Scientifically Based Research

A report from

Research Does not Yet Exist to Support Any Program for Dyslexia

As of July, 2010, the US Department of Education had not been able to identify a single method or approach for dyslexia or learning disabilities supported by strong research.  See What Works Clearinghouse: Students with Learning Disabilities (archived page)

Out of 12 programs evaluated, 9 were deemed to have “No Studies Meeting Evidence Standards”.  That included well-established programs in use in many schools, including Orton-Gillingham based tutoring; Wilson Reading System, Alphabetic Phonics, and Barton Reading System.   That’s right — the traditional, phonics-based instructional approaches to dyslexia that schools today are most likely to offer in an IEP, and that parents are most likely to request – are not supported by even a single scientific study that passes muster, according to the US agency in charge of evaluating such research.

In fact, the ONLY phonics-based program supported by any research was Lindamood Bell LiPS based on a single study of 50 students, comparing the group receiving the LiPS program with a matched comparison group receiving an alternate, non-standard program developed for purposes of research. Based on that study, the Education Department reported that the extent of evidence was “small” with “potentially positive” effects for alphabetics and reading fluency, “no discernible effects” for reading comprehension, and “potentially negative” effects for writing (spelling).

Further, although not reflected in the ED agency report, the initial gains seen in the LiPS study were not sustained over time.  The author of the referenced study reported that after two years, there was no difference between either the intervention or comparison group, and students remained in the bottom  2% for reading fluency, with a large percentage showing no improvement at all.  See Figure 4 at p. 99 in Lessons Learned from Intervention Research.

More Research is Needed Before Limits are Placed

Does this mean that none of these programs work?  No — it simply means that it is very difficult for practical and ethical reasons to set up and complete high-quality, credible research studies involving schoolchildren.

The lack of solid research doesn’t tell us anything one way or another, but it is a good reason why it is premature for any laws that limit the types of programs that can be offered to dyslexic children.   A school cannot be mandated to provide something that doesn’t exist.

While it may seem like a good idea to pass a law requiring that all services be “evidence-based”, the research simply doesn’t yet exist to fulfill this goal. Laws that put such an impossible mandate in place can be misused. The most likely result is that schools will simply continue to use whatever curriculum or intervention they have used in the past, and the lack of good research will be raised as a barrier to school staff or parents who are looking for ways to try something new.

We believe that the laws need to recognize that research is ongoing, but children need help now.  Laws mandating services for dyslexic students should encourage flexibility and implementation of new and emerging methods, while also aiding in research by providing a mechanism for data collection and reporting when newer or experimental methods are put in place.

Thus, we cannot support any language that restricts available programs and support to dyslexic children to “scientifically-based” or “research-based” methods.  We don’t have anything against science or scientific research — the problem is the research needed has not yet taken place, and there is no agreed standard by which existing research can be evaluated.

Dyslexic Children Are Entitled to an Individualized Approach

It is also important to keep in mind that research studies produce statistical information potentially applicable to a large number of children, but students with learning disabilities in the US are entitled by law to an individualized education plan.   That means that even if an approach can be shown to be effective for 9 out of 10 children — through scientific evidence — the 10th child is entitled to help, too.  If that child is a “nonresponder” — one of the minority who do not benefit from the particular program — then both ethically and legally, the child should be entitled to a different intervention tailored to his or her individual needs.


As of 2017, the WWC has identified 5 additional programs which meet evidence protocols and show potentially positive effects for students with learning disabilities.  None of these programs involve phonics-based remediation to teach reading.  One of the programs, Spelling Mastery, includes phonemic, morphemic, and whole-word strategies to teach spelling skills.

For a full list of programs that have been evaluated by WWC in the context of students with learning disabilities, see Research Status – What Works Clearinghouse

You can also see a list of programs for struggling readers that have been evaluated in the context of the Every Student Succeeds Act here: Research Status – Evidence for ESSA

In 2021 a literature review and meta-analysis based 24 studies of Orton-Gillingham based teaching found no evidence of statistically significant differences in reading outcomes. The researchers expressed concerns about legislation mandating OG due to the lack of af an adequate research base. See Current State of the Evidence (Stevens, et al) (offsite link).

This page was updated on February 23, 2021.

5 thoughts on “Scientifically Based Research”

  1. Take a look at this study:

    Galuschka, K., Ise, E., Krick, K., & Schulte-Körne, G. (2014). Effectiveness of Treatment Approaches for Children and Adolescents with Reading Disabilities: A Meta-Analysis of Randomized Controlled Trials. PLoS ONE, 9(2). doi: 10.1371/journal.pone.0089900

    This meta-analysis study concludes that “[phonics instruction] is the only approach whose effectiveness on reading and spelling performance in children and adolescents with reading disabilities is statistically confirmed. This finding is consistent with those reported in previous meta-analyses [9,45]. At the current state of knowledge, it is adequate to conclude that the systematic instruction of letter-sound-correspondences and decoding strategies, and the application of these skills in reading and writing activities, is the most effective method for improving literacy skills of children and adolescents with reading disabilities.”

    Further, “phonemic awareness and reading fluency trainings alone are not sufficient to achieve substantial improvements. However, the combination of these two treatment approaches, represented by phonics instruction, has the potential to increase the reading and spelling performance of children and adolescents with reading disabilities.”

    For some reason, WWC looks favorably on 3-cueing system reading approaches (LLI, Reading Recovery) by approving only those studies conducted by the publishers, which, if you look at the studies’ data, do not show the benefits that the authors claim. On the other hand, WWC judges phonics programs such as Wilson poorly because they don’t address all 5 pillars of literacy instruction. Yet these programs are not intended to address all 5 pillars. WWC is not willing to judge these programs on their own terms. WWC is not as uniformly trustworthy as one would hope.

    • Thank you for sharing that link. You can find the current WWC protocols for students with learning disabilities here:

      Some of the key points for the WWC protocol are:

      > The studies must be conducted in the US or a US territory.
      > At least 50% of participants must be classified with a learning disability.

      The WWC protocols do NOT require that studies report on multiple outcomes — (“address all 5 pillars of literacy instruction”) — but approaches that show positive results under more than one outcome would likely end up being ranked higher in terms of effectiveness.

      The meta-analysis you cited includes studies from “various English-speaking and non-English-speaking countries like Finland, Italy, Spain, and Brazil” — and doesn’t specify how many are US-based — and it doesn’t specify whether any students within the study groups had been screened for learning disabilities — so it is unclear whether any of the studies would have qualified under the WWC standards.

      The programs you mentioned (Reading Recovery, LLI) are NOT among the studies listed as qualifying under the specific learning disabilities protocols – — as neither are programs targeted toward dyslexia or related learning differences.

      Since this website is focused only on policy concerns specific to dyslexic learners, we have not tried to index or report on more generalized studies of educational programs and literacy achievement. We would expect that dyslexic children, by definition, will be disproportionately clustered around the tail end of any distribution in any group that includes non-dyslexic children. That means that even when there is an instructional method or intervention that is shown to have positive effects in general, it is very possible that all or most of the dyslexic children in the group are among those not represented in calculating effect size.

      The only way to get around that with statistical research is to look at studies where the students in the study group are known to either be dyslexic or clearly at-risk for dyslexia. There are enough studies showing divergent learning characteristics among dyslexic readers to establish that findings about reading instruction and learning among broader groups of children cannot be generalized as being applicable to dyslexic learners, because of inherent, brain-based differences. There certainly could be many areas of overlap, but for purposes of research it is important to look to studies that are specific to dyslexia to tease out what is generally effective best for dyslexic kids from what may be generally effective for the majority of kids.

  2. This seems ridiculous… how long does such a study take? Who is responsible for the research? What methods are currently being studied? When will SOMETHING be completed?

  3. Sally Shaywitz has conducted a considerable amount of brain research, but no research at all into educational methodology. So her research is valuable but does not support any particular method or approach for dyslexia.

    Joseph Torgesen is the director of the Florida Center for Reading Research, and he has written extensively about the high failure rate of many “traditional” approaches to dyslexia. His center produced a 2004 report into Orton-Gillingham which contained the following conclusion:

    “A search of the research literature for studies examining the efficacy of the
    Orton-Gillingham Approach did not identify any empirical studies of this
    approach implemented specifically as described in the Orton-Gillingham
    training materials….. [T]here are no studies available at present to provide an estimate of its impact
    on the reading growth of young children”


    Obviously, there are many researchers who are working on developing a body of research to support various interventions. They are to be commended for their work.

    But it is equally true that as yet, there is very little available research that can support broad conclusions as to educational methodology. The What Works Clearinghouse reports indicate that in most cases, reported research simply does not meet rigorous standards.


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