruent mobile messages on perceived intrusiveness, value, and relevance through a field experiment using the Experience Sampling Method (ESM). We developed a mobile application for undergraduate students, featuring campus news and information concerning class schedules. This application also included daily ads for the University restaurant, which were either location-(semi)congruent or location-incongruent. Immediately after viewing the ads the app presented a short questionnaire to the participants for a period of four weeks, thereby measuring their perceived intrusiveness, relevance and value of these ads. During these four weeks daily ads were sent to 40 students, resulting in 107 responses from 23 participants. The results show that our participants perceived location-(semi)congruent ads as significantly more valuable and relevant, whereas no significant results were found for perceived intrusiveness. By investigating LBA in a field-study based on ESM utilizing participants own smartphone devices this study corroborates the presumed effects of location-(semi)congruency on marketing relevant ad perceptions. Field experiment examines how individuals react to Location-Based Ads (LBAs).In situ data collection via ESM using a context-triggered sampling design.Location (semi)congruency has a positive influence on perceived relevance and value.LBA has no significant influence on perceived ad intrusiveness.Intra-individual variations are significant with all three dependent variables.
australasian computer-human interaction conference | 2014
Suzanne Kieffer; Nikolaos Batalas; Panos Markopoulos
This paper discusses challenges in contextual task analysis and the need of tools that support analysts to collect such information in context. Specifically we argue that the analysis of collaborative and distributed tasks can be supported by ambulatory assessment tools. We illustrate how contextual task analysis can be supported by TEMPEST, a platform originally created for experience sampling and more generally, longitudinal ambulatory assessment studies. We present a case study that illustrates the extent to which this tool meets the needs of real-world task analysis, describing the gains in efficiency it can provide but also directions for the development of tool support for task analysis.
Cognition & Emotion | 2018
Christien Slofstra; Maaike Nauta; Emily A. Holmes; Elisabeth H. Bos; Marieke Wichers; Nikolaos Batalas; Nicola S. Klein; Claudi Bockting
ABSTRACT Previously depressed individuals experience disturbances in affect. Affective disturbances may be related to visual mental imagery, given that imagery-based processing of emotional stimuli causes stronger affective responses than verbal processing in experimental laboratory studies. However, the role of imagery-based processing in everyday life is unknown. This study assessed mental imagery in the daily life of previously and never depressed individuals. Higher levels of visual mental imagery was hypothesised to be associated with more affective reactivity to both negatively and positively valenced mental representations. This study was the first to explore mental imagery in daily life using experience sampling methodology. Previously depressed (n = 10) and matched never depressed (n = 11) individuals participated in this study. Momentary affect and imagery-based processing were assessed using the “Imagine your mood” smartphone application. Participants recorded on average 136 momentary reports over a period of 8 weeks. The expected association between visual mental imagery and affective reactivity was not found. Unexpectedly, in both previously and never depressed individuals, higher levels of imagery-based processing of mental representations in daily life were significantly associated with better momentary mood and more positive affect, regardless of valence. The causality of effects remains to be examined in future studies.
Psychotherapy and Psychosomatics | 2018
Christien Slofstra; Maaike Nauta; Laura F. Bringmann; Nicola S. Klein; Casper J. Albers; Nikolaos Batalas; Marieke Wichers; Claudi Bockting
The primary aim of this study (see Slofstra et al. [6] for details on the design) is to explore, using experience sampling methodology (ESM), whether individual negative affective trajectories can be detected in remitted previously depressed individuals undergoing different relapse prevention treatments. It was hypothesized that affective trajectories would vary from person to person. A second aim was to tentatively explore whether these individual trajectories during treatment may be relevant for subsequent depressive relapse. It was hypothesized that increases in mean negative affect or negative affective inertia would be discerned in a subset of individuals that relapsed. Furthermore, decreases in mean negative affect or negative affective inertia were hypothesized to signal decreased vulnerability for depressive relapse. Affect was repeatedly assessed in daily life for 8 weeks, using ESM. Sufficient assessments to be eligible for analyses were provided by 42 (out of 72) previously depressed participants, and 11 (out of 15) matched never depressed controls. Previously depressed individuals had been randomly assigned to continuation of antidepressants (n = 10), continuation of antidepressants with preventive cognitive therapy (n = 15), or tapering of antidepressants with preventive cognitive therapy (n = 17). To explore whether individual trajectories in negative affect can be detected, the presence of significant change in mean negative affect or negative affective inertia was analysed per individual [10]. Additional information about the methods and results can be found in the supplemental materials (for all online suppl. material, see www.karger.com/doi/10.1159/000489044). Table 1 summarizes the changes in mean negative affect or negative affective inertia per group. These results show that individual trajectories while receiving various relapse prevention treatments can be detected and that these affective changes indeed vary from person to person. As a striking example, 2 individuals in 1 group experienced increases in mean negative affect while 2 others experienced decreases. Finally, 1 never depressed individual participant from the matched control group demonstrated decreased negative affective inertia. For the secondary aim of this study, it was descriptively explored whether individual affective trajectories are related to depressive relapse as assessed using repeated clinical interviews over 15 months. The expected increases in mean negative affect were observed in 2 (out of 42 = 5%) previously depressed individuals, both of whom relapsed. However, no increases in negative affective inertia were observed in any previously depressed individuals, including those who relapsed at the end or soon after the ESM study period. Of the 42 previously depressed participants, 22 relapsed (52%). Thus, increases in mean negative affect were observed in a small minority of previously depressed individuals that relapsed (2 out of 22 = 9%). Nine previously depressed individuals displayed decreases in mean negative affect or negative affective inertia (21%). Of these 9 individuals, 5 (56%) did subsequently relapse. Unexpectedly, a decrease in negative affective inertia co-occurred Meta-analyses demonstrate that different relapse prevention strategies, including continuation of antidepressant medication [1], preventive psychological therapy [2], or the combination of both [3] reduce the risk of relapse at a group level. However, the average effect of a treatment does not apply to every individual in that group [4], and many individuals experience a subsequent episode despite their use of relapse prevention strategies [3]. One of the current challenges is to personalize relapse prevention strategies [5]. For advancing personalized relapse prevention strategies, zooming into within-individual affective trajectories may be the way forward [6]. Within-individual affective changes may characterize transitions into and out of a depressive state [7]. It is hypothesized that these transitions differ from person to person, that gradual transitions into a depressive state are characterized by increases in mean negative affect, and that abrupt transitions into a depressive state are preceded by increased negative affective inertia [8]. Negative affective inertia refers to the degree one’s affect is predictive of itself over time and thus indicates that current levels of negative affect predict negative affect levels at the next time point [9]. The empirical support for these hypotheses is limited though promising and suggests that increased affective inertia may indeed signal an abrupt transition into a depressive state [7]. However, to our knowledge, no studies to date examined whether significant within-individual affective change could be detected in a group of previously depressed individuals undergoing different relapse prevention strategies. Received: July 4, 2017 Accepted after revision: April 4, 2018 Published online: May 14, 2018
Psychopathology | 2018
Renske C. Bosman; Casper J. Albers; Jettie de Jong; Nikolaos Batalas; Marije aan het Rot
Background/Aims: Before diagnosing premenstrual dysphoric disorder (PMDD), 2 months of prospective assessment are required to confirm menstrual cyclicity in symptoms. For a diagnosis of premenstrual syndrome (PMS), this is not required. Women with PMDD and PMS often report that their symptoms interfere with mood and social functioning, and are said to show cyclical changes in interpersonal behaviour, but this has not been examined using a prospective approach. We sampled cyclicity in mood and interpersonal behaviour for 2 months in women with self- reported PMS. Methods: Participants met the criteria for PMS on the Premenstrual Symptoms Screening Tool (PSST), a retrospective questionnaire. For 2 menstrual cycles, after each social interaction, they used the online software TEMPEST to record on their smartphones how they felt and behaved. We examined within-person variability in negative affect, positive affect, quarrelsomeness, and agreeableness. Results: Participants evaluated TEMPEST as positive. However, we found no evidence for menstrual cyclicity in mood and interpersonal behaviour in any of the individual women (n = 9). Conclusion: Retrospective questionnaires such as the PSST may lead to oversampling of PMS. The diagnosis of PMS, like that of PMDD, might require 2 months of prospective assessment.
Proceedings of the ACM on Human-Computer Interaction | 2018
Nikolaos Batalas; Marije aan het Rot; Vassilis-Javed Khan; Panos Markopoulos
Researchers who perform Ecological Momentary Assessment (EMA) studies tend to rely on informatics experts to set up and administer their data collection protocols with digital media. Contrary to standard surveys and questionnaires that are supported by widely available tools, setting up an EMA protocol is a substantial programming task. Apart from constructing the survey items themselves, researchers also need to design, implement, and test the timing and the contingencies by which these items are presented to respondents. Furthermore, given the wide availability of smartphones, it is becoming increasingly important to execute EMA studies on user-owned devices, which presents a number of software engineering challenges pertaining to connectivity, platform independence, persistent storage, and back-end control. We discuss TEMPEST, a web-based platform that is designed to support non-programmers in specifying and executing EMA studies. We discuss the conceptual model it presents to end-users, through an example of use, and its evaluation by 18 researchers who have put it to real-life use in 13 distinct research studies.