ScienceR blog

Date Title Reading Time
Feb 6, 2024 Rational and humane drug policy 2 min
Feb 4, 2024 You (or your university) don’t own your data 7 min
Oct 6, 2023 Preregistering Systematic Reviews 5 min
Aug 26, 2023 A-bit-of-X-odus 1 min
Aug 24, 2023 Using Git in Shiny Apps 3 min
Aug 1, 2023 Health Psychology in 2023: Transforming Paradigms 3 min
Jul 27, 2023 The Intervention Mapping Summer Course 2023 5 min
Jul 22, 2023 Alcohol of drugs: wat is slechter voor je? 5 min
Jul 10, 2023 Intervention Mapping in a thread 2 min
Jan 11, 2023 Converting a Quarto blog post to a Mastodon thread and posting it 3 min
Jan 3, 2023 Using the Reproducible Open Coding Kit & Epistemic Network Analysis to model qualitative data 8 min
Dec 14, 2022 Acyclic Behavior Change Diagrams: A Tool to Report and Analyze Interventions 7 min
Dec 2, 2022 Knowing what we’re talking about: a Mastodon thread 4 min
Nov 13, 2019 Collaborating on reproducible manuscripts for dummies: an introduction using git, R Markdown and Zotero 5 min
Oct 14, 2019 Is er sprake van ‘normalisering’ van drugsgebruik? 70 min
Sep 14, 2019 A poor person’s guide to Open Sciencing GDPR compliant data management 5 min
Apr 3, 2019 A reproducible research workflow: GitLab, R Markdown, and Open Science Framework 7 min
Mar 9, 2019 The hare and the turtle: why agile approaches are often not feasible in applied psychology 8 min
Feb 8, 2019 Een voorbeeld van de ABCD in de dagelijkse praktijk van interventie-ontwikkeling 13 min
Jan 29, 2019 Acute risico’s van XTC-gebruik 42 min
Nov 18, 2018 Hoe voorkomen we een nieuwe WODC affaire? 10 min
Oct 24, 2018 Kritische analyse van de reacties van het Trimbos Instituut en Novadic Kentron op de legaliseringsdiscussie 21 min
Oct 23, 2018 Waarom legalisering van XTC gezondheidsschade en slachtoffers voorkomt 18 min
Sep 11, 2018 De wereld gebruikt veel minder XTC pillen dan geschat 8 min
Sep 11, 2018 How much XTC does the world use every year? 8 min
Sep 1, 2018 Much less ecstasy used (and produced?) in the Netherlands than recent report suggests 12 min
Aug 28, 2018 Nederland gebruikt veel minder XTC pillen dan geschat 12 min
Jun 8, 2018 Constructs, operationalisations, mediators, and why behavior change techniques cannot change behavior 25 min
Oct 19, 2017 Een toetsingskader voor Harm Reduction interventies: beschouwing vanuit de theorie en praktijk van effectieve gedragsverandering 14 min
Oct 2, 2017 Why estimations of determinant relevance should not be based on regression analysis 5 min
Aug 8, 2017 Appropriate humility: choosing sides in the alpha wars based on psychology rather than methodology and statistics 10 min
Aug 4, 2017 When wishful thinking kills: the tragic consequences of misplaced faith in introspection 4 min
Jun 22, 2017 How to select junior (or other) researchers, and why not to use Impact Factors 18 min
May 3, 2017 Theories versus logic models 2 min
Apr 6, 2017 Why one randomization does not a successful experiment make 14 min
Feb 1, 2017 On the obsession with being normal 5 min
Dec 28, 2016 Fear is a bad counsellor 8 min
Mar 25, 2016 Why one-sided tests in psychology are practically indefensible 7 min
Jan 28, 2016 Gezondheidscommunicatie op tabaksverpakking: angst is een slechte raadgever 7 min
Sep 22, 2015 Een niet-representatieve steekproef zegt ja tegen MDMA 14 min
Aug 26, 2015 The importance of matching: a case study 11 min
Aug 6, 2015 Countering antivaccination attitudes: don’t twiddle the dials before examining the engine 13 min
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Living (in progress) books

One of the formats I use to publish contents is living1 open access books.

  • The Book of Behavior Change: this book is a practical handbook for developing behavior change interventions. It does not cover the entire intervention development process, nor provide much theoretical background, instead providing practical tools. It is based on what are basically simple (trivial, even) but inevitable mechanics based on how the human psychology and behavior change work. As such, the book can be used alongside whichever approach one uses, be it Intervention Mapping, the Behavior Change Wheel, Design Thinking, or what have you.

  • The ROCK book: The Reproducible Open Coding Kit book, or the ROCK book, describes the Reproducible Open Coding Kit, a versatile open standard for embedding codes in qualitative data (well, as long as the data are textual, e.g. interview transcripts). The ROCK book also describes the {rock} R package, to analyse sources coded with the ROCK standard, and the iROCK interface, to easily code qualitative sources with the ROCK.

  • SysRevving: The SysRevving book is an open access book about doing open and systematic systematic reviews using open source tools. That is not a typo: it really says systematic systematic reviews, reflecting how this book aims to make systematic reviews as systematic as possible. This is tied in with the aim of making them as open, transparent, and machine-readable as possible.

Brief bio

I was born in Sneek in 1981, and was raised in Grou (both in Fryslân). After high-school, I moved to Enschede to study computer science in 1999. There, I found out, first, that this was not about coding as much as about mathematics, and second, that mathematics was not my strong suit. I stopped after six months and moved to Maastricht, where I started studying psychology at Maastricht University. I continued on a PhD. with Gerjo Kok, studying ecstasy use-related harm reduction strategies, and then a post-doc on threatening communication as a behavior change method.

In 2011, I moved to the Open University of the Netherlands as an assistant professor at the Methods & Statistics department, where I became associate professor in 2021. Over time, my research interests have broadened from a focus on behavior change science and nightlife-related risk behaviors to also include methodology (of quantitative approaches as well as qualitative approaches and evidence synthesis), measurement, and validity.

My curriculum vitae contains more details about the kind of stuff I do. I only update it when I apply for a job; the last time was in September 2022. You can download my CV here.


  1. Living books are books that can be updated ‘live’, instead of requiring discontinuous release through formal editions. Each of these books will, however, get assigned formal editions every time substantial revisions have taken place compared to the previous version. The first formal edition will mark the first version of the book that is considered finished, and from that point onwards, the DOI of each book will be updated so that each new edition will have a unique DOI.↩︎