Foundation The Bridge Learning Interventions

Our mission

The Bridge Learning Interventions Foundation (TBLI) is dedicated to the consistently excellent implementation of evidence-based approaches powerful enough to generate breakthrough outcomes for vulnerable children and their caregivers. First and foremost, TBLI’s goal is to use High Dosage Tutoring (HDT) to help primary and secondary school students with – or at risk of developing – substantial learning deficits. With HDT, pupils ideally receive one-hour extra math tutoring every day, during regular school hours. They receive this from their own personal tutor in a 2-on-1 (i.e., 2 students on 1 tutor) configuration. This approach, HDT, boils down to promoting children’s cognitive and social-emotional development through strong and durable relationships between tutors and students. To strengthen this, tutors maintain weekly (telephone) contact with parents. Through the use of HDT, TBLI aims to eliminate educational disadvantages and to clear the way for successful school careers and life trajectories.

The High Dosage Tutoring approach

Precious few educational interventions are rigorously tested by means of Randomized Controlled Trials (RCT). Among those that are, only a small percentage create demonstrably positive results for the most vulnerable youngsters in our society. However, recent RCT-based research on HDT delivered by SAGA Innovations ( in Chicago has demonstrated that measurable results can be achieved with youth years behind their peers in math and other subjects. Through multiple RCTs, scholars based at the University of Chicago have pinpointed the reality of HDT driving massive gains. Pupils receiving this form of tutoring have gained from one to two extra years of math. Thanks in part to the strength of these RCT-based results, SAGA Innovations is one of the fastest growing non-profit organizations in Massachusetts and it is bringing HDT to children around the United States. TBLI’s approach to HDT is based on the work of, and supported by an ongoing partnership with, SAGA Innovations.

From September 2017 to January 2018, the first ever TBLI-delivered HDT program was implemented at a vocational secondary school in Amsterdam West. This school, Mundus College, serves students coming in, at age 12, an average of three years behind grade level in math. Preliminary results from a RCT conducted by a team of researchers based at the University of Amsterdam indicate – in terms of scores on standardized math tests – treatment effects on par with, if not greater than, those achieved in Chicago. The RCT-based study of TBLI’s efforts in Amsterdam also indicates positive and significant gains in socio-emotional development among pupils who received the tutoring.











Let us take a closer look: What are the main components of High Dosage Tutoring?

  1. A permanent tutor-tutee composition:Tutors are paired with a fixed number of tutees (pupils) during the year. The tutor and tutee get the chance to build a personal relationship, in which the tutors also serve as role models. The pupils are paired in fixed duo’s. The pupils in each duo are stimulated to work together as well as independently.
  2. Every day tutoring, integrated into the regular school day: HDT distinguishes itself from other types of tutoring, which are mostly offered during after school or outside school. Every day, every pupil has a tutoring-lesson during the regular school day. Therefore, HDT adds to and reinforces regular classroom instruction.
  3. One hour a day concentrated and tailor-made education: Thanks to the 2-on-1 setting, during tutoring sessions there are a few if any interruptions from peers. Tutors help, but where necessary also challenge and correct their tutees in settings devoid of the often-negative peer dynamics derailing many classrooms.
  4. A permanent tutor-classroom: The tutoring lessons take place in a permanent classroom with special furnishing and decoration. There are hand held whiteboards for every tutor and tutee, on which they can work on math problems in an interactive way. Thanks to careful lesson planning, tutors keep ahead of and tailor what will be offered each day to each tutees’ math skills and needs. Each tutoring lesson starts and ends with carrying out exercises in silence. Each tutoring lesson begins with a 1-minute meditation exercise.
  5. The tutors: Socially engaged and college educated (BA or MA level) people commit to a year of intense work as tutors. They must dedicate themselves to optimizing the chances of their pupils. The tutors are not required to have any specific didactic/pedagogic background but they do need to have the determination to develop their abilities to work within the HDT approach.
  6. The Site-Director: The Site-Director observes and supports the tutors during the (preparation of) lessons. Here continuous monitoring and feedback is the essential. The Site-Director watches every detail and is the ‘hands-on’ problem solver. Furthermore, the Site-Director is the main contact for schools and teachers regarding the development of the tutees and teaching materials.
  7. Weekly contact with parents/caretakers: Emphasizing the positive and hopeful aspects of what is going on, tutors proactively engage in contact with the parents (or caretakers) of their tutees by contacting them weekly by phone. Because of this investment in a healthy relationship with the parents, the parents can also be expected to act if motivational or behavioral problems arise in the tutorials. We also organize open days and evenings for parents to come and see a tutoring session.
  8. Working on a Growth Mindset through math: We try to replace the ‘Fixed Mindset’ with a ‘Growth Mindset’. Most disadvantaged pupils see math as a burden. They give up on math problems quickly and don’t see their usefulness or fun. The HDT-approach stimulates the tutees’ determination and tries to connect math to their direct environment, to give math a useful purpose. Facilitating the ‘Joy Factor’ during tutorials is a big part of successfully switching to a Growth Mindset.

Our HDT projects

HDT in lower secondary education

For a pilot study, one of our HDT-projects took place at a lower secondary high school in Amsterdam. The project, Mundus More Math [or M3], has run from September 2017 until February 2018. Why HDT in lower secondary education? Mostly students with the lowest secondary school level (i.e. vmbo and lwoo if not “practical” education) experience enormous educational disadvantages in the Netherlands. They enter pre-vocational secondary schools on average three or four years behind grade level in math. Furthermore, at the tender age 12 when they enter, few children are absorbed in ‘the streets’ when they start with their lower secondary education. They are however vulnerable to this. In a just few years, many of the pupils attending such stigmatized schools can be expected to orient themselves to local street culture—especially if they do not get the message that they can learn and perform well in school. Our assumption is that offering HDT at outset of these vulnerable students’ secondary educational careers their accumulated disadvantaged and learning deficits can be substantially reduced in ways that can help them avoid getting self- and other-destructive educational and life trajectories. We are confident that HDT can hugely increase chances that these students will receive diplomas and, in the longer term, that they will do well in worlds of work and in their communities. The longer-term goal, in other words, is to reduce the chances of vulnerable children’s lives will derail and to increase the chances that their overall life trajectories will improve.

HDT in upper primary school

Fifth graders (i.e., “groep 7” in Dutch) attending four different primary schools in Haarlem are participating in the first iteration of another project, “The Bridge Skills Lab – Haarlem”. This project will run from February 2018 until at least January 2021. The decision about extending the program indefinitely will be taken after two years, in the spring of 2020. Why HDT in upper primary school? Arguably the most distinctive feature of the Dutch school system is “early tracking” on to secondary school programs. This happens at age 12, and the tracking or selection is based largely on scores on standardized achievement tests at ages 10 to 12 years. As such, one might argue that the best way to disadvantaged students in the Netherlands is to help them achieve measurable boosts on these achievement tests before they are definitively tracked. In Haarlem, all the stakeholders felt strongly that HDT should be offered to students who had the most to gain from this intense approach and, therefore, it is being offered to students with the lowest math test scores at the end of fourth grade (“groep 6”). As is the case with other age groups, TBLI’s assumption here is to regular classroom instruction (i.e., one teacher and roughly 25 pupils) has not worked adequately for these students, and that a better match or fit between what they need and what they receive can be a game changer.

Scientific research

The University of Amsterdam is carrying out both quantitative and qualitative research examining the results of both of these HDT-projects. The focus of the research is on math-skills, social-emotional development and possible “spill-over effects” (e.g., that students will do better in non-math related subjects due to more self-confidence, a great sense of self-efficacy, or more parental engagement). A research team led by Dr. Bowen Paulle (Sociology, University of Amsterdam) is currently conducting this research as well as research on another project with a HDT-component in Rotterdam. This team has extensive knowledge of the HDT approach, and TBLI’s intention is to let this research team evaluate its projects in the future. Moreover, TBLI hopes that department of educational research of Centraal Planburau (CPB), which has advocated for bringing HDT to the Netherlands based on its success in the US, will be involved in the research effort.

Ideally, continuing research on our HDT projects will be based on Randomized Controlled Trial (RCT). In terms of pinpointing treatment effects, this is by far the most reliable research method. However, RCTs require certain minimal numbers of total pools of students that can randomly be assigned to either treatment or control groups (typically of the same size). As the decision was made to offer HDT only to relatively poorly performing students in Haarlem, a RCT for this project was not an option. There were not enough students scoring below the cutoff point. However, at the Mundus College, is RCT being conducted. Alongside this, through the use of qualitative research methods, the daily practices involved in the projects are being tracked. In this way, the research team can gain insight into the actual on the ground implementation.  This is crucial for those interested not just in HDT’s statistical effects but also in the primary processes driving them.
The first research results from our HDT project at Mundus College show that HDT had a huge significant and positive effect on the math scores of our students, also the effect size is very big for an educational intervention. This is especially remarkable because of the fact that the project only runned for 5 months (less than half a normal dosage of 10 months).


Our non-profit foundation has a tax deductible or, in Dutch, so-called ANBI-status. This status is granted to organizations that governmental authorities see as useful for Dutch society. Thanks in part to this status, support for The Bridge Learning Interventions projects comes in the form of grants from both governmental institutions and philanthropic organizations. A solid budget is needed for start-up costs (e.g. training of tutors, preparation of the intervention) and successful implementation of the tutoring. Often schools cannot fund such an intensive intervention alone. Every year we account for all of our income and expenditures in a publically available annual report.

If you want more information or if you want to financially support us, please contact our director Anne Kielman by mail: or phone: 06-21614658.

Our people
Chairman: Martijn van Tol, Treasurer: Tonnie Sonderen, Director: Anne Kielman.
For an overview of our current team of tutors in Haarlem, click here.