Without any doubt, creating links and navigational trails is fundamental to hypertext. The Web is the widest spread representative among all systems in the history of hypertext, although its underlying core concept is kept simple. This is why the Web's widely used link functionality is naive, supporting only embedded, unary and unidirectional links. A strength of the Web is its extensibility, giving us the opportunity to augment the current functionality of links. We showcase a browser plugin, which enables users to create and share complex links over the existing Web. Furthermore, we discuss the CB-OHS Mother, its link model and how this relates to existing work. The implementation adopts latest standardization efforts and is an update to older attempts of enabling external link services for the Web.

This blue sky paper presents the Thoughts Reflection Machine (TRM) which combines hypertext technologies and intelligent components. Using hypertext, the TRM provides means to its users to express or communicate their thoughts and ideas. Furthermore, the machine suggests relevant information that trigger users' creative thinking. The TRM is an approach towards a tight cooperation between human and machine supporting both in their specific tasks in which they are most excellent in: creative problem solving respective computation of huge data sets.

User behavior and the resulting behavioral data forms the basis of personalized feeds, recommendations and advertisements in social networks such as Facebook. These platforms are now required to provide users with their personal data. However, these dumps with chronological data in different files do not provide users insight in overarching themes and connections in their online behavior. In this paper, we discuss the development and preliminary evaluation of an exploratory interface for visual data exploration. First insights include that the less obvious, more associative and obscure connections are more interesting and relevant to the user than very close semantic or temporal connections.

Social networks such as Facebook are required to provide users with their personal data. However, these dumps do not provide users insight in overarching themes in their online behavior. In this poster, we discuss the development of Mother, a spatial hypertext system for visual data exploration. First insights include that the less obvious connections are more interesting and relevant to the user than very close semantic or temporal connections.

Social networks use several user interaction techniques for enabling and soliciting user responses, such as posts, likes and comments. Some of these triggers may lead to posts or comments that a user may regret at a later stage. In this article, we investigate how users may be supported in reflecting upon their past activities, making use of an exploratory spatial hypertext tool. We discuss how we transform raw Facebook data dumps into a graph-based structure and reflect upon design decisions. First results provide insights in users motivations for using such a tool and confirm that the approach helps them in discovering past activities that they perceive as outdated or even embarrassing.

It is our great pleasure to welcome you to the 30th Anniversary ACM Conference on Hypertext and Social Media at Hof University, Germany, on September 17-20, 2019. The ACM Hypertext conference is a premium venue for high quality peer-reviewed research on hypertext theory, systems and applications. It is concerned with all aspects of modern hypertext research including social media, semantic web, dynamic and computed hypertext and hypermedia as well as narrative systems and applications. The theme of Hypertext 2019 is "HYPERTEXT - TEAR DOWN THE WALL". This motto of the 30th ACM Hypertext conference goes hand in hand with the 30th anniversary of the fall of the Berlin Wall. Inspired by the historical events in Germany, Hypertext 2019 aims at reunifying different hypertext research directions and communities. Therefore, apart from the regular research tracks, Hypertext 2019 will feature a research track on 30 Years of Hypertext as well as an exhibition/creative track. 2019 will also be the 30th anniversary of the WWW. It is a perfect time to join in, reflect our common roots, and discuss how we can jointly address our current and future challenges. The conference will take place at the Institute of Information Systems (iisys) at Hof University, Germany. Hof lies midway between Frankfurt and Prague, Munich and Berlin and is very close to the former German-German border, in particular to the village of Modlareuth, called "little Berlin", which used to be divided by a wall. After exactly 20 years, Hypertext 2019 will take place in Germany again for the 2nd time. Hypertext 2019 is co-locating with the ACM Document Engineering Conference (DocEng'19) organized in Berlin, Germany, between September 23-16.

Welcome to the Human Factors in Hypertext 2019 workshop (HUMAN'19) in Hof, Germany, the second workshop of a young series of workshops for the ACM Conference on Hypertext and Social Media. It has a strong focus on hypertext users and thus complements the machine analytics research that we experienced in previous conferences. The user-centric view on hypertext not only includes user interfaces and interaction, but also discussions about hypertext application domains. Furthermore, the workshop raises the question of how original hypertext ideas (e.g., Doug Engelbart's "augmenting human intellect" or Frank Halasz' "hypertext as a medium for thinking and communication") can improve today's hypertext systems. Historically, hypertext research strongly connects to human factors. Hypertext pioneers, such as Doug Engelbart or Ted Nelson, focused on the usage of and interaction with hypertext. This workshop combines original hypertext research ideas with recent hypertext research trends. In addition, it consolidates different hypertext research areas from the viewpoint of human factors. Thus, HUMAN'19 fosters cross-cutting discussions and the development of new ideas.

Historically, there has been a tendency to consider hypertext as a type of system, perhaps characterized by provision of links or other structure to users. In this paper, we consider hypertext as a method of inquiry, a way of viewing arbitrary systems. In this view, what are traditionally called "navigational hypertext systems" might be considered as information retrieval systems, "spatial hypertext systems" as brainstorming systems, etc., while their "hypertext" nature results from the way in which such systems are conceived, developed, and/or presented. The benefit of such a shift is the ability to apply this hypertextual method of inquiry to systems not normally considered part of the hypertext community. In this paper, we specifically apply this view to artificial intelligence, and examine how this application can be productive.

The task of organizing and retrieving knowledge is often elaborative and involves different types of media including digital or analog. In this paper we describe a system that is based on related research in the fields of spatial hypertext, information retrieval, and visualization. It utilizes a 2D space on which users can add, remove, or manipulate information entities (so-called user nodes) visually. A spatial parser recognizes the evolving structure and queries a knowledge base for helpful other information entities (so-called suggestions nodes). Similar to user nodes, those suggestions are presented as visual objects in the space. We propose a physics model to simulate their behavior. Their characteristics encode the relevance of suggestions to user nodes and to each other. This enables human recipients to interpret the given visual clues and, thus, identify information of interest. The way users organize nodes spatially influences the parsed spatial structures, i.e., the placement of suggestion nodes. This allows the creation of complex queries without any prior knowledge, yet the users do not have to be aware of that, because they can express their thoughts implicitly by manipulating their nodes. We discuss the strengths of a physics based simulation to encode context visually and point to open issues and potential solutions. On the basis of an implemented demonstrator we show the benefits compared to similar and related applications in the field of information visualization, especially when it comes to tasks where a high portion of creativity is involved and the information space is not well known.

In this paper, we describe our project DemoMedia, a software demonstrator that combines hypertext and recommender functionality in the context of video acquisition or use. DemoMedia fills the gap that exists in today's video platforms which include recommender functionalities, but only trivial support for users to structure information. Thus, users are forced to write down notes from or about videos (needed for various reasons) on additional media, such as paper. This opens a media gap between video platform and note-taking or communication to others. DemoMedia becomes a note taking and communication tool for the user, as it offers a knowledge space on which users can freely arrange and associate information. Furthermore, its intelligent parsers compute relations that are implicitly expressed and queries knowledge bases for relevant information or related videos. Those get positioned on the space in a semantically meaningful way. DemoMedia and the underlying component-based open hypermedia system Mother combine both the machine's capability of extracting knowledge from huge amounts of data and the human capability of sensemaking, intuition, and creativity.

Welcome to the Human Factors in Hypertext 2018 workshop (HUMAN'18) in Baltimore, Maryland, USA, the first workshop of a new series of workshops for the ACM Conference on Hypertext and Social Media. It has a strong focus on hypertext users and thus complements the machine analytics research that we experienced in previous conferences. The user-centric view on hypertext not only includes user interfaces and interaction, but also discussions about hypertext application domains. Furthermore, the workshop raises the question of how original hypertext ideas (e.g., Doug Engelbart's "augmenting human intellect" or Frank Halasz' "hypertext as a medium for thinking and communication") can improve today's hypertext systems. Historically, hypertext research is strongly connected to human factors. Hypertext pioneers, such as Doug Engelbart or Ted Nelson, focused on the usage of and interaction with hypertext. This workshop combines original hypertext research ideas with recent hypertext research trends. In addition, it consolidates different hypertext research areas from the viewpoint of human factors. Thus, HUMAN'18 fosters cross-cutting discussions and the development of new ideas.

The idea to associate information with so-called links was developed by hypertext pioneers in the 1960s. In the 1990s the Dexter Hypertext Reference Model was developed with the goal to provide a general model for node-link hypertext systems. In the 1990s and 2000s there were important steps made for hypertext infrastructures, which led to component-based open hypermedia systems (CB-OHS). In this paper we provide a detailed description of node-link structures. We argue that Dexter does not match the need of CB-OHS, as it supports a mix of multiple structure domains. Based on the implementation of link support in our system Mother we demonstrate how Dexter needs to be tailored accordingly. We further describe Mother's ability of node-link structures to interoperate with other available structure services and vice versa.

Software applications become more and more dominant in our daily life and work. However, it is very difficult to provide sophisticated tools for all arising use cases. End-User Development (EUD) is a term that describes the development of applications by end users rather than professional developers. This enables them creating highly specialized solutions. End users are laypersons when it comes to building software, therefore they need appropriate tools for managing the whole development process. This includes designing, implementing and deploying applications. While there are already various tools available, we focus on a recommendation feature for graphical EUD tools, utilizing their spatial hypertext capabilities. In this paper we provide an overview of some common issues such tools are often struggling with. We explain how visually analyzing the workspace, parsing an implicit spatial hypertext and eventually presenting recommendations may tackle them. We further describe the project HEIMDALL in detail, especially the way of generating recommendations for software modules with the aim to raise users' awareness. Furthermore, we discuss the use of such a system that reaches a similar understanding of relationships between software modules as users have. Finally, we point to open issues that still need to be addressed to improve results and their presentation.

Specialized systems aiming at offering hypertext functionality in users' computing have been discussed since the early days of hypertext. However, with the claim to also support other structure domains than node-link structures, hypertext systems had to overcome some challenges. Researchers came up with component-based approaches and low level structure services.
Due to the raising omnipresence of the Web, research on traditional hypertext systems has been fading out over the past decade. This paper focuses again on hypertext infrastructures and goes beyond ongoing Web discussions. Based on lessons learned from well thought through previous work, we present a novel design for multi-structure supporting, general purpose hypertext systems that can be used in a series of application domains. The system provides intelligence analysis which is needed for sophisticated user support. We argue that this lets us use the hypertext system also as a visual analytics tool. Furthermore, for demonstration purposes we describe the use of the system in combination with a Web-based software engineering platform, which is part of the ongoing project ODIN.

Spatial hypertext represents associations between chunks of information by spatial or visual attributes (such as proximity, color, shape, etc.). This supports expressing information structures implicitly and in an intuitive way. However, automatic recognition of such informal, implicitly encoded structures by a machine (a so-called spatial parser) is still a challenge. Conventional parsers are conceptually restricted by their underlying source of information. Due to this limitation there are various possible structures that cannot be recognized properly, as the machine has no means to detect them. This inevitably limits both the quality of parser output and hence parser performance. In this paper we show that considering temporal aspects in spatial parser design will lead to significant increase in parsing accuracy, detection of richer structures and thus higher parser performance. We call machines that consider such spatial and temporal information spatio-temporal parsers.

For the purpose of providing evidence, parsers for recognizing spatial, visual, and temporal object relations have been implemented and tested in a series of user surveys. One aim was to find out how "close" the machine interpretetation of structures get to human interpretation. It turned out that in none of the test cases pure spatial or visual parser could outperform the spatio-temporal parser. Instead, the spatio-temporal parser was able to compensate limitations of conventional parsers. Furthermore, we have statistically tested parsing accuracy. The results indicate a non-trivial effect that is recognizable by humans. This shows that spatio-temporal parsers produce output that is significantly closer to what knowledge workers intend to express compared to traditional spatial parsers.

As multitouch phones and tablets become more popular, multitouch technologies receive increasing attention. The underlying interaction paradigm of such devices is the space on which objects are manipulated by the user's fingertips. It is natural that hypertext narratives find their way from primarily mouse-driven interaction to spatial structures and visually rich presentations. In this article we propose three features for multitouch hypertext narrative applications: (i) Native multitouch support and direct manipulations of fictive objects; (ii) using the space as a structuring mechanism rather than a means for presentation; and (iii) supporting presentation of visually rich objects. Our prototype, TouchStory, is a novel tool specialized for authoring and reading hypertext narratives that integrates these features.