IU Docs Repositorium

IU Docs

Repositorium

Researchers from IU publish their research results in numerous formats. Through this repository, we aim to make as many publications as possible available via Open Access. Gain insights into the dynamic and diverse research being conducted at IU!

Recent Submissions

Drivers of international convergence in digital two-sided platform markets: The case of dominant business model components in online lending
(PLOS ONE, 2026-07-20) Pur, Sabine; Huesig, Stefan; Schmidhammer, Christoph
Online lending marketplaces have emerged as potentially disruptive players in the financial industry by digitally connecting borrowers and lenders. However, little is known about the emergence of dominant business model patterns in this regulated, platform-based service industry. Drawing on dominant design theory, this study examines the international convergence of business model components in online lending since 2005. Using a comparative, longitudinal case study of the market leaders Funding Circle (the UK), LendingClub (the USA), and auxmoney (Germany), we analyze the Business Model Canvas components “customer segments” and “value propositions.” Our findings reveal a convergence toward peer-to-institution models, shaped by regulatory pressures, technological advances, and institutional capital. All marketplaces now address underserved borrower segments such as SMEs, the self-employed, and founders, while excluding retail investors. This indicates the emergence of internationally dominant business model components in potentially disruptive two-sided platform markets. We synthesize these findings into a generic, process-oriented model explaining how platform convergence unfolds across national contexts. This study extends dominant design theory to business models in regulated service industries and highlights external forces as key drivers of standardization. It offers practical insights for policymakers, institutional investors, and marketplace operators navigating scalability, regulation, and financial integration.
Use of single-item scales in the evaluation of German digital health applications (DiGAs): Scoping review protocol
(PLOS, 2026-08-26) Wienert, Julian; Mohammadi, Mahin
Introduction German Digital Health Applications (DiGAs) are reimbursable, patient-facing digital interventions within the German healthcare system that must demonstrate positive healthcare effects. Outcome measurement in DiGA evaluations is influenced by both methodological considerations and feasibility requirements in real-world care settings. In practice, these evaluations may be affected by factors such as limited patient adherence, high dropout rates, and variability in real-world data quality, which can complicate outcome data collection. Single-item scales may offer a low-burden alternative to multi-item instruments; however, their use, justification, and limitations in DiGA evaluations have not been comprehensively mapped. This paper presents a scoping review protocol designed to address this gap. Methods and analysis This protocol outlines a scoping review that will follow the Joanna Briggs Institute methodology and be reported in accordance with PRISMA-ScR guidelines. The review will apply the PCC framework, focusing on DiGAs listed in the BfArM DiGA directory, the use of single-item scales, and evaluations conducted within the German healthcare system. Studies will be identified primarily through the DiGA directory and supplemented by PubMed searches to verify and complete bibliographic information. Two reviewers will independently screen and verify extracted data. Quantitative data will be summarized descriptively, while qualitative information on constructs, rationales, and methodological considerations will be analyzed thematically. Results As this is a protocol, no results are reported. The planned review will provide a descriptive overview of single-item scale use in DiGA evaluations, map the constructs assessed, and identify methodological characteristics and gaps. Conclusion This protocol outlines a transparent and reproducible approach to mapping outcome measurement practices in DiGAs. The findings of the completed review will inform researchers, developers, and policymakers and support methodological development in regulated digital health contexts. Registration The scoping review protocol is registered at the Open Science Framework under the following DOI https://doi.org/10.17605/OSF.IO/A3PM5.
Soziale Aneignung in offenen digitalen Spielräumen
(IU Internationale Hochschule, 2026-08-27) Burbach, Jörg
This article examines how social order emerges in open digital game spaces when technical systems enable and structure a wide range of actions without fully determining their specific social meaning. Using Grand Theft Auto Online (GTA Online) as a case study, it argues that communal order emerges neither from formal game rules alone nor exclusively from platform governance. Rather, it develops through processes of social appropriation. The term refers to collective practices through which players socially structure a technically and institutionally framed space of possibilities by establishing shared meanings, expectations, roles, rituals, and rules. Methodologically, the article combines a qualitative-conceptual system analysis of GTA Online with an analysis of publicly accessible platform and community documents as well as the author’s previous research. It reconstructs exemplary cases including informal communities of practice such as car meets and photography groups, more enduring group structures such as crews, and institutionalized roleplay servers. These cases are not understood as necessary stages of development, but as ideal-typical positions along a continuum of increasing social consolidation. The analysis shows that actions must first be socially perceived, attributed, interpreted, and evaluated before repeated practices can give rise to situational expectations and, ultimately, communal norms. The effects of these norms remain ambivalent: they can foster reliability, cooperation, and belonging, but can also stabilize exclusion, hierarchies, and conflict. The article’s theoretical contribution lies in refining social appropriation as an analytical category for describing the transition from technical openness to ommunal order.
Selbsthilfe wirkt! Entwicklung von Resilienz durch Selbsthilfe
(Springer Nature, 2026-08-18) Hoffmann, Julia; Schulz, Arezou
Eine schwerwiegende, chronische oder als existenziell bedrohlich erlebte Erkrankung kann psychische Belastungen, Stigmatisierung, Informationsunsicherheit und tiefgreifende Alltagsveränderungen auslösen. Vor diesem Hintergrund analysiert der Beitrag, wie die Teilnahme an gemeinschaftlichen gesundheitsbezogenen Selbsthilfegruppen auf Betroffene wirkt und inwieweit sie personale und soziale Resilienz fördern kann. Resilienztheoretische und empowermentorientierte Perspektiven werden dazu mit empirischen Befunden aus Deutschland verbunden. Im Mittelpunkt stehen Selbstwirksamkeit, Zugehörigkeit, Gesundheitskompetenz, Krankheitsbewältigung, soziale Teilhabe sowie der Zugang zu verlässlichen und verständlichen Gesundheitsinformationen im Alltag. Die Befunde sprechen dafür, dass Selbsthilfegruppen unter günstigen Bedingungen Handlungsfähigkeit stärken, Isolation vermindern und den Umgang mit Erkrankungen erleichtern. Zugleich zeigen sich Ambivalenzen: Belastende Gruppendynamiken, die Konfrontation mit den Schicksalen anderer, fehlende Passung und unzureichende Zugänge können die Teilnahme erschweren oder ihren Nutzen begrenzen. Selbsthilfe ist daher weder universell wirksam noch Ersatz professioneller Versorgung. Sie ist eine eigenständige, komplementäre Ressource, deren Wirkung von Freiwilligkeit, Gruppenkultur, organisatorischer Stabilität, individueller Belastungslage und respektvoller Kooperation mit professionellen Hilfesystemen abhängt.
Serialization Trade-Offs in Distributed Systems: A Comparative Analysis of JSON, Protocol Buffers, and FlatBuffers Under Varying Width and Nesting Depth
(IU International University of Applied Sciences, 2026-08-12) Haberlah, Johannes; Linke, Knut
Serialization is a core operation in distributed systems, yet existing studies often compare individual formats without systematically controlling structural properties of the transmitted data. This paper presents a controlled comparison of three serialization paradigms: textual encoding represented by JSON, binary schema-based encoding represented by Protocol Buffers, and zero-copy representation represented by FlatBuffers. Using a Rust-based benchmark suite, the study systematically varies record width and nesting depth across four datasets and measures serialization latency, data-access latency, throughput, and serialized message size. Quantitative measurements are complemented by CPU profiling to identify low-level performance drivers. The results show that no format dominates across all dimensions. Protocol Buffers achieves the lowest serialization latency and the smallest message sizes across all datasets, supporting its suitability for write- and bandwidth-sensitive workloads. FlatBuffers provides substantially faster data access than both Protocol Buffers and JSON due to its zero-copy design, making it advantageous for read-dominated scenarios. JSON exhibits the highest access latency and generally larger payloads, but remains relevant where human readability, flexibility, and ecosystem compatibility are prioritized. Profiling attributes these differences to format-specific mechanisms: textual conversion and key emission in JSON, varint and field-wise byte encoding in Protocol Buffers, and offset/vtable resolution in FlatBuffers. The findings demonstrate that serialization format choice is a consequential architectural decision whose optimality depends on workload structure and read/write characteristics.