About Me

I worked on my Ph.D from 2016 to 2022 at the University of Koblenz-Landau, Germany. In 2022, I moved to the Vrije Universiteit Brussel (VUB) working there as a postdoc. My special interests include software language engineering, empirical software engineering, statistic modelling, probabilistic programming, functional programming, machine learning, neural networks, natural language processing, big-data processing, mining software repositories, testing, and model-driven software engineering techniques.

Teaching

The material for the current course Capita Selecta of Software Engineering (2023/2024) is hosted on GitHub.

Publications

• Johannes Härtel and Ralf Lämmel: Operationalizing Validity of Empirical Software Engineering Studies Empirical Software Engineering (vol 28) (2023)
• Ward Muylaert and Johannes Härtel and Coen De Roover: Symbolic Execution to Detect Semantic Merge Conflicts SCAM (2023)
• Johannes Härtel and Ralf Lämmel: Operationalizing Threats to MSR Studies by Simulation-Based Testing MSR (2022)
• Marcel Heinz and Johannes Härtel and Ralf Lämmel: Reproducible Construction of Interconnected Technology Models for EMF Code Generation Journal of Object Technology (vol 19) (2020)
• Juri Di Rocco and Davide Di Ruscio and Johannes Härtel and Ludovico Iovino and Ralf Lämmel and Alfonso Pierantonio: Understanding MDE projects: megamodels to the rescue for architecture recovery Software and Systems Modeling (vol 19) (2020)
• Johannes Härtel and Ralf Lämmel: Incremental Map-Reduce on Repository History SANER (2020)
• Philipp Seifer and Johannes Härtel and Martin Leinberger and Ralf Lämmel and Steffen Staab: Empirical study on the usage of graph query languages in open source Java projects SLE (2019)
• Johannes Härtel and Marcel Heinz and Ralf Lämmel: EMF Patterns of Usage on GitHub ECMFA (2018)
• Juri Di Rocco and Davide Di Ruscio and Johannes Härtel and Ludovico Iovino and Ralf Lämmel and Alfonso Pierantonio: Systematic Recovery of MDE Technology Usage ICMT (2018)
• Johannes Härtel and Hakan Aksu and Ralf Lämmel: Classification of APIs by hierarchical clustering ICPC (2018)
• Johannes Härtel and Lukas Härtel and Ralf Lämmel and Andrei Varanovich and Marcel Heinz: Interconnected Linguistic Architecture Art Sci. Eng. Program. (vol 1) (2017)
• Simon Schauss and Ralf Lämmel and Johannes Härtel and Marcel Heinz and Kevin Klein and Lukas Härtel and Thorsten Berger: A chrestomathy of DSL implementations SLE (2017)
• Johannes Härtel and Lukas Härtel and Ralf Lämmel: Test-Data Generation for Xtext (Tool Paper) SLE (2014)
• Harbusch, Karin and Cameran, Christel-Joy and Härtel, Johannes: Under\-specification-based grammatical feedback generation tailored to the learner's current acquisition level in an e-learning system for German as second language Proc.\ of EUROCALL (2014)
• Karin Harbusch and Johannes Härtel and Christel-Joy Cameran: COMPASS III: teaching L2 grammar graphically on a tablet computer Proc.\ of SLaTE (2013) - Workshop speech and language technology in education (2013)
• Harbusch, Karin and Cameran, Christel-Joy and Härtel, Johannes: Personalized grammar teaching on a tablet in inclusion classrooms Proc.\ of International Conference on Using New Technologies for Inclusive Learning (2013)