Our Publications

Cornelisz, I., & Van Klaveren, C. (2019) “Educational Equity and Teacher Discretion Effects in High Stake Exams”. Economics of Education Review. Published online July 07, 2019.


This study examines teacher discretion effects in Dutch secondary education for the period 2007-2012. Stark discontinuities are observed in the exam grade distribution for high-stakes retaking students and are located at important graduation thresholds. This phenomenon is systematically related to the level of discretion when grading the exam, with results suggesting that approximately 11% of all graduating retakers did so because of teacher discretion. This yields unequal graduation opportunities that are the result of school- and subject choice patterns, since teacher discretion is structurally and selectively exerted at the school-level with the objective to let students on the margin graduate.

Cornelisz, I., Van der Velden, R., de Wolf, I. & Van Klaveren, C. (2019) “The Consequences of Academic Dismissal for Academic Success”. Studies in Higher Education. Published online March 30, 2019.


Academic dismissal policies are increasingly implemented to promote academic success, with existing empirical evidence mostly restricted to short-run outcomes. This study examines long-term academic outcomes of academic dismissal for two cohorts (N=1707) of first-year bachelor students in Economics and Business at a Dutch university. Using administrative records, regression discontinuity design estimates suggest that academic dismissal does not relate to a difference in the propensity of graduation, nor to a change in study delay, when comparing students around the academic dismissal threshold. Not meeting this credit-threshold forces students to leave, and most decide to re-enroll in the same (43.4%) program elsewhere or at least within the academic domain (41.9%). Thus, while academic dismissal forces students to switch, its intended purpose of redirecting students to a different field of study is not observed. Implications for why academic dismissal might not deliver on the intended efficiency or effectiveness gains are discussed.

Donker, T., Cornelisz, I., Van Klaveren, C., Van Straten, A., Carlbring, P., Cuijpers, P., & Van Gelder, J.L. (2019) “Effectiveness of Self-guided App-Based Virtual Reality Cognitive Behavior Therapy for Acrophobia: A Randomized Clinical Trial.”. JAMA Psychiatry. Published online March 20, 2019. 


Importance Globally, access to evidence-based psychological treatment is limited. Innovative self-help methods using smartphone applications and low-cost virtual reality have the potential to significantly improve the accessibility and scalability of psychological treatments.

Objective To examine the effectiveness of ZeroPhobia, a fully self-guided app-based virtual reality cognitive behavior therapy (VR CBT) using low-cost (cardboard) virtual reality goggles compared with a wait-list control group and to determine its user friendliness.

Design, Setting, and Participants In a single-blind randomized clinical trial, participants were enrolled between March 24 and September 28, 2017, and randomly assigned (1:1) by an independent researcher to either VR CBT app or a wait-list control group. A total of 193 individuals aged 18 to 65 years from the Dutch general population with acrophobia symptoms and access to an Android smartphone participated. The 6 animated modules of the VR-CBT app and gamified virtual reality environments were delivered over a 3-week period in participants’ natural environment. Assessments were completed at baseline, immediately after treatment, and at 3-month follow-up. Analysis began April 6, 2018, and was intention to treat.

Intervention Self-guided app-based VR CBT.

Main Outcomes and Measures The primary outcome measure was the Acrophobia Questionnaire. The hypothesis was formulated prior to data collection.

Results In total, 193 participants (129 women [66.84%]; mean [SD] age, 41.33 [13.64] years) were randomly assigned to intervention (n = 96) or a wait-list control group (n = 97). An intent-to-treat analysis showed a significant reduction of acrophobia symptoms at posttest at 3 months for the VR-CBT app compared with the controls (b = –26.73 [95% CI, −32.12 to −21.34]; P < .001; d = 1.14 [95% CI, 0.84 to 1.44]). The number needed to treat was 1.7. Sensitivity and robustness analysis confirmed these findings. Pretreatment attrition was 22 of 96 (23%) because of smartphone incompatibility. Of the 74 participants who started using the VR-CBT app, 57 (77%) completed the intervention fully.

Conclusions and Relevance A low-cost fully self-guided app-based virtual reality cognitive behavioral therapy with rudimentary virtual reality goggles can produce large acrophobia symptom reductions. To our knowledge, this study is the first to show that virtual reality acrophobia treatment can be done at home without the intervention of a therapist.

Trial Registration identifier: NTR6442

Van Klaveren, C., Kooiman , K., Cornelisz, I., & Meeter, M. (2018) “The Higher Education Enrollment Decision: Feedback on Expected Study Success and Updating Behavior“.  Journal of Research on Educational Effectiveness (JREE). 2018; 1-23


This study examines whether providing students with information on their future study success will influence their higher education enrollment decision and lower first-year dropout as a consequence. A randomized field experiment is conducted among 313 law and social science applicants at the Vrije Universiteit Amsterdam. The main results suggest that (a) students are generally overly positive about their future performance, (b) enrollment rates increase by 25% if students receive information on future study success, but (c) providing information to students does not reduce first-year dropout. An important conclusion is that the higher enrollment decision is not driven by the extent to which students are self-serving biased or by their updating behavior. Instead this decision seems to be influenced by a fear of failure, in the sense that students who receive a pass-signal (fail-signal) with respect to future study success enroll with higher (lower) probability.

Keywords: Self-serving biashigher education enrollmentrandomized field experiment

Cornelisz, I., & Van Klaveren, C. (2018) “Student Engagement with Computerized Practicing: Ability, Task Value and Difficulty Perceptions”. Journal of Computer Assisted Learning (JCAL). 2018; 1-15


A prerequisite for low‐stakes activities to improve learning is to keep students engaged when confronted with challenging material. Comparing a personalized and non‐personalized version of computerized practising, this study experimentally evaluates the relationships between student effort and ability across different dimensions of task perceptions. Students practise longer when the task is perceived to be not too difficult. Students assigned to a personalized version of the tool have a lower success rate while practising, but this does not translate to differences in practice intensity, task perceptions, or summative test scores. In a personalized practising environment, perceived interest and usefulness both have the potential to promote engagement, albeit in different ways. Students with a lower level of subject‐specific ability find the tool more interesting and, particularly, consider the non‐personalized tool difficult but useful. Instead, in the personalized condition, it is the group of students with higher prescores who value the tool as relatively useful. These results indicate that more students will remain engaged with adaptive practising if software takes into account such differences. Multiple approaches and algorithms may thus be necessary to optimally adapt practising to individual learners.

Van Halem, N., Van Klaveren, C. & Cornelisz, I. (2017). Oefent een leerling meer door niveaudifferentiatie? Het effect van data-gestuurde differentiatie op leerinspanning en de rol van eerder behaalde cijfers, Pedagogische Studiën, 94(3), 182-194.


While computer-based differentiation is increasingly common in education, no actual evidence on the effects on the learning process is established yet. This study investigates the effect of data-driven differentiation on students’ learning activity, and its relation with obtained summative grades. This study takes place over the course of one school year, in the context of the lower grades of secondary education and the courses biology, economics, and history. Students were randomly assigned to data-driven differentiation within an existing digital learning environment. Analyses were disaggregated into quartiles of students average achievement level and based on a longitudinal hierarchical regression model (N = 606), yielding the proportion of variance between and within students (over time). Results suggest that datadriven differentiation positively affects learning activity amongst certain – mostly high-achieving – students. Future research is required in order to fully explain these results and optimise datadriven differentiation in education.

Van Klaveren, C., Vonk, S. & Cornelisz, I. (2017). The Effect of Adaptive versus Static Practicing on Student Learning – Evidence from a Randomized Field Experiment, Economics of Education Review, 58, 175-187.


Schools and governments are increasingly investing in adaptive practice software. To date, the evidence whether adaptivity improves learning outcomes is limited and mixed. A large-scale randomized control trial is conducted in Dutch secondary schools to evaluate the effectiveness of an adaptive practice program relative to a static program. Learning theories predict that adaptive practicing is more effective, but this experimental evaluation provides a more nuanced picture. Relative to the static software environment, students working in the adaptive software environment receive more difficult exercises, practice longer and answer fewer questions correctly. Takeup and usage of the software program is, overall, modest, but varies considerably within and between classrooms. The outcome differences between both environments are more pronounced in classrooms with higher practice intensity. On average, no test score effects are found, but static practicing does improve test scores for higher ability students (0.08σ). Caution is thus warranted when adaptive practice software is implemented to address individual learning needs, as static formative test preparation can be more effective in improving test scores.