Pejman Sajjadi

dblp:143/5348 · DBLP profile ↗
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9ranked-venue papers
2as first author
4since 2021 · last 2024
0000-0001-8761-7705ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Human-computer interaction and ubiquitous computing · 9 · 2 first-author · 4 since 2021Applied, interdisciplinary, general and emerging computing · 5 · 2 first-author · 2 since 2021Graphics, computer vision, multimedia, augmented reality and games · 3 · 1 since 2021
YearPublicationVenuePosition
2024 Preventing users from going down rabbit holes of extreme video content: A study of the role played by different modes of autoplay
Cheng Chen 0067, Jingshi Kang, Pejman Sajjadi, S. Shyam Sundar
Int. J. Hum. Comput. Stud.3
2021 Influence of HMD Type and Spatial Ability on Experiences and Learning in Place-based Education
abstract
With the emergence of different types of Head-Mounted Displays (HMDs), researchers and educators must make informed decisions on what HMDs best support their needs. When performing experiments with relatively large populations, these decisions are largely affected by the sensing-scaling tradeoff between high-end tethered HMDs and lower-end standalone systems. Higher sensing affords a richer experience, but it is also associated with higher costs in terms of the HMD itself and the need for VR-ready computers. These limitations often impede instructors from using high-end HMDs in an efficient way with larger populations. We report on the results of a study in the context of place-based immersive VR (iVR) Geoscience education that compares the experiences and learning of 45 students after going through an immersive virtual field trip, using either a lower-sensing but scalable Oculus Quest or a higher-sensing but tethered HTC Vive Pro. Our results indicate that students who used the Quest reported significantly higher levels of satisfaction but also more simulator sickness (although still a very low number on average) compared to those who used an HTC Vive Pro. Our findings suggest that with content design considerations, standalone HMDs can be a viable replacement for high-end systems in large-scale studies. Furthermore, our results also suggest that in the context of place-based iVR education, the spatial abilities of students (i.e., sense-of-direction) can be a determining factor in their experiences and learning, and therefore an important topic of study for designing effective place-based iVR experiences.
Pejman Sajjadi, Jiayan Zhao, Jan Oliver Wallgrün, Peter La Femina, Alexander Klippel
iLRN1
2021 Place-Based Learning Through a Proxy - Variations in the Perceived Benefits of a Virtual Tour
abstract
Place-based and fieldwork learning play a key role in higher education in environmental sciences and other geospatial disciplines. We report on a study in which we evaluated a web-based virtual tour application for teaching natural resource management in fire-prone western forests in two undergraduate classes. The virtual tour uses 360°-image-based virtual scenes and pre-recorded audio commentary by a domain expert to lead participants through the Stanislaus-Tuolumne Experimental Forest where forest treatments were implemented to reduce fire hazard. We present results from assessing students' overall perception of the virtual tour, their views towards its application in undergraduate education, and their feedback for improving the design of future virtual tours. Furthermore, we discuss the collected data from the perspective of gender differences and differences in familiarity with the topic of the tour.
Jan Oliver Wallgrün, Eric Knapp, Alan Taylor, Alexander Klippel, Jiayan Zhao, Pejman Sajjadi
iLRN6
2021 CrowdXR - Pitfalls and Potentials of Experiments with Remote Participants
abstract
Although the COVID-19 pandemic has made the need for remote data collection more apparent than ever, progress has been slow in the virtual reality (VR) research community, and little is known about the quality of the data acquired from crowdsourced participants who own a head-mounted display (HMD), which we call crowdXR. To investigate this problem, we report on a VR spatial cognition experiment that was conducted both in-lab and out-of-lab. The in-lab study was administered as a traditional experiment with undergraduate students and dedicated VR equipment. The out-of-lab study was carried out remotely by recruiting HMD owners from VR-related research mailing lists, VR subreddits in Reddit, and crowdsourcing platforms. Demographic comparisons show that our out-of-lab sample was older, included more males, and had a higher sense of direction than our in-lab sample. The results of the involved spatial memory tasks indicate that the reliability of the data from out-of-lab participants was as good as or better than their in-lab counterparts. Additionally, the data for testing our research hypotheses were comparable between in- and out-of-lab studies. We conclude that crowdsourcing is a feasible and effective alternative to the use of university participant pools for collecting survey and performance data for VR research, despite potential design issues that may affect the generalizability of study results. We discuss the implications and future directions of running VR studies outside the laboratory and provide a set of practical recommendations.
Jiayan Zhao, Mark B. Simpson, Pejman Sajjadi, Jan Oliver Wallgrün, Ping Li 0026, Mahda M. Bagher, Danielle Oprean, Lace M. K. Padilla, Alexander Klippel
ISMAR3
2020 Fostering Penetrative Thinking in Geosciences Through Immersive Experiences: A Case Study in Visualizing Earthquake Locations in 3D
abstract
Thinking in and understanding of three-dimensional structures is omnipresent in many sciences from chemistry to geosciences. Current visualizations, however, are still using two-dimensional media such as maps or three-dimensional representations accessible through two-dimensional interfaces (e.g., desktop computers). The emergence of immersive virtual reality environments, both accessible and of high-quality, allows for creating embodied and interactive experiences that permit for rethinking learning environments and provide access to three-dimensional information through three-dimensional interfaces. However, there is a shortage of empirical studies on immersive learning environments. In response to this shortcoming, this study examines the role of immersive VR (iVR) in improving students' learning experience and performance in terms of penetrative thinking in a critical 3D task in geosciences education: drawing cross-sections. We developed a pilot study where students were asked to draw cross-sections of the depth and geometry of earthquakes at two subduction zones after visualizing the earthquake locations either in iVR or 2D maps on a computer. The results of our study show that iVR creates a better learning experience; students reported significantly higher scores in terms of Spatial Situation Model and there is anecdotal evidence in favor of higher reflective thinking in iVR. In terms of learning performance, we did not find a significant difference in the graded exercise of drawing cross-sections. However, iVR seems to have a positive effect on understanding the geometry of earthquake locations in a complex tectonic environment such as Japan. Our results, therefore, add to the growing body of literature that draws a more nuanced picture of the benefits of immersive learning environments calling for larger scale and in-depth studies.
Mahda M. Bagher, Pejman Sajjadi, Julia Carr, Peter La Femina, Alexander Klippel
iLRN2
2020 Mixed or Virtual: Does Device Type Matter in Human-ECA Interactions
abstract
In this paper, we take a first step in exploring the effect of xR devices on the experiences of users in the context of human-agent interactions. We report on the design and heuristic evaluation of an embodied conversational agent integrated into either a Virtual or Mixed Reality environment. Our evaluation with four experts show that Virtual Reality may elicit a better experience from users, while Mixed Reality may evoke a better sense of social presence due to natural user embodiment and spatial references to physical objects in the real environment.
Pejman Sajjadi, Mahda M. Bagher, Jan Oliver Wallgrün, Stefan Kopp, Philipp Cimiano, Alexander Klippel
iLRN1
2020 A Comparison of Visual Attention Guiding Approaches for 360° Image-Based VR Tours
abstract
Mechanisms for guiding a user’s visual attention to a particular point of interest play a crucial role in areas such as collaborative VR and AR, cinematic VR, and automated or live guided tour experiences in xR-based education. The attention guiding mechanism serves as a communication tool that helps users find entities currently not visible in their view, referenced for instance by another user or in some accompanying audio commentary. We report on a user study in which we compared three different visual guiding mechanisms (arrow, butterfly guide, and radar) in the context of 360° image-based educational VR tour applications of real-world sites. A fourth condition with no guidance tool available was added as a baseline. We investigate the question: How do the different approaches compare in terms of target finding performance and participants’ assessments of the experiences. While all three mechanisms were perceived as improvements over the no-guidance condition and resulted in significantly improved target finding times, the arrow mechanism stands out as the most generally accepted and favored approach, whereas the other two (butterfly guide and radar) received a more polarized assessment due to their specific strengths and drawbacks.
Jan Oliver Wallgrün, Mahda M. Bagher, Pejman Sajjadi, Alexander Klippel
VR3
2020 Learning in the Field: Comparison of Desktop, Immersive Virtual Reality, and Actual Field Trips for Place-Based STEM Education
abstract
Field trips are a key component of learning in STEM disciplines such as geoscience to develop skills, integrate knowledge, and prepare students for lifelong learning. Given the reported success of technology-based learning and the prevalence of new forms of technology, especially with immersive virtual reality (iVR) entering the mainstream, virtual field trips (VFTs) are increasingly being considered as an effective form of teaching to either supplement or replace actual field trips (AFTs). However, little research has investigated the implications of VFTs in place-based STEM education, and empirical evidence is still limited about differences between students’ learning experiences and outcomes in VFTs experienced on desktop displays and field trips experienced in iVR. We report on a study that divided an introductory geoscience laboratory course into three groups with the first two groups experiencing a VFT either on desktop (dVFT) or in iVR (iVFT), while the third group went on an AFT. We compared subjective experiences (assessed via questionnaires) and objective learning outcomes for these groups. Our results suggest that, although students reported higher motivation and being more present in the iVFT group, they did not learn more compared to those in the dVFT group; both VFT groups yielded higher scores for learning experience and perceived learning outcomes than the actual field site visit. These findings demonstrate positive learning effects of VFTs relative to AFTs and provide evidence that geology VFTs need not be limited to iVR setups, which lead to considerable equipment costs and increased implementation complexity. Discussing the results, we reflect on the implications of our findings and point out future research directions.
Jiayan Zhao, Peter C. LaFemina, Julia Carr, Pejman Sajjadi, Jan Oliver Wallgrün, Alexander Klippel
VR4
2019 Development and Evaluation of an Educational Game to Practice the Truth Tables of Logic
abstract
Already for years, the logic course in the first year of our Bachelor program in Computer Science has been a serious stumbling block for many students. They find the formal and abstract mechanisms of logic difficult and awkward to deal with. Many procrastinate, which results in poor understanding of the basic principles, which in turn causes them to fall even more behind. Previous attempts to remedy this have had little effect. Since educational games are deemed as an enjoyable way to foster learning, we decided to develop an educational game for the course. The game is a two-player competitive game inspired by an existing card game. We adapted this card game to proposition logic and digitized it as an app. The development was done in an iterative way. Each version was evaluated and based on the received feedback the software was improved and reevaluated. Based on the results of the evaluations we can conclude that the game is well suited for its target audience and is a good complement, and even replacement for some of the traditional face-to-face exercise sessions. However, we also noticed that making the game available without obligation to use was not the best approach. A good embedding into the course is needed to ensure that all students use the game. In this paper we present the game, explain and motivate its evolution, and present lessons learned.
Olga De Troyer, Renny S. N. Lindberg, Jan Maushagen, Pejman Sajjadi
ICALT4