Erkan Er, E. Gómez-Sánchez, Miguel L. Bote-Lorenzo, Juan I. Asensio-Pérez, Y. Dimitriadis
With the aim of supporting instructional designers in setting up collaborative learning activities in MOOCs, this paper derives prediction models for student participation in group discussions. The salient feature of these models is that they are built using only data prior to the learning activity, and can thus provide actionable predictions, as opposed to post-hoc approaches common in the MOOC literature. Some learning design scenarios that make use of this actionable information are illustrated.
{"title":"Informing the Design of Collaborative Activities in MOOCs using Actionable Predictions","authors":"Erkan Er, E. Gómez-Sánchez, Miguel L. Bote-Lorenzo, Juan I. Asensio-Pérez, Y. Dimitriadis","doi":"10.1145/3330430.3333640","DOIUrl":"https://doi.org/10.1145/3330430.3333640","url":null,"abstract":"With the aim of supporting instructional designers in setting up collaborative learning activities in MOOCs, this paper derives prediction models for student participation in group discussions. The salient feature of these models is that they are built using only data prior to the learning activity, and can thus provide actionable predictions, as opposed to post-hoc approaches common in the MOOC literature. Some learning design scenarios that make use of this actionable information are illustrated.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88747458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geoffrey Angus, Richard Diehl Martinez, M. Stevens, A. Paepcke
The processes through which course selections accumulate into college pathways in US higher education is poorly instrumented for observation at scale. We offer an analytic toolkit, called Via, which transforms commonly available enrollment data into formal graphs that are amenable to interactive visualizations and computational exploration. We explain the procedures required to project enrollment records onto graphs, and then demonstrate the toolkit utilizing eighteen years of enrollment data at a large private research university. Findings complement prior research on academic search and offer powerful new means for making pathway navigation more efficient.
{"title":"Via: Illuminating Academic Pathways at Scale","authors":"Geoffrey Angus, Richard Diehl Martinez, M. Stevens, A. Paepcke","doi":"10.1145/3330430.3333623","DOIUrl":"https://doi.org/10.1145/3330430.3333623","url":null,"abstract":"The processes through which course selections accumulate into college pathways in US higher education is poorly instrumented for observation at scale. We offer an analytic toolkit, called Via, which transforms commonly available enrollment data into formal graphs that are amenable to interactive visualizations and computational exploration. We explain the procedures required to project enrollment records onto graphs, and then demonstrate the toolkit utilizing eighteen years of enrollment data at a large private research university. Findings complement prior research on academic search and offer powerful new means for making pathway navigation more efficient.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83913420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Kay, Colin Lambe, Tyler J. Nolan, Thomas M. Grello, Anthony F. Breitzman
Numerous studies have concluded that viewer retention decreases as video length increases. However, we are not aware of any prior work in which a set of longer MOOC (Massive Open Online Course) videos are compared with the same content split into multiple shorter videos. We are fortunate to be in the unique position to have two separate MOOCs that teach essentially the same content using two different platforms (the LEGO Mindstorms NXT and EV3 robots). In our NXT MOOC, videos are quite long, with over 20% of the videos having a running time of more than ten minutes. The EV3 MOOC has very similar content; EV3 MOOC scripts were written by modifying NXT scripts as appropriate. However, many of the EV3 lessons were split into two or three shorter videos in place of a single longer one. NXT videos that are very close in terms of both content and duration to EV3 videos have similar average percentage viewed. This suggests that the two populations watching the videos are similar and that we have a promising setup for analyzing the relationship between NXT lessons whose EV3 counterparts consist of multiple shorter videos. We present an analysis of our data, along with various interpretations some, but not all, of which support the "shorter videos are better" hypothesis.
许多研究得出结论，随着视频长度的增加，观众的留存率会下降。然而，我们不知道之前有任何研究将一组较长的MOOC (Massive Open Online Course)视频与将同一内容分成多个较短的视频进行比较。我们很幸运能够拥有两个独立的mooc，使用两个不同的平台(LEGO Mindstorms NXT和EV3机器人)教授本质上相同的内容。在我们的NXT MOOC中，视频非常长，超过20%的视频运行时间超过10分钟。EV3 MOOC有非常相似的内容;EV3 MOOC脚本是通过适当修改NXT脚本编写的。然而，许多EV3课程被分成两个或三个较短的视频，而不是一个较长的视频。NXT视频在内容和时长方面与EV3视频非常接近，其平均观看率相似。这表明观看视频的两个人群是相似的，并且我们有一个很好的设置来分析NXT课程之间的关系，这些课程的EV3对应课程由多个较短的视频组成。我们对我们的数据进行了分析，并给出了不同的解释，其中一些(但不是全部)支持“视频越短越好”的假设。
{"title":"Apples to Apples: Differences in Viewer Retention When Longer Content is Chopped into Smaller Bites","authors":"J. Kay, Colin Lambe, Tyler J. Nolan, Thomas M. Grello, Anthony F. Breitzman","doi":"10.1145/3330430.3333617","DOIUrl":"https://doi.org/10.1145/3330430.3333617","url":null,"abstract":"Numerous studies have concluded that viewer retention decreases as video length increases. However, we are not aware of any prior work in which a set of longer MOOC (Massive Open Online Course) videos are compared with the same content split into multiple shorter videos. We are fortunate to be in the unique position to have two separate MOOCs that teach essentially the same content using two different platforms (the LEGO Mindstorms NXT and EV3 robots). In our NXT MOOC, videos are quite long, with over 20% of the videos having a running time of more than ten minutes. The EV3 MOOC has very similar content; EV3 MOOC scripts were written by modifying NXT scripts as appropriate. However, many of the EV3 lessons were split into two or three shorter videos in place of a single longer one. NXT videos that are very close in terms of both content and duration to EV3 videos have similar average percentage viewed. This suggests that the two populations watching the videos are similar and that we have a promising setup for analyzing the relationship between NXT lessons whose EV3 counterparts consist of multiple shorter videos. We present an analysis of our data, along with various interpretations some, but not all, of which support the \"shorter videos are better\" hypothesis.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81920314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ability to work in teams is an important skill in today's work environments. In MOOCs, however, team work, team tasks, and graded team-based assignments play only a marginal role. To close this gap, we have been exploring ways to integrate graded team-based assignments in MOOCs. Some goals of our work are to determine simple criteria to match teams in a volatile environment and to enable a frictionless online collaboration for the participants within our MOOC platform. The high dropout rates in MOOCs pose particular challenges for team work in this context. By now, we have conducted 15 MOOCs containing graded team-based assignments in a variety of topics. The paper at hand presents a study that aims to establish a solid understanding of the participants in the team tasks. Furthermore, we attempt to determine which team compositions are particularly successful. Finally, we examine how several modifications to our platform's collaborative toolset have affected the dropout rates and performance of the teams.
{"title":"Graded Team Assignments in MOOCs: Effects of Team Composition and Further Factors on Team Dropout Rates and Performance","authors":"T. Staubitz, C. Meinel","doi":"10.1145/3330430.3333619","DOIUrl":"https://doi.org/10.1145/3330430.3333619","url":null,"abstract":"The ability to work in teams is an important skill in today's work environments. In MOOCs, however, team work, team tasks, and graded team-based assignments play only a marginal role. To close this gap, we have been exploring ways to integrate graded team-based assignments in MOOCs. Some goals of our work are to determine simple criteria to match teams in a volatile environment and to enable a frictionless online collaboration for the participants within our MOOC platform. The high dropout rates in MOOCs pose particular challenges for team work in this context. By now, we have conducted 15 MOOCs containing graded team-based assignments in a variety of topics. The paper at hand presents a study that aims to establish a solid understanding of the participants in the team tasks. Furthermore, we attempt to determine which team compositions are particularly successful. Finally, we examine how several modifications to our platform's collaborative toolset have affected the dropout rates and performance of the teams.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80434296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maletsabisa Molapo, C. S. Moodley, I. Akhalwaya, Toby Kurien, Jay Kloppenberg, R. Young
In low-resource, over-burdened schools and learning centres, peer assessment systems promise significant practical and pedagogical benefits. Many of the these benefits have been realised in contexts like massive open online courses (MOOCs) and university classrooms which share a specific trait with low-resource schools: high learner-teacher ratios. However, the constraints and considerations for designing and deploying peer assessment systems in low-resource classrooms have not been well-researched and understood, especially for high school. In this paper, we present the design of a peer assessment system for second language learning (English as a Second Language) for high school learners in South Africa. We report findings from multiple studies investigating qualitative and quantitative aspects of peer review, as well as the contextual factors that influence the viability of peer assessment systems in these contexts.
{"title":"Designing Digital Peer Assessment for Second Language Learning in Low Resource Learning Settings","authors":"Maletsabisa Molapo, C. S. Moodley, I. Akhalwaya, Toby Kurien, Jay Kloppenberg, R. Young","doi":"10.1145/3330430.3333626","DOIUrl":"https://doi.org/10.1145/3330430.3333626","url":null,"abstract":"In low-resource, over-burdened schools and learning centres, peer assessment systems promise significant practical and pedagogical benefits. Many of the these benefits have been realised in contexts like massive open online courses (MOOCs) and university classrooms which share a specific trait with low-resource schools: high learner-teacher ratios. However, the constraints and considerations for designing and deploying peer assessment systems in low-resource classrooms have not been well-researched and understood, especially for high school. In this paper, we present the design of a peer assessment system for second language learning (English as a Second Language) for high school learners in South Africa. We report findings from multiple studies investigating qualitative and quantitative aspects of peer review, as well as the contextual factors that influence the viability of peer assessment systems in these contexts.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78781093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Formative feedback has long been recognized as a crucial scaffold for student learning. Due to the job demand of instructors, it is impossible for them to provide individual students with on-demand formative feedback based on individual students' performance. There is a growing interest in developing better approaches to provide students with automated formative feedback to assist their learning. In this research, we design and develop an automated formative feedback system to support student learning of conceptual knowledge in the course of writing assignments. In the proposed system, formative feedback can be generated automatically with the help of concept maps constructed from instructors' lecture slides and students' writing assignments. In this paper, we present the automatic approach to generate formative feedback, discuss the system architecture, and illustrate a prototype of the proposed system.
{"title":"An Automated Feedback System to Support Student Learning in Writing-to-Learn Activities","authors":"Ye Xiong, Y. Wu","doi":"10.1145/3330430.3333657","DOIUrl":"https://doi.org/10.1145/3330430.3333657","url":null,"abstract":"Formative feedback has long been recognized as a crucial scaffold for student learning. Due to the job demand of instructors, it is impossible for them to provide individual students with on-demand formative feedback based on individual students' performance. There is a growing interest in developing better approaches to provide students with automated formative feedback to assist their learning. In this research, we design and develop an automated formative feedback system to support student learning of conceptual knowledge in the course of writing assignments. In the proposed system, formative feedback can be generated automatically with the help of concept maps constructed from instructors' lecture slides and students' writing assignments. In this paper, we present the automatic approach to generate formative feedback, discuss the system architecture, and illustrate a prototype of the proposed system.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86388539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ángel Pérez-Lemonche, J. Stewart, Byron Drury, Rachel Henderson, Alexander J. Shvonski, David E. Pritchard
In principle, learning can be increased by assessing the detailed state of student knowledge and mistaken knowledge with a pre-test and then optimizing instruction as measured by the post-test score. As a first step in this direction, we applied a Multidimensional Item Response Theory (MIRT) to 17,000 pre-instruction administrations of the Force Concept Inventory (FCI) to study students' initial knowledge in detail. Examination of Item Response Curves (IRCs) showed that even students scoring below chance are not randomly guessing, but instead preferentially select only one or two distractors. Two dimensional IRT applied to the entire set of 150 possible responses, rather than applied dichotomously to the thirty questions, revealed two skill dimensions of comparable variance. Perpendicular directions were identified within this space corresponding to Newtonian ability and propensity to select responses whose IRC's have a maximum at intermediate Newtonian ability rather than at the top of bottom of this dimension. These intermediate responses corresponded to known pre-Newtonian ideas, particularly the Medieval concept of impetus. The ability to measure the detailed misconceptions of individual students or classes will allow development and application of instructional interventions for such specific misunderstandings, which are typically unchanged by traditional instruction.
{"title":"Mining Students Pre-instruction Beliefs for Improved Learning","authors":"Ángel Pérez-Lemonche, J. Stewart, Byron Drury, Rachel Henderson, Alexander J. Shvonski, David E. Pritchard","doi":"10.1145/3330430.3333637","DOIUrl":"https://doi.org/10.1145/3330430.3333637","url":null,"abstract":"In principle, learning can be increased by assessing the detailed state of student knowledge and mistaken knowledge with a pre-test and then optimizing instruction as measured by the post-test score. As a first step in this direction, we applied a Multidimensional Item Response Theory (MIRT) to 17,000 pre-instruction administrations of the Force Concept Inventory (FCI) to study students' initial knowledge in detail. Examination of Item Response Curves (IRCs) showed that even students scoring below chance are not randomly guessing, but instead preferentially select only one or two distractors. Two dimensional IRT applied to the entire set of 150 possible responses, rather than applied dichotomously to the thirty questions, revealed two skill dimensions of comparable variance. Perpendicular directions were identified within this space corresponding to Newtonian ability and propensity to select responses whose IRC's have a maximum at intermediate Newtonian ability rather than at the top of bottom of this dimension. These intermediate responses corresponded to known pre-Newtonian ideas, particularly the Medieval concept of impetus. The ability to measure the detailed misconceptions of individual students or classes will allow development and application of instructional interventions for such specific misunderstandings, which are typically unchanged by traditional instruction.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"300 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74410951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noah Bilgrien, Roy Finkelberg, Chirag Tailor, India Irish, Girish Murali, Abhishek Mangal, Niklas Gustafsson, Sumedha Raman, Thad Starner, R. Arriaga
We introduce PARQR, a tool for online education forums that reduces duplicate posts by 40% in a degree seeking online masters program at a top university. Instead of performing a standard keyword search, PARQR monitors questions as students compose them and continuously suggests relevant posts. In testing, PARQR correctly recommends a relevant post, if one exists, 73.5% of the time. We discuss PARQR's design, initial experimental results comparing different semesters with and without PARQR, and interviews we conducted with teaching instructors regarding their experience with PARQR.
{"title":"PARQR: Augmenting the Piazza Online Forum to Better Support Degree Seeking Online Masters Students","authors":"Noah Bilgrien, Roy Finkelberg, Chirag Tailor, India Irish, Girish Murali, Abhishek Mangal, Niklas Gustafsson, Sumedha Raman, Thad Starner, R. Arriaga","doi":"10.1145/3330430.3333662","DOIUrl":"https://doi.org/10.1145/3330430.3333662","url":null,"abstract":"We introduce PARQR, a tool for online education forums that reduces duplicate posts by 40% in a degree seeking online masters program at a top university. Instead of performing a standard keyword search, PARQR monitors questions as students compose them and continuously suggests relevant posts. In testing, PARQR correctly recommends a relevant post, if one exists, 73.5% of the time. We discuss PARQR's design, initial experimental results comparing different semesters with and without PARQR, and interviews we conducted with teaching instructors regarding their experience with PARQR.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87275132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
How do we design technology for learning at scale? Based on an examination of a large number of influential systems for learning at scale, I argue that designing for scale is not an amorphous design undertaking. Instead, it builds on two distinct perspectives on scale. Systems built with a scaling through efficiency perspective make learning more efficient and allow the same number of instructors to help a much larger set of learners. Systems with a scaling through empowerment perspective empower a larger number of people to assist learners effectively. I outline how these simple differences in design perspective lead to large differences in design concerns, techniques, and evaluation criteria. Articulating prevalent design perspectives should make overlooked design opportunities more salient, help systems designers design for scale more deliberately and understand their tradeoffs, and open up new opportunities to designers who shift their perspectives.
{"title":"Design Perspectives of Learning at Scale: Scaling Efficiency and Empowerment","authors":"Chinmay Kulkarni","doi":"10.1145/3330430.3333620","DOIUrl":"https://doi.org/10.1145/3330430.3333620","url":null,"abstract":"How do we design technology for learning at scale? Based on an examination of a large number of influential systems for learning at scale, I argue that designing for scale is not an amorphous design undertaking. Instead, it builds on two distinct perspectives on scale. Systems built with a scaling through efficiency perspective make learning more efficient and allow the same number of instructors to help a much larger set of learners. Systems with a scaling through empowerment perspective empower a larger number of people to assist learners effectively. I outline how these simple differences in design perspective lead to large differences in design concerns, techniques, and evaluation criteria. Articulating prevalent design perspectives should make overlooked design opportunities more salient, help systems designers design for scale more deliberately and understand their tradeoffs, and open up new opportunities to designers who shift their perspectives.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78875806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present LiveDataLab, a novel general cloud-based platform that facilitates data science education at scale by enabling instructors to offer hands-on data science assignments using large real-world datasets. Using real course assignments as examples, our demonstration will walk attendees through the process of an instructor deploying an assignment, students working on and submitting assignments, and leaderboard-based competition and automated grading to demonstrate the major functions and benefits of LiveDataLab.
{"title":"LiveDataLab","authors":"Aaron Green, ChengXiang Zhai","doi":"10.1145/3330430.3333665","DOIUrl":"https://doi.org/10.1145/3330430.3333665","url":null,"abstract":"We present LiveDataLab, a novel general cloud-based platform that facilitates data science education at scale by enabling instructors to offer hands-on data science assignments using large real-world datasets. Using real course assignments as examples, our demonstration will walk attendees through the process of an instructor deploying an assignment, students working on and submitting assignments, and leaderboard-based competition and automated grading to demonstrate the major functions and benefits of LiveDataLab.","PeriodicalId":20693,"journal":{"name":"Proceedings of the Sixth (2019) ACM Conference on Learning @ Scale","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77320092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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