Ionica Smeets


Image by Sija van den Beukel

Professor of Science Communication - Leiden University


The publications listed below are in reverse chronological order and separated by year of publication.


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Vonk, A. N., Bos, M., Smeets, I. & van Sebille, E. (2024). A comparative study of frames and narratives identified within scientific press releases on ocean climate change and ocean plastic. JCOM 23(01), A01. doi: 10.22323/2.23010201

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To understand how scientific institutions communicate about ocean climate change and ocean plastic research, 323 press releases published between 2017 and 2022 were analyzed. A clustering method revealed 4 ocean climate change- and 5 ocean plastic frames that were analyzed qualitatively. Ocean plastic was presented as a biological and health issue, placing an emphasis on solutions and society′s obligation to implement them. Ocean climate change was framed as environmental and socio-economic problem, highlighting politics′ responsibility for mitigation. Narratives were only used to personify science and represent scientists, indicating that future press releases could include more social dimensions to engage audiences in ocean issues.


Lungu, D.A,, Røislien, J., Berg, S.H., Smeets, I., Shortt, M.T., Thune, H. & Brønnick, K.K. (2023). Assessing the Effect of Nonvisual Information Factors in Pandemic-Related Video Communication: Randomized Controlled Between-Subjects Experiment. J Med Internet Res 2023;25:e42528. doi: 10.2196/42528

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Background: Videos have been an important medium for providing health and risk communication to the public during the COVID-19 pandemic. Public health officials, health care professionals, and policy makers have used videos to communicate pandemic-related content to large parts of the population. Evidence regarding the outcomes of such communication, along with their determinants, is however limited.
Objective: The aim of this study was to test the impact of nonvisual information factors of video communication on 4 outcomes: trust, comprehension, intentions, and behavior.
Methods: Twelve short health communication videos related to pandemics were produced and shown to a large sample of participants, applying a randomized controlled between-subjects design. Three factors were included in the creation of the videos: the topic (exponential growth, handwashing, and burden of pandemics on the health care system), the source (expert and nonexpert), and a call to action (present or absent). Participants were randomly assigned to 1 video intervention, and 1194 valid replies were collected. The data were analyzed using factorial ANOVA.
Results: The 3 pandemic-related topics did not affect trust, comprehension, intentions, or behavior. Trust was positively influenced by an expert source (2.5%), whereas a nonexpert source instead had a positive effect on the proxy for behavior (5.7%) compared with the expert source. The inclusion of a call to action had a positive effect on both trust (4.1%) and comprehension (15%).
Conclusions: Trust and comprehension in pandemic-related video communication can be enhanced by using expert sources and by including a call to action, irrespective of the topic being communicated. Intentions and behavior appear to be affected to a small extent by the 3 factors tested in this study.

Meinsma, A.L, Kristensen, S.W., Reijnierse, W.G., Smeets, I. & Cramer, J. (2023). Is everything quantum 'spooky and weird'? An exploration of popular communication about quantum science and technology in TEDx talks. Quantum Science and Technology 8 (3), A07. doi: 10.1088/2058-9565/acc968

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Previous studies have identified four potential issues related to the popularisation of quantum science and technology. These include framing quantum science and technology as spooky and enigmatic, a lack of explaining underlying quantum concepts of quantum 2.0 technology, framing quantum technology narrowly in terms of public good and having a strong focus on quantum computing. Before assessing the effect of these potential issues on public perceptions, it is important to first determine whether these issues are actually present in popular communication. To this end, we conducted a content analysis in which we investigated how quantum science and technology are framed in a corpus of 501 TEDx talks. We also examined to what extent quantum experts, such as quantum scientists and leaders at organisations in quantum science and technology, communicate about quantum science and technology differently from non-experts, such as scientists from other disciplines and artists. Results showed that: (1) about a quarter of the talks framed quantum science and technology as spooky/enigmatic; (2) about half of the talks explained at least one underlying quantum concept (superposition, entanglement or contextuality) of quantum 2.0 technology; (3) quantum technology is narrowly framed in terms of public good as we found six times more talks mentioning benefits than risks; and (4) the main focus is on quantum computing at the expense of other quantum technologies. In addition, experts and non-experts differ on three out of four issues (only the fourth issue is similar for both). Our findings thus show that these potential issues related to the popularisation of quantum science and technology are present but not predominant in TEDx talks. Further research should explore their effect on public perceptions of quantum science and technology.

Verkade, A. & Smeets, I. (2023). National Centre of Expertise on Science & Society — The Netherlands — Action plan (summary). doi: 10.5281/zenodo.7808844

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The National Centre of Expertise on Science & Society of the Netherlands aims to foster the connection between science and society. Due to several structural changes, the risk of science and society drifting apart has increased. Therefore, science communication needs to improve. Better science communication means a wider reach in society, engaging more in dialogue and interaction in addition to one-way communication, more focus on scientific methods and processes in addition to scientific results and activities have to become more effective and impactful. In the future, this will result in Dutch citizens having a better understanding of processes and practices in science, as well as knowledge of the role of science in our history and culture. Citizens will more often be involved in science on equal terms. The centre must act as a catalyst to strengthen the current and future field of science and society by implementing these improvements. The summary of the action plan illustrates what methods will be applied to achieve the centre′s mission.

Verkade, A. & Smeets, I. (2023). Nationaal Expertisecentrum Wetenschap & Samenleving — Plan van aanpak. doi: 10.5281/zenodo.7763918

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In dit plan van aanpak wordt het advies gepresenteerd voor een Nationaal Expertisecentrum Wetenschap & Samenleving dat het beste past in het huidige Nederland. Het Nationaal Expertisecentrum Wetenschap & Samenleving (NEWS) heeft als missie de verbinding tussen wetenschap en samenleving te bevorderen door betere wetenschapscommunicatie. Door een aantal structurele uitdagingen groeit het risico dat de samenleving en wetenschap van elkaar verwijderd raken en dat het wederzijds vertrouwen afneemt. Om dit te voorkomen moet de wetenschapscommunicatie verbeteren. Betere wetenschapscommunicatie betekent een breder bereik in de samenleving, meer interactie en gelijkwaardige dialoog naast het zenden van informatie, meer aandacht voor methode en proces van wetenschap naast resultaten en meer doelmatigheid en impact van activiteiten. Dit zal er in de toekomst voor zorgen dat meer Nederlanders begrip hebben van proces en methode van wetenschap, net als dat zij kennis zullen hebben van de rol van wetenschap in onze geschiedenis en cultuur. Burgers zullen vaker op gelijkwaardige manier betrokken zijn bij onderzoek. Het centrum moet als katalysator het bestaande en toekomstige veld van wetenschap en samenleving versterken.

Smeets, I. (2023). Why we aren′t always convinced by facts. Dies Lecture on the 448th Dies Natalis of Leiden University.

[English PDF] [Dutch PDF]

Bossema, F., Zwetsloot, C. & Smeets, I. (2023). Math in the City: Designing a Math Trail for High School Students. Handbook of Mathematical Science Communication, 53-72. doi: 10.1142/9789811253072_0005

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This chapter describes the development of a math trail for high school students. In 2016, we developed this trail through Leiden (The Netherlands) during a student project for the Science Communication and Society specialization, a track for master students at the Faculty of Science at Leiden University. Our aim was to provide a guided trail through the city that links everyday sights to mathematical concepts within the curriculum of high school students between 13 and 15 years old. The entire project was carried out in 3 weeks. We did background research, consisting of literature reviews, target audience surveys with school children, and focus groups with teachers. Based on the conclusions from this background research, we developed questions that suited both the goal to make the math trail a fun experience that makes math less abstract and the goal to include questions from across the curriculum. In this chapter, we would like to share our insights from the background research and our experiences in developing a math trail. We moreover aim to provide those who are interested in designing a math trail in their city with a practical step-by-step plan and checklist.


Shortt, M.T., Berg, S.H., Wiig, S., Lungu, D.A., Smeets, I., Thune, H. & Røislien, J. (2022). Exploring Health Experts′ and Creative Communicators′ Focus in Pandemic Video Communication: A Qualitative Study. Front. Commun. 7:886768. doi: 10.3389/fcomm.2022.886768

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Pandemic video communication aimed at the general public often lacks creativity and fails to reach large audiences. Yet, the scientific content should not be compromised by attempts to improve the creativity or reach. This study explores the processes utilised by various health experts and professional communicators when creating communication, to identify similarities and differences, and how pandemic video communication thus can be improved through an interdisciplinary approach. We interviewed 12 individuals from 6 different professional domains: health, public health, film/science communication, video journalism, advertising, and social media/YouTube. Semi-structured individual interviews were conducted using the same interview guide. The interview data were subjected to thematic analysis with both deductive and inductive coding, and the results were visualised in a bubble chart. Our study has highlighted both similarities and differences between health professionals and creative communicators relating to their creative processes and their approaches to pandemic video communication. We found that participants from health domains assigned great importance to and efforts on the content, but were unsure or lacked experience in how content is translated through form and creativity. Creative communicators, on the other hand, emphasise and specialise in form, yet depend on health professionals, experts, and scientists to provide and validate content. The key to improving pandemic-related video communication appears to lie in striking the right balance between high-quality and evidence-based content and creativity. This study found that both health professionals and creative communicators play crucial roles in reaching a solid end result, and we suggest a fusion model approach to interdisciplinary collaboration.

Wijnker, W., Smeets, I., Burger, P., & Willems, S. (2022). Debunking strategies for misleading bar charts. JCOM 21 (07), A07. 10.22323/2.21070207

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Graphs are useful to communicate concisely about complex issues. Although they facilitate intuitive reading of data, trends, and predictions, hasty readers may still come to the wrong conclusions, especially if graphs are misleading due to violated design conventions. To provide evidence about how to prevent misinformation from spreading by misleading graphs, this two-survey experimental study investigates the effectiveness of four correction methods as debunking strategies to correct bar charts with manipulated vertical axes. All four methods showed positive effects. The most effective one is aimed at correcting the initial image by presenting an accurate alternative graph. A reduced effect remained visible after one week.

Bruijnzeel, A., Cramer, J., De Bruyckere, P., Smeets, I., & Yazilitas, D. (2022). How Diverse Is Diversity? An Exploration of References to Diversity in the Recent Literature in STEM Higher Education. European Journal of STEM Education. 2022;7(1), 12. doi: 10.20897/ejsteme/12667

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Since STEM knowledge and skills are increasingly being sought after in our information and technology driven economies, it is pivotal that ideas and human resources that foster these economies also reflect the STEM population. Although it is evident from earlier research that specific demographics are clearly underrepresented, little is known about who constitutes as ′diverse′, which makes it challenging to develop and assess effective policies aimed at increasing diversity in STEM. Through content analysis, we explore in recent STEM education literature, which groups of students and faculty are referenced in relation to diversity, i.e., groups that are underrepresented. The results reveal 180 uniquely defined references to underrepresented groups in STEM. Our main results show that across articles, the majority of the references to diversity are related to gender (69%), and a considerable portion of references (12%) can be classified under ′other unspecified minorities′. Consequently, the analyzed articles portray a narrow understanding of diversity, and a variety of groups remain unspecified when it comes to background characteristics. To change this, clear definitions of the target groups are necessary and more consensus among the research community about the justifications to include or exclude these groups is needed.

Aarts, N., Smeets, I., & Vanwesenbeeck, I. (2022). Wetenschapscommunicatie in de spotlights. Tijdschrift voor Communicatiewetenschap 50(3): 141-146. doi: 10.5117/TCW2022.3.001.AART

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Written as an introduction to a special edition on science communication.

Ochu, E., Russo, P., & Smeets, I. (2022). “The future is now” — a European perspective on the future of science communication. JCOM 21(05), R03. doi: 10.22323/2.21050603

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The Future of SciComm 2.0 conference was a one-day event in Brussels on April 26th 2022. Focusing on the future of European science communication, sixty participants from twelve countries with different expertise discussed the current challenges and possible solutions for the field. Key themes centred around disinformation, communicating global challenges, evidence-based practices and institutional structures woven through the plenary opening, afternoon workshops and the closing public panel discussion. The conclusion is a need for an European science communication ecosystem that is transdisciplinary, connected and cooperative in practice, weaving between policy, research and industry. Finally, citizen science and open science could be included as scholarly praxes to facilitate societal interconnectivity.

Hooykaas, M.J.D., Schilthuizen, M., Albers, C.J., & Smeets, I. (2022). Species identification skills predict in-depth knowledge about species. PLoS ONE 17(4): e0266972. doi: 10.1371/journal.pone.0266972

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To raise biodiversity awareness effectively, communicators should be aware of knowledge levels in their audiences. Species identification skills have been used in the past as a measure of what people know about species, yet it is not known whether they serve as good indicators. To study the link between species identification and in-depth species knowledge, we presented an animal knowledge test to an online audience of over 7,000 Dutch adults, and used correlation and regression analyses to determine the extent to which species identification predicts in-depth knowledge about species′ origin, habitat, diet, and behavior. We found that in-depth knowledge was higher in those who correctly identified species as compared with those who did not correctly identify species, for all four types of in-depth knowledge. Moreover, as compared to alternative variables (work, age, gender, and educational level), species identification was by far the best predictor for in-depth knowledge about species. However, species identification levels were generally higher than levels of in-depth knowledge, and knowledge gaps and misconceptions were uncovered. The results confirm the value of species identification tests, but also highlight limitations and challenges that should be taken into account when establishing knowledge levels and communicating biodiversity.

Driessen, J.E.P., Vos, D.A.C., Smeets, I., & Albers, C.J. (2022). Misleading graphs in context: Less misleading than expected. PLoS ONE 17(6): e0265823. doi: 10.1371/journal.pone.0265823

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Misleading graphs are a source of misinformation that worry many experts. Especially people with a low graph literacy are thought to be persuaded by graphs that misrepresent the underlying data. But we know little about how people interpret misleading graphs and how these graphs influence their opinions. In this study we focus on the effect of truncating the y-axis for a line chart which exaggerates an upgoing trend. In a randomized controlled trial, we showed participants either a normal or a misleading chart, and we did so in two different contexts. After they had seen the graphs, we asked participants their opinion on the trend and to give an estimation of the increase. Finally we measured their graph literacy. Our results show that context is the only significant factor in opinion-forming; the misleading graph and graph literacy had no effect. None of these factors had a significant impact on estimations for the increase. These results show that people might be less susceptible to misleading graphs than we thought and that context has more impact than a misleading y-axis.

Hooykaas, M. J. D., Holierhoek, M. G., Westerveld, J. S., Schilthuizen, M., & Smeets, I. (2022). Animal biodiversity and specificity in children′s picture books. Public Understanding of Science. doi: 10.1177/09636625221089811

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While animal biodiversity is declining globally, cultural representations of animals are highly prevalent in society and play an increasing part in shaping children′s perceptions of animal diversity. We studied animal portrayals in children′s picture books in the Netherlands, and coded over 2,200 animals from 217 award-winning books. We found a strong bias toward vertebrates, mammals in particular. Mammals were featured more often than other animals, played more prominent roles in the story, and were visually and textually specified more strongly. Furthermore, exotic and domestic species outnumbered native species. Picture books currently are likely to reinforce children′s perceptions toward only a small part of animal biodiversity. While we realize that picture books have other primary aims, picture book makers could be inspired and encouraged to diversify and specify their portrayals of the natural world. This would broaden children′s perceptions of the animal kingdom and could help foster lasting connections to biodiversity.

Røislien, J., O'Hara, J.K., Smeets, I., Brønnick, K., Berg, S.H., Shortt, M.T., Lungu, D.A., Thune, H., & Wiig, S. (2022). Creating Effective, Evidence-Based Video Communication of Public Health Science (COVCOM Study): Protocol for a Sequential Mixed Methods Effect Study. JMIR Res Protoc 2022;11(3):e34275. doi: 10.2196/34275

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Background: The nonlinear nature of contagious diseases and the potential for exponential growth can be difficult to grasp for the general public. This has strong implications for public health communication, which needs to be both easily accessible and efficient. A pandemic is an extreme situation, and the accompanying strict societal measures are generally easier to accept if one understands the underlying reasoning behind them. Bringing about informed attitude change and achieving compliance to strict restrictions requires explanations of scientific concepts and terminologies that laypersons can understand.
Objective: The aim of the project is to develop effective, evidence-based modes of video communication for translating complex, but important, health messages about pandemics to both the general population and decision makers. The study uses COVID-19 as a case to learn and prepare society for handling the ongoing and future pandemics, as well as to provide evidence-based tools for the science communication toolbox.
Methods: The project applies a mixed methods design, combining qualitative methods (eg, interviews, observational studies, literature reviews) and quantitative methods (eg, randomized controlled trials [RCTs]). The project brings together researchers from a wide range of academic fields, as well as communication industry professionals.
Results: This study has received funding from the Trond Mohn Foundation through the Research Council of Norway′s ′COVID-19 Emergency Call for Proposals′ March 2020. Recruitment and data collection for the exploratory first phase of the project ran from February 2021 to March 2021. Creative communication work started in May 2021, and the production of videos for use in the RCTs in the final phase of the project started in September 2021.
Conclusions: The COVCOM project will take on several grand challenges within the field of communicating science and provide evidence-based tools to the science communication toolbox. A long-term goal of the project is to contribute to the creation of a more resilient health care system by developing communication responses tailormade for different audiences, preparing society for any future pandemic.

Visscher, M., Cucurachi, S., & Smeets, I. (2022). Portrayal of the nitrogen debate in Dutch newspapers. EcoEvoRxiv preprint, 10.32942/


How sustainability challenges are relayed to the public is paramount to tackling such issues timely. However, there is still a lot to learn about the communication system between sustainability experts and the public. We looked at how Dutch newspapers portrayed the Dutch nitrogen debate that has been going on since 2019. 160 articles from four Dutch national daily newspapers were analyzed for their usage of frames and featuring of actors. The articles reflected no differences in usage of frames, however, actor portrayal varied significantly between newspapers: environmental experts appeared more often in De Volkskrant, there seemed to be a negative relationship between the number of portrayed farmers and construction workers, andpopular newspaper De Telegraaf showed more signs of partisanship than the other newspapers.


Hooykaas, M.J.D., Aten, C., Hemelaar, E.M., Albers, C.J., Schilthuizen, M., & Smeets, I. (2021). Children′s Species Literacy as Estimated and Desired by Biodiversity Communicators: a Mismatch with the Actual Level. bioRxiv preprint, bioRxiv 2021.11.10.466733.


While biodiversity decline continues and laypeople′s knowledge about species is limited, especially in children, high-quality communication is needed to raise awareness. For this, communicators should be aware of current knowledge levels in their target groups. We compared biodiversity communicators' estimates of the average species literacy level in primary school children with the actual level. Moreover, we explored the importance that communicators placed on species literacy and the level that they desired. Estimations of children′s average knowledge level varied widely and differed from the actual level. In particular, communicators overestimated the species literacy level. Although most biodiversity communicators agreed that knowledge about species is important, their view differed as to why species literacy would be important. Moreover, communicators differed with respect to the relative importance attached to different knowledge components. Professionals may thus benefit from a detailed framework of species literacy that illustrates different aspects and values. Most importantly, our findings suggest that to bridge the gap between actual and desired knowledge levels in children effectively, biodiversity communicators first need to become more aware of current perceptions in young audiences.

Shortt, M. T., Smeets, I., Wiig, S., Berg, S. H., Lungu, D. A., Thune, H., & Røislien, J. (2021). Shortcomings in Public Health Authorities′ Videos on COVID–19: Limited Reach and a Creative Gap. Frontiers in Communication, 261. doi: 10.3389/fcomm.2021.764220

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Video communication has played a key role in relaying important and complex information on the COVID-19 pandemic to the general public. The aim of the present study is to compare Norwegian health authorities’ and WHO’s use of video communication during the COVID-19 pandemic to the most viewed COVID-19 videos on YouTube, in order to identify how videos created by health authorities measure up to contemporary video content, both creatively and in reaching video consumers. Through structured search on YouTube we found that Norwegian health authorities have published 26 videos, and the WHO 29 videos on the platform. Press briefings, live videos, news reports, and videos recreated/translated into other languages than English or Norwegian, were not included. A content analysis comparing the 55 videos by the health authorities to the 27 most viewed videos on COVID-19 on YouTube demonstrates poor reach of health authorities’ videos in terms of views and it elucidates a clear creative gap. While the videos created by various YouTube creators communicate using a wide range of creative presentation means (such as professional presenters, contextual backgrounds, advanced graphic animations, and humour), videos created by the health authorities are significantly more homogenous in style often using field experts or public figures, plain backgrounds or PowerPoint style animations. We suggest that further studies into various creative presentation means and their influence on reach, recall, and on different groups of the population, are carried out in the future to evaluate specific factors of this creative gap.

Kristensen, S. W., Cramer, J., McCollam, A., Reijnierse, W. G., & Smeets, I. (2021). The matter of complex anti-matter: the portrayal and framing of physics in Dutch newspapers. Journal of Science Communication, 20(7), A02. doi: 10.22323/2.20070202

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Physics is often perceived as difficult, but there has been little research on how physics is reported in the media. In this two-stage content analysis, we examine the portrayal of physics in five major Dutch newspapers. Results show that astronomy and astrophysics is the most prominent field. Furthermore, newspaper articles are triggered almost equally by scientific and non-scientific events. Finally, the majority of described physics concepts are framed as difficult, but journalists do provide explanations for them.

Smeets, I. (2021). Vijf grote uitdagingen in de wetenschapscommunicatie. Tijdschrift voor Communicatiewetenschap, 49(2), 185–197. doi: 10.5117/TVC2021.2.005.SMEE

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Five major challenges in science communication
This article gives an overview of five major challenges in the field of science communication – with a focus on the Dutch/Flemish situation and the role that communication scientists can play in tackling these challenges.
1. The research field is fragmented and the balance between the practical and academic aspects of science communication can be improved.
2. In policies there is a large emphasis on informing society, whilst science communication should also be a dialogue with society.
3. Connecting with society is the third mission of universities, but reward systems for scientists who do this are rudimentary and should be improved.
4. Incorrect science news is at least partly caused by universities sending out exaggerated press releases. Researchers should take responsibility for how their own universities communicate about their work.
5. Social sciences and humanities are underrepresented both in science communication activities and science communication research and should be involved more.


Evers A.W.M., Colloca L., Blease C, Gaab J., Jensen K.B., Atlas L.Y., Beedie C.J., Benedetti F., Bingel U., Büchel C., Bussemaker M., Colagiuri B., Crum A.J., Finniss D.G., Geers A.L., Howick J., Klinger R., Meeuwis S.H., Meissner K., Napadow V., Petrie K.J., Rief W., Smeets I., Wager T.D., Wanigasekera V., Vase L., Kelley J.M. & Kirsch I. (2020). What Should Clinicians Tell Patients about Placebo and Nocebo Effects? Practical Considerations Based on Expert Consensus. Psychotherapy and Psychosomatics, 90(1), 49–56. doi: 10.1159/000510738

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Clinical and laboratory studies demonstrate that placebo and nocebo effects influence various symptoms and conditions after the administration of both inert and active treatments.
There is an increasing need for up–to–date recommendations on how to inform patients about placebo and nocebo effects in clinical practice and train clinicians how to disclose this information.
Based on previous clinical recommendations concerning placebo and nocebo effects, a 3–step, invitation–only Delphi study was conducted among an interdisciplinary group of internationally recognized experts. The study consisted of open– and closed–ended survey questions followed by a final expert meeting. The surveys were subdivided into 3 parts: (1) informing patients about placebo effects, (2) informing patients about nocebo effects, and (3) training clinicians how to communicate this information to the patients.
There was consensus that communicating general information about placebo and nocebo effects to patients (e.g., explaining their role in treatment) could be beneficial, but that such information needs to be adjusted to match the specific clinical context (e.g., condition and treatment). Experts also agreed that training clinicians to communicate about placebo and nocebo effects should be a regular and integrated part of medical education that makes use of multiple formats, including face–to–face and online modalities.
The current 3–step Delphi study provides consensus–based recommendations and practical considerations for disclosures about placebo and nocebo effects in clinical practice. Future research is needed on how to optimally tailor information to specific clinical conditions and patients′ needs, and on developing standardized disclosure training modules for clinicians.

Willems, S.J.W., Albers, C.J., & Smeets, I. (2020). Variability in the interpretation of probability phrases used in Dutch news articles–a risk for miscommunication. Journal of Science Communication, 19(2), A03. doi: 10.22323/2.19020203

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Verbal probability phrases are often used in science communication to express estimated risks in words instead of numbers. In this study we look at how laypeople and statisticians interpret Dutch probability phrases that are regularly used in news articles. We found that there is a large variability in interpretations, even if the phrases are given in a neutral context. Also, statisticians do not agree on the interpretation of the phrases. We conclude that science communicators should be careful in using verbal probability expressions.

Grimmon, A. S., Cramer, J., Yazilitas, D., Smeets, I., & Bruyckere, P. D. (2020). Interest in STEM among children with a low socio–economic status: further support for the STEM–CIS–instrument through the adapted Dutch STEM–LIT measuring instrument. Cogent Education, 7(1). doi: 10.1080/2331186x.2020.1745541

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When in 2014 the STEM Career Interest Survey (STEM–CIS) was developed, the researchers could check this instrument with other target audiences. Also, the question remained if the instrument was applicable for both boys and girls. This article describes the development and validation of a Dutch language version of it, called the STEM–LIT instrument, an instrument to measure the interest of children aged between ten and 12 years in Science, Technology, Engineering and Mathematics (STEM), focusing specifically on children from families with low socio–economic status (SES). The instrument has been adapted and developed in five stages and tested among Dutch primary school pupils in groups seven and eight (ages 10–11 and 11–12). The instrument was first tested in two pilot studies, after which some amendments were made. The final version of the instrument was tested with 212 pupils, with a Cronbach′s Alpha of.91, adding supporting evidence to the reliability of the original STEM–CIS instrument and showing that the test is as reliable for both girls and boys.

Hooykaas, M. J. D., Schilthuizen, M., & Smeets, I. (2020). Expanding the Role of Biodiversity in Laypeople′s Lives: The View of Communicators. Sustainability, 12(7), 2768. doi: 10.3390/su12072768

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Biodiversity is a fundamental part of sustainable development, yet it is threatened by numerous factors associated with human population growth. The current lack of broad–based support for biodiversity conservation may be explained by the widening gap between people and nature. In order to conserve biodiversity, people should be engaged in biodiversity, yet it is not yet clear what potential is present in highly urbanized environments. We conducted semi–structured interviews with twelve biodiversity communicators in the Netherlands, a highly urbanized country, and used their perceptions and experiences to explore motivations, opportunities and challenges for expanding the role of biodiversity in people′s lives in an increasingly urban world. Overall, the interviewees perceived the current role of biodiversity in laypeople′s lives to be too limited, but they were positive about the potential to expand the role. Based on communicators′ perceptions potential lies in a combination of direct exposure to biodiversity outdoors, the media, and education. Furthermore, strategically designed communication is also expected to play an essential part in opening people′s eyes for biodiversity. The results are valuable both at national and international levels, as they can motivate and aid professionals operating in urbanized contexts at reaching out to their audiences about biodiversity.

Cheplygina, V., Hermans, F., Albers, C., Bielczyk, N., & Smeets, I. (2020). Ten simple rules for getting started on Twitter as a scientist. PLOS Computational Biology, 16(2). doi: 10.1371/journal.pcbi.1007513

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Twitter is one of the most popular social media platforms, with over 320 million active users as of February 2019. Twitter users can enjoy free content delivered by other users whom they actively decide to follow. However, unlike in other areas where Twitter is used passively (e.g., to follow influential figures and/or information agencies), in science it can be used in a much more active, collaborative way: to ask for advice, to form new bonds and scientific collaborations, to announce jobs and find employees, to find new mentors and jobs. This is particularly important in the early stages of a scientific career, during which lack of collaboration or delayed access to information can have the most impact.
For these reasons, using Twitter appropriately can be more than just a social media activity; it can be a real career incubator in which researchers can develop their professional circles, launch new research projects and get helped by the community at various stages of the projects. Twitter is a tool that facilitates decentralization in science; you are able to present yourself to the community, to develop your personal brand, to set up a dialogue with people inside and outside your research field and to create or join professional environment in your field without mediators such as your direct boss.
This article is written by a group of researchers who have a strong feeling that they have personally benefited from using Twitter, both research–wise and network–wise. We (@DrVeronikaCH, @Felienne, @CaAl, @nbielczyk_neuro, @ionicasmeets) share our personal experience and advice in the form of ten simple rules, and we hope that this material will help a number of researchers who are planning to start their journey on Twitter to take their first steps and advance their careers using Twitter.


Hariman, N., de Vries, M., & Smeets, I. (2019). Topic Modeling for Exploring Cancer–Related Coverage in Journalistic Texts. In Atzmueller M., Duivesteijn W. (Eds.) Artificial Intelligence. BNAIC 2018. Communications in Computer and Information Science, vol 1021 (pp. 43–51). Springer, Cham.


Topic modeling has been used for many applications, but has not been applied to science and health communication research yet. In this paper, using topic modeling for this novel domain is explored, by investigating the coverage of cancer in news items from the New York Times since 1970 with the Latent Dirichlet Allocation (LDA) model. Content analysis of cancer in print media has been performed before, but at a much smaller scope and with manual rather than computational analysis. We collected 45.684 articles concerning cancer via the New York Times API to build the LDA model upon.
Our results show a predominance of breast cancer in news articles as compared with other types of cancer, similar to previous studies. Additionally, our topic model shows 6 distinct topics: research on cancer, lifestyle and mortality, the healthcare system, business and insurance issues regarding cancer treatment, environmental politics and American politics on cancer–related policies.
Since topic modeling is a computational technique, the model has more difficulty with understanding the meaning of the analyzed text than (most) humans. Therefore, future research will be set up to let the public contribute to analysis of a topic model.

Hooykaas, M. J., Schilthuizen, M., Aten, C., Hemelaar, E. M., Albers, C. J., & Smeets, I. (2019). Identification skills in biodiversity professionals and laypeople: A gap in species literacy. Biological Conservation, 238, 108202.

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Biodiversity is in worldwide decline and it is becoming increasingly important to expand biodiversity awareness and achieve broad–based support for conservation. We introduce the concept of species literacy, as knowledge about species can be a good starting point for engaging people in biodiversity. However, concern has been raised about a general lack of knowledge about native species. We explored species literacy via a species identification test in the Netherlands, and we investigated potential drivers of it. The dataset included 3210 general public participants, 602 primary school children aged 9/10, and 938 biodiversity professionals.
A considerable gap in species literacy was found between professionals and laypeople. Knowledge about common, native animals was particularly low in children, who on average identified only 35% of the species correctly. Mammals received relatively high identification scores as compared to birds. Laypeople′s species literacy increased with age and educational level, and was associated with positive attitudes towards nature and animals, media exposure and having a garden.
The results indicate that a considerable part of the Dutch lay public is disconnected from native biodiversity. This points to a separation between people and nature that could hinder future efforts to preserve biodiversity. Our assessment can help bridge the gap between laypeople and professionals, as it can help set up communication and education strategies about native biodiversity that fit prior knowledge.

Bossema, F.G., Burger, P., Bratton, L., Challenger, A., Adams, R.C., Sumner, P., Schat, J., Numans, M.E., & Smeets, I. (2019). Expert quotes and exaggeration in health news: a retrospective quantitative content analysis. Wellcome Open Research 4, 56. doi: 10.12688/wellcomeopenres.15147.1

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This research is an investigation into the role of expert quotes in health news, specifically whether news articles containing a quote from an independent expert are less often exaggerated than articles without such a quote.
Retrospective quantitative content analysis of journal articles, press releases, and associated news articles was performed. The investigated sample are press releases on peer–reviewed health research and the associated research articles and news stories. Our sample consisted of 462 press releases and 668 news articles from the UK (2011) and 129 press releases and 185 news articles from The Netherlands (2015). We hand–coded all journal articles, press releases and news articles for correlational claims, using a well–tested codebook. The main outcome measures are types of sources that were quoted and exaggeration of correlational claims. We used counts, 2x2 tables and odds ratios to assess the relationship between presence of quotes and exaggeration of the causal claim.
Overall, 99.1% of the UK press releases and 84.5% of the Dutch press releases contain at least one quote. For the associated news articles these percentages are: 88.6% in the UK and 69.7% in the Netherlands. Authors of the study are most often quoted and only 7.5% of UK and 7.0% of Dutch news articles contained a new quote by an expert source, i.e. one not provided by the press release. The relative odds that an article without an external expert quote contains an exaggeration of causality is 2.6.
The number of articles containing a quote from an independent expert is low, but articles that cite an external expert do contain less exaggeration.

Venhuizen, G. J., Hut, R., Albers, C., Stoof, C. R., & Smeets, I. (2019). Flooded by jargon: How the interpretation of water–related terms differs between hydrology experts and the general audience. Hydrology and Earth System Sciences Discussions, 23(1), 393–403. doi:10.5194/hess–2018–297

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Communication about water–induced hazards (such as floods, droughts or levee breaches) is important, in order to keep their impact as low as possible. However, sometimes the boundary between specialized and non–specialized language can be vague. Therefore, a close scrutiny of the use of hydrological vocabulary by both experts and laypeople is necessary.
In this study, we compare the expert and layperson definitions of 22 common terms and pictures related to water and water hazards, to see where misunderstandings might arise both in text and pictures. Our primary objective is to analyze the degree of agreement between experts and laypeople in their definition of the used terms. In this way, we hope to contribute to improving the communication between these groups in the future. Our study was based on a survey completed by 34 experts and 119 laypeople.
Especially concerning the definition of words related to water there are some profound differences between experts and laypeople: words like “river” and “river basin” turn out to have a thoroughly different interpretation between the two groups. Concerning the pictures, there is much more agreement between the groups.

Vries, M. D., Land–Zandstra, A., & Smeets, I. (2019). Citizen Scientists′ Preferences for Communication of Scientific Output: A Literature Review. Citizen Science: Theory and Practice, 42. doi:10.5334/cstp.136

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Many citizen science developers agree that participants in citizen science projects need to receive feedback on project outputs and that they should be recognized in results and publications. However, little research has thoroughly investigated the extent to which citizen scientists find communication of scientific output to be important. Citizen science studies rarely investigate this topic as their main goal. Therefore, we conducted a review on participants′ preferences for communication of data, findings, and scientific publications in papers that focus on participant motivation but which also contain relevant evidence about communication in parts of the results. We reviewed 32 peer–reviewed papers that contained relevant evidence in quantitative analyses (e.g., Likert scale–type questions) or in qualitative analyses (e.g., interviews with participants).
From this review, we conclude that participants value accessibility of their collected data, communication of project findings, and acknowledgement in publications. Taking this into account can pay off, as sharing data and findings can enhance the motivation of participants to engage in the project, thereby sustaining their participation, imparting the feeling that they spent their time well, and increasing a project′s learning impact. Some practical and ethical issues such as privacy concerns, however, need to be taken into account. This literature review is the first to provide an overview of citizen scientists′ preferences for communication of scientific output, and is a starting point for further research that should investigate the impact of different options for data sharing and communication of findings to participants.


Smeets, I. (2018). What Do People Like about Mathematics? Adults Learning Mathematics: An International Journal, 13, 7.

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In this discussion paper we look at questions that adults have about numbers. Many of their questions are not about pure mathematics, but about personal, cultural or societal issues. We discuss how to connect mathematical topics with things people are interested in, based on theoretic knowledge from the field of science communication. We focus on using narratives to make mathematics more personal, how to use games as demonstrations and different ways to present the same mathematical problem in different societal settings.

Schat, J., Bossema, F.G., Numans, M.E., Smeets, I., & Burger, J.P. (2018). Overdreven gezondheidsnieuws. Relatie tussen overdrijving in academische persberichten en in nieuwsmedia. Nederlands Tijdschrift voor Geneeskunde, 162, 5.

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Bepalen hoe vaak pers– en nieuwsberichten overdrijvingen bevatten en onderzoeken waar in het traject tussen wetenschappelijke publicatie en nieuwsbericht deze overdrijving ontstaat.
Retrospectieve kwantitatieve inhoudsanalyse.
We analyseerden persberichten over gezondheidsonderzoek die door de Nederlandse universiteiten en universitaire medische centra in 2015 waren uitgebracht (n = 129) en de aan die persberichten gerelateerde berichten in de nieuwsmedia (n = 185).
20% van de persberichten en 29% van de nieuwsberichten bevatten overdrijving van de conclusie of causale claim. Expliciet gezondheidsadvies werd indien aanwezig overdreven in 7% van de persberichten en in 10% van de nieuwsberichten. Wanneer het persbericht een overdrijving van de conclusie of causale claim bevatte, stond in 92% van de gerelateerde nieuwsberichten dezelfde overdrijving. Als de conclusie in het persbericht niet overdreven was, was 6% van de nieuwsberichten overdreven. De relatieve kans op overdreven nieuws bij een overdreven persbericht was 16,08 (95%–BI: 7,35–35,18). Bij overdreven persberichten hoorde vaker een nieuwsbericht. De relatieve kans op een nieuwsbericht bij een overdreven persbericht tegenover een niet–overdreven persbericht was 1,45 (95%–BI: 1,02–2,04).
Overdrijving in gezondheidsnieuws gaat sterk gepaard met overdrijving in het oorspronkelijke persbericht en komt voor bij meer dan 1 op de 5 artikelen. Het monitoren en zo nodig verbeteren van de nauwkeurigheid en juistheid van academische persberichten lijken een belangrijke stap om de kwaliteit van gezondheidsnieuws te verhogen.


Smeets, I. (2017). Gelijk hebben én krijgen. Vakmedianet.

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Tijdens het voorgesprek voor deze Jan de Kroes–lezing vertelde de organisatie dat veiligheidsexperts vaak mopperen dat hun leidinggevenden niet naar hen luisteren. Terwijl zij toch echt gelijk hebben, zij weten immers precies wat de risico′s zijn. Helaas blijkt het vaak lastig om anderen te overtuigen, zelfs als de feiten aan je kant staan.


Hut, R. Land–Zandstra, A.M., Smeets, I., & Stoof, C.R. (2016). Geoscience on television: a review of science communication literature in the context of geosciences. Hydrology and Earth System Sciences, 20(6), 2507–2518. doi:10.5194/hess–20–2507–2016

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Geoscience communication is becoming increasingly important as climate change increases the occurrence of natural hazards around the world. Few geoscientists are trained in effective science communication, and awareness of the formal science communication literature is also low. This can be challenging when interacting with journalists on a powerful medium like TV. To provide geoscience communicators with background knowledge on effective science communication on television, we reviewed relevant theory in the context of geosciences and discuss six major themes: scientist motivation, target audience, narratives and storytelling, jargon and information transfer, relationship between scientists and journalists, and stereotypes of scientists on TV. We illustrate each theme with a case study of geosciences on TV and discuss relevant science communication literature. We then highlight how this literature applies to the geosciences and identify knowledge gaps related to science communication in the geosciences. As TV offers a unique opportunity to reach many viewers, we hope this review can not only positively contribute to effective geoscience communication but also to the wider geoscience debate in society.

Smeets, I. (2016). Enige beschouwingen over de waarde der wetenschapscommunicatie. The acceptance of the position of professor in the field of Science Communication at Leiden University.



Bosma, W., & Smeets, I. (2013). Finding simultaneous Diophantine approximations with prescribed quality. The Open Book Series, 1(1), 167–185. doi:10.2140/obs.2013.1.167

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We give an algorithm that finds a sequence of approximations with Dirichlet coefficients bounded by a constant only depending on the dimension. The algorithm uses LLL lattice basis reduction. We present a version of the algorithm that runs in polynomial time of the input.


Kraaikamp, C., & Smeets, I. (2011). Sharp bounds for symmetric and asymmetric diophantine approximation. Chinese Annals of Mathematics, Series B, 32(2), 303–320. doi: 10.1007/s11401–011–0629–4

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In 2004, Tong found bounds for the approximation quality of a regular continued fraction convergent to a rational number, expressed in bounds for both the previous and next approximation. The authors sharpen his results with a geometric method and give both sharp upper and lower bounds. The asymptotic frequencies that these bounds occur are also calculated.


Smeets, I. (2010). On continued fraction algorithms (Doctoral dissertation, Mathematical Institute, Faculty of Science, Leiden University).

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Is there a good continued fraction approximation between every two bad ones? What is the entropy of the natural extension for alpha–Rosen fractions? How do you find multi–dimensional continued fractions with a guaranteed quality in polynomial time? These, and many more, questions are answered in this thesis.

Kraaikamp, C., Schmidt, T. A., & Smeets, I. (2010). Natural extensions for α–Rosen continued fractions. Journal of the Mathematical Society of Japan, 62(2), 649–671. doi: 10.2969/jmsj/06220649

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We give natural extensions for the α–Rosen continued fractions of Dajani et al. for a set of small α values by appropriately adding and deleting rectangles from the region of the natural extension for the standard Rosen fractions. It follows that the underlying maps have equal entropy.


Kraaikamp, C., & Smeets, I. (2009). Approximation Results for alpha–Rosen Fractions. arXiv preprint arXiv:0912.1749.


In this article we generalize Borel′s classical approximation results for the regular continued fraction expansion to the alpha–Rosen fraction expansion, using a geometric method. We give a Haas–Series–type result about all possible good approximations for the alpha for which the Legendre constant is larger than the Hurwitz constant.

Smeets, I., Lenstra, A., Lenstra, H., Lovász, L., & van Emde Boas, P. (2009). The History of the LLL–algorithm. In The LLL Algorithm (pp. 1–17). Springer, Berlin, Heidelberg. doi: 10.1007/978–3–642–02295–1_1

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The 25th birthday of the LLL–algorithm was celebrated in Caen from 29th June to 1st July 2007. The three day conference kicked off with a historical session of four talks about the origins of the algorithm. The speakers were the three L′s and close bystander Peter van Emde Boas. These were the titles of their talks.
 – A tale of two papers – Peter van Emde Boas.
 – The early history of LLL – Hendrik Lenstra.
 – The ellipsoid method and basis reduction – László Lovász.
 – Polynomial factorization and lattices in the very early 1980s – Arjen Lenstra.
This chapter is based on those talks, conversations with these four historic characters, the notes that Peter van Emde Boas and Arjen Lenstra wrote for the preproceedings, and many artifacts from the phenomenal archive of Van Emde Boas.


Kraaikamp, C., Schmidt, T. A., & Smeets, I. (2007). Tong′s spectrum for Rosen continued fractions. Journal de théorie des nombres de Bordeaux, 19(3), 641–661. doi: 10.5802/jtnb.606

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In the 1990s, J.C. Tong gave a sharp upper bound on the minimum of k consecutive approximation constants for the nearest integer continued fractions. We generalize this to the case of approximation by Rosen continued fraction expansions. The Rosen fractions are an infinite set of continued fraction algorithms, each giving expansions of real numbers in terms of certain algebraic integers. For each, we give a best possible upper bound for the minimum in appropriate consecutive blocks of approximation coefficients. We also obtain metrical results for large blocks of “bad” approximations.