During the past few decades, several interconnected research traditions have paid more and more attention to the process of educational design. Educational design research seeks solutions for complex educational problems through systematic, iterative, and continuing process of design, development, and evaluation of educational practices. This special issue presents six articles including research on educational design research methodology as well as research utilizing educational design research methods.

Guest editors
Johannes Pernaa, University of Helsinki, Finland
Veli-Matti Vesterinen, University of Turku, Finland

This LUMAT special issue is a collection of selected papers from the 24^th international conference of mathematical views that was held on August 20–22, 2018 in Helsinki, Finland. The conference was a wonderful opportunity to elaborate issues related to mathematics-related affect among colleagues interested in this area of research. Out of the 25 conference presentations, 12 were submitted as a manuscript for peer review. After the review and revisions, we ended up with eight articles that you can read in this special issue.

Guest editors: Markku S. Hannula, Eeva Haataja, Anu Laine, Päivi Portaankorva-Koivisto and Enrique Garcia Moreno-Esteva, University of Helsinki, Finland

Editor-in-Chief: Prof. Maija Aksela
Managing Editor: Dr. Johannes Pernaa
Articles: 8

This special number of LUMAT assembles eight international articles on educational experiences related to out-of-school learning. Articles highlight the relevance of out-of-school learning opportunities from two main perspectives. The first perspective considers the teachers’ views and perceptions about the facilitators and constraints of out-of-school learning, and likewise the process of changing these views among science student teachers and inservice teachers. The second perspective constitutes of studies exploring science and mathematics learning opportunities in applied out-of-school settings such as science camps, exhibitions, Olympiads and photography galleries.

Guest editors
Valeria M. Cabello, Pontificia Universidad Católica de Chile, Facultad de Educación, Chile
Vesna Ferk Savec, University of Ljubljana, Faculty of Education, Slovenia

Editor-in-Chief: Prof. Maija Aksela
Managing Editor: Dr. Johannes Pernaa
Articles: 7

Editor-in-Chief: Prof. Maija Aksela
Managing Editor: Dr. Sakari Tolppanen
Articles: 4

Editor-in-Chief: Prof. Maija Aksela
Managing Editor: Dr. Sakari Tolppanen
Articles: 3

Editor-in-Chief: Prof. Maija Aksela
Managing Editor: Dr. Sakari Tolppanen
Articles: 3