Summary
Thibaud et al. (Methods in Ecology and Evolution 2014) present a framework for simulating species and evaluating the relative effects of factors affecting the predictions from species ...distribution models (SDMs). They demonstrate their approach by generating presence–absence data sets for different simulated species and analysing them using four modelling methods: three presence–absence methods and Maxent, which is a presence‐background modelling tool. One of their results is striking: that their use of Maxent performs well in estimating occupancy probabilities and even outperforms the other methods on small sample sizes. This result is of concern to us, because it suggests that Maxent directly offers a useful alternative for modelling presence–absence data, which may prompt widespread adoption of this use of Maxent. In this paper, we explore why this would be a mistake.
We draw on the theory underlying how the Maxent model operates and on simulations to discover: (i) why Maxent appears to fare as well as it does in their evaluation and (ii) why the best‐suited presence–absence method for data analysis (the generating model; a GLM) does not perform as well as we would expect.
We demonstrate that (i) the good performance observed for Maxent is largely a coincidence; the simulated species match well the arbitrary default parameter that Maxent applies to map its relative output into a 0–1 scale, but errors are much larger for other species we simulate; (ii) the performance of the GLM is poorer than expected because Thibaud et al. do not use model selection and fit a model that is too complex for the amount of data available.
Maxent is a presence‐background method and only provides estimates of relative suitability regardless of how the background sample is specified. When presence–absence data are available, one can transform Maxent's relative estimates into estimates of occupancy probability, and we provide methods to do so. However, this requires the user to post‐process Maxent's output. Proper PA methods such as GLMs can perform well under small sample sizes, provided care is taken during modelling to avoid overfitting. We demonstrate an effective method using regularisation with the R package glmnet.
The Community of Inquiry (CoI) has provided a useful tool for studying technology-enhanced learning environments. It has also been implemented as the theoretical framework for many types of relevant ...research. Since its development, the framework has generated substantial interest among scholars in many fields such as distance education, online and blended learning and computed-mediated instruction. Although extensive research has been carried out on the CoI, no single study has been conducted that statistically and mathematically examines all publications of the framework. This study aimed to comprehensively review more than two decades of publications on the CoI framework by applying the bibliometric analysis technique. Therefore, all the corresponding Scopus records (in total 5169) in the past 24 years (1999-2023) were analyzed using the VOSviewer, Bibliometrix, and CiteSpace tools. The study described various essential research indicators, such as the research categories (directions), most productive authors, journals, institutions, and countries, along with potential research hotspots. The thematic analysis highlighted the research themes that have attracted scholars in the field by visualization of the current CoI research landscape.
This study investigated how learners' perceived online presence contributed to their learning performance while participating in a blog-based university course. Although the literature evidently ...highlights that there is a necessity for online presence in online courses, concrete design approaches and empirical evaluation of the impact of online presence on learning performance in blog-based courses are lacking. An empirical study was therefore conducted to understand the relationship between individuals' perceptions of online presence, in terms of teaching, social and cognitive presences, and their learning performance, in terms of subjective and objective learning outcomes. Research questions were tested and data were analyzed using regression analysis. The results indicate that online presence has a significant influence on learning performance. A subsequent analysis found that cognitive presence played the most important role in blog-based online learning performance. This study also identified a significant relationship in learning performance between students' subjective and objective learning outcomes.
•We investigated effects of online presence on learning performance.•Online presence has a significant influence on learning performance.•Cognitive presence played the most important role in blog-based learning.•Students' subjective and objective learning outcomes are significantly related.
PurposeThe purpose of the present research was to examine the effects of content, spatial, temporal and social presences stimulated by augmented reality (AR) technology on game enjoyment and ...continuing behavioral intention.Design/methodology/approachA total of 355 mobile AR game players participated in an online survey posted via the nationwide crowdsourcing web service in the US. A structural equation modeling was conducted using a maximum-likelihood estimation procedure to test the relationships among the variables.FindingsResults of structural equation modeling revealed the mechanism through which multiple dimensions of presence on the mobile AR game generated positive effects on consumer responses and showed the effects of four dimensions of presence stimulated by the AR technology on game enjoyment, performance and behavioral intention. Content, spatial, temporal and social presences are integrated to create a sense of realness. These dimensions of presence simultaneously increased game enjoyment that influenced the perceived game performance, commitment to it and ultimately the intention to play other mobile AR games.Originality/valueAlthough AR technology brings a unique experience to the game player, research on the effects of its use in mobile games on consumer responses is currently limited. The results of this study add value to the existing mobile game literature and provide practical insights for mobile game service providers on how to enhance players’ game enjoyment and continuing behavior.
Summary
Presence‐only records may provide data on the distributions of rare species, but commonly suffer from large, unknown biases due to their typically haphazard collection schemes. ...Presence–absence or count data collected in systematic, planned surveys are more reliable but typically less abundant.
We proposed a probabilistic model to allow for joint analysis of presence‐only and survey data to exploit their complementary strengths. Our method pools presence‐only and presence–absence data for many species and maximizes a joint likelihood, simultaneously estimating and adjusting for the sampling bias affecting the presence‐only data. By assuming that the sampling bias is the same for all species, we can borrow strength across species to efficiently estimate the bias and improve our inference from presence‐only data.
We evaluate our model's performance on data for 36 eucalypt species in south‐eastern Australia. We find that presence‐only records exhibit a strong sampling bias towards the coast and towards Sydney, the largest city. Our data‐pooling technique substantially improves the out‐of‐sample predictive performance of our model when the amount of available presence–absence data for a given species is scarce
If we have only presence‐only data and no presence–absence data for a given species, but both types of data for several other species that suffer from the same spatial sampling bias, then our method can obtain an unbiased estimate of the first species' geographic range.
In this paper we examine the Community of Inquiry framework (
Garrison, Anderson, & Archer, 2000) suggesting that the model may be enhanced through a fuller articulation of the roles of online ...learners. We present the results of a study of 3165 students in online and hybrid courses from 42 two- and four-year institutions in which we examine the relationship between learner self-efficacy measures and their ratings of the quality of their learning in virtual environments. We conclude that a positive relationship exists between elements of the CoI framework and between elements of a nascent theoretical construct that we label “learning presence”. We suggest that learning presence represents elements such as self-efficacy as well as other cognitive, behavioral, and motivational constructs supportive of
online learner self-regulation. We suggest that this focused analysis on the active roles of online learners may contribute to a more thorough account of knowledge construction in technology-mediated environments expanding the descriptive and explanatory power of the Community of Inquiry framework. Learning presence: Towards a Theory of Self-efficacy, Self-regulation, and the Development of a Communities of Inquiry in Online and Blended Learning Environments.
► Articulates a new construct within the Community of Inquiry (CoI) Framework ► Describe “learning presence” as a new component of the CoI Model ► Learning presence - self and co-regulation of effective behaviors in online learning environments ► Learners' self efficacy, is associated with the environment in which they study ► Stronger correlation between self-efficacy and the quality of environment in hybrid courses.
ABSTRACT
In this article, we discuss and empirically examine the importance of embodiment, context, and spatial proximity as they pertain to collaborative interaction and task completion in virtual ...environments. Specifically, we introduce the embodied social presence (ESP) theory as a framework to account for a higher level of perceptual engagement that users experience as they engage in activity‐based social interaction in virtual environments. The ESP theory builds on the analysis of reflection data from Second Life users to explain the process by which perceptions of ESP are realized. We proceed to describe implications of ESP for collaboration and other organizational functions.
Social virtual reality (social VR) platforms are gaining popularity among users. Previous qualitative research suggests that feelings of presence can make these platforms an attractive environment to ...obtain social support from others. Building on these exploratory insights, we carried out a quantitative study to illuminate how different types of presence in social VR platforms facilitate social support. The results of a large survey conducted among users (N = 1231) show that feelings of social presence and self-presence are predictors of perceived social support and that this perception of social support is positively associated with users' subjective well-being. Perceived social support is greater for women than for men, and it differs across platforms, although with small effect sizes. These results underline the role of presence in the perception of computer-mediated social support, suggesting that the affordances of social VR make it a particularly well-suited medium for facilitating beneficial interactions among users.
•Feelings of social presence and self-presence predict perceived social support in social VR platforms.•Perceived social support in social VR platforms has an indirect association with subjective well-being.•Perceived social support in social VR platforms is greater for women than for men.•The results suggest that social interactions in immersive media may involve benefits for users' well-being.
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