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A review of three controversial educational practices: perceptual motor programs, sensory integration, and tinted lenses.
Article Type:
Report
Subject:
Disabled children (Education)
Disabled children (Psychological aspects)
Perceptual-motor processes (Management)
Psychotherapy (Methods)
Psychotherapy (Educational aspects)
Authors:
Hyatt, Keith J.
Stephenson, Jennifer
Carter, Mark
Pub Date:
05/01/2009
Publication:
Name: Education & Treatment of Children Publisher: West Virginia University Press, University of West Virginia Audience: Professional Format: Magazine/Journal Subject: Education; Family and marriage; Social sciences Copyright: COPYRIGHT 2009 West Virginia University Press, University of West Virginia ISSN: 0748-8491
Issue:
Date: May, 2009 Source Volume: 32 Source Issue: 2
Topic:
Event Code: 200 Management dynamics Computer Subject: Company business management
Geographic:
Geographic Scope: United States Geographic Code: 1USA United States

Accession Number:
199854573
Full Text:
Abstract

Children with disabilities have frequently participated in various interventions before the efficacy of those practices was scientifically validated. When subsequent scientific evidence failed to support particular practices, those that had already made inroads into the educational arena frequently continued to be used. Given the current emphasis on the use of empirically validated interventions, a review of research on the efficacy of educational interventions is consistent with guidelines from the No Child Left Behind Act (2001) and the Individuals with Disabilities Education Act (2004). The research findings regarding three relatively common, yet controversial, practices failed to support the continued use of perceptual motor programs, sensory integration therapy, and tinted lenses. Educators are encouraged to become informed consumers of research and implement evidence-based practices.

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In recent years, journal articles and entire books have been written to alert educators, parents, physicians, psychologists, and other professionals of the inherent problems associated with the use of nonvalidated practices in the treatment of individuals with disabilities (e.g., Jacobson, Foxx & Mulick, 2005; Lilienfeld, Lynn, & Lohr, 2003; Rooney, 1991; Sieben, 1977; Silver, 1995; Stephenson, 2004). In spite of efforts of those in the held to ensure that scientifically validated interventions are the treatments of choice, nonvalidated approaches continue to hold a considerable amount of influence on the perceptions of many professionals and the public. The American Academy of Pediatrics (1999) recommended training new physicians about discredited practices, such as the Doman-Delacato patterning treatment, to avoid repeating mistakes of the past. This is an important recommendation that is just as relevant for educators as it is for physicians.

While the use of a nonvalidated approach may not pose an imminent threat to the safety of individuals, it could deprive people of exposure to effective interventions, waste valuable time, and provide false hopes that may lead to feelings of discouragement after the approach fails to produce the desired outcome. An internet search on the practices discussed in this paper would lead the reader to many sites containing persuasive advertisements and testimonials claiming the effectiveness of the treatments without citing support from empirical research reported in peer-reviewed papers. To this end, it is imperative that professionals become informed consumers of research to ensure that those seeking assistance are provided with treatments or interventions that will most likely result in improved learning and an increased quality of life.

The purposes of this paper are twofold. First, the review will consolidate available research evidence and inform professionals of the lack of scientific substantiation for the continued use of three controversial practices: perceptual motor programs (PMPs), sensory integration, and tinted lenses. Second, parallels will be drawn between these three approaches with the intent of assisting consumers of research to understand why they continue to be employed and how to identify potentially ineffective practices. The three practices discussed in this review have been selected among the many unsupported or controversial practices because there is a long history of their use with students with disabilities and learning difficulties (Kavale & Mostert, 2004; Whitely & Smith, 2001). It is our intention to draw to the attention of practitioners the nature of the evidence available on the efficacy of these practices. To achieve this goal, definitions of each practice, a description of the procedures along with a rationale for those procedures and relevant research findings will be presented for each practice. Where systematic meta-analyses have been conducted (i.e., PMPs and sensory integration), key reviews will be synthesized and recent studies will be considered where relevant. Unlike PMPs and sensory integration, tinted lenses have not been subject to systematic meta-analysis so primary sources of research will be examined. Finally, some common characteristics of these approaches will be discussed along with an exploration of reasons they continue to be employed.

Perceptual Motor Programs

Definition

Perceptual motor skills are those that require the integration of sensory input (visual, auditory, and kinesthetic) with fine or gross motor responses. Perceptual Motor Programs (PMPs) for students who have difficulty learning are based on the notion that neurological problems causing particular processing deficits related to the integration of perceptual and motor skills interfere with academic learning (Blythe, 2000; Dore, 2006). Despite professional concerns regarding the existence of processing deficits, interventions for learning difficulties that purport to remediate these underlying process deficits remain popular. Perceptual-motor training has been the most prevalent type of process training and remains alive and well (Kavale & Forness, 2000). Many older PMPs such as the Doman-Delacato patterning program continue to be advertised, although they have been discredited (American Academy of Pediatrics, 1999; Jacobson, Mulick, & Foxx, 2005), and many newer programs such as the Dore/DDAT, Primary Movement Program and Brain Gym[R] have emerged with a range of theoretical underpinnings.

Description of Practice for Perceptual Motor Programs

Currently widely advertised programs such as the Dore Achievement Center's individualized Dyslexia, Dyspraxia and Attention Treatment (DDAT) are based on the claim that the difficulties lie in the cerebellum (Dore, 2006). Treatment consists of exercise programs that are claimed to improve the ability of the cerebellum to process information. It is purported that children with dyslexia have a core difficulty with skill automization, which impacts language and reading. This difficulty has been called Cerebellar Developmental Delay (DDAT, 2006a) by the Dore centers, a label that is not used by any other group. Dore centers claim that their individually designed exercise programs improve cerebral functioning thereby overcoming automization deficits and subsequently improving academic and social skills (DDAT, 2006b; Fawcett, Nicolson, & Maclagan, 2001; Reynolds, Nicolson, & Hambly, 2003)

Other current perceptual-motor theories ascribe difficulties in learning to the persistence of primitive reflexes which then impede normal development and the ability to learn skills such as reading and writing (Goddard-Blythe, 2000; Institute for Neuro-Physiological Psychology, n.d.; Jordan-Black, 2005; McPhillips, Hepper & Mulhem, 2000). These theories underlie the Primary Movement program developed by McPhillips and programs promoted by the Institute for Neuro-Physiological Psychology (INPP). Programs such as Brain Gym [R], which are promoted as improving learning, sport and self management skills in anyone (Brain Gym [R], 2006a), rely on much more general and simplistic notions of improving brain function. Brain Gym [R] promotes exercises claimed to facilitate the integration of the front and back parts of the brain, the right and left hemispheres, and the top and bottom parts of the brain to improve a wide array of unrelated behaviors such as reading, surfing, golf, and sales. (Brain Gym[R], 2006b; Hyatt, 2007). In essence, PMPs imply that relatively simple exercises can fundamentally change the neural structure of the brain and facilitate learning.

PMP programs prescribe particular motor activities and exercises. Some, such as in the Dore/DDAT program maybe individually prescribed and adjusted (Reynolds et al., 2003), while others may be generic (Brain Gym [R], 2006b). They often include activities, such as throwing and catching, purported to improve balance, gross and fine motor skills, and academic achievement. The exercises may involve doing two things at once; for example, one exercise in the Dore/DDAT program involves sitting and bouncing on a large air filled ball while tossing a bean bag from hand to hand (DDAT, 2006a).

The persistence of primitive reflexes is another rationale given for programs that prescribe exercises that mimic the activities of fetuses and infants such as crawling and stretching or movements based on those reflexes (Goddard-Blythe, 2005; Jordan-Black, 2005; McPhillips et al., 2000). The claim is made that movements that follow the pattern of the reflexes will work to inhibit those reflexes and somehow improve the ability to acquire reading and other academic skills (McPhillips et al.).

Research Findings for Perceptual Motor Programs

Kavale and Mattson (1983) completed a meta-analysis of 180 studies of PMPs and found a very small overall effect size of .08. Effect sizes were reported for outcome measures (reading, intelligence, general achievement as well as perceptual and motor skills), specific training programs, different groups of children, and different grade levels and no important positive effects were found. Indeed the effect size for perceptual-motor outcomes was only 0.17 which is also very small and suggests that the programs examined had little impact even on perceptual-motor skills themselves. The Board of the Trustees of the Council for Learning Disabilities (Council for Learning Disabilities, 1987) issued a strong statement in 1986 against the use of perceptual motor testing and training to improve academic performance, perceptual, and perceptual-motor functions in students with learning disabilities. They based this recommendation on the lack of scientific evidence supporting such practices.

Hyatt (2007) reviewed the research on Brain Gym [R] and found that the limited peer-reviewed research available failed to support claims that Brain Gym [R] resulted in improvements in academic learning. There are two reported studies of the DDAT exercise-based approach (Reynolds et al., 2003; Reynolds & Nicolson, 2007) but the flawed research design and difficulties with the analysis and inter-pretation of results make the evidence supporting the efficacy of the approach unconvincing (Alexander & Slinger-Constant, 2004; Rack, Snowling, Hulme & Gibbs, 2007; Snowling & Hulme, 2003). Summaries of several small, in-house studies in schools in the UK and Germany on the effects of a program designed by the INPP to reduce the persistence of primitive and postural reflexes and to improve academic performance, particularly reading, were presented by Goddard-Blythe (2005). None of these studies showed that the program had important effects on reading, and in most sites there was no effect on reading.

There are two research studies (Jordan-Black, 2005; McPhillips et al., 2000) that reported positive effects on reading and math but not spelling after the use of the Primary Movement Programme developed by McPhillips, but there are limitations to these studies and the results need to be replicated by other researchers prior to acceptance. The assessment of the persistence of primitive reflexes was carried out using observation and scoring on a four point scale of the movement of the arms in response to having the head turned (Schilder test). Neither McPhillips et al. nor Jordan-Black provide information on the origins, reliability, or validity for this test nor did they carry out inter-observer agreement measures in their studies which would establish that the same actions would be scored the same way by two independent observers. Both reports also note that the reduction in the reflexes is claimed only to increase "readiness" to learn and the program is not a substitute for instruction. Given the lack of impact of older PMPs on reading and that the exhaustive review of the correlates of reading carried out by Hammill (2004) found only small correlations between reading and perceptual-motor skills, it is hard to be optimistic that these newer programs will be any more successful than the older programs.

Sensory Integration

Definition

Sensory integration arose from the work of Ayres (see Ayres, 1972) and was popularized in the 1970's. It has been applied to a variety of groups including those with learning difficulties (Hoehn & Baumeister, 1994), cerebral palsy (Chu, 1989), intellectual disability (Arendt, MacLean, & Baumeister, 1988a) and autism (Dawson & Watling, 2000). Much of the early research addressed children with learning disabilities, with the expectation that underlying academic performance would improve with sensory integrative therapy (Vargas & Camilli, 1999). More recent research has often focused on addressing unusual responses to sensory input, particularly in children with autism spectrum disorders (see Baranek, 2002; Dawson & Watling, 2000). A fundamental assumption underlying sensory integration is that learning and other problems arise, at least in part, from difficulties in the neurological processing of vestibular, tactile and proprioceptive sensory information (Arendt et al., 1988a; Ayres, 1972; Bundy & Murray, 2002; Hoehn & Baumeister, 1994). Higher-level functions, such as those involved in traditional academic skills, are assumed to be dependent on lower-level processing of sensory information (Hoehn & Baumeister, 1994). The basic premise that higher cognitive and functional skills are dependent on more fundamental abilities is common among perceptual motor programs. Sensory integration, however, is distinguished by the apparent complexity of its underlying neurophysiological theory and thus it warrants separate consideration.

Description of Practice for Sensory Integration

Sensory integrative therapy is usually conducted by occupational therapists and treatment is costly, with intervention sometimes lasting more than a year (Vargas & Camilli, 1999). In a review of sensory integration research, Vargas and Camilli reported that intervention averaged 60 hours (range 13-180), involving between two and five sessions per week, each of 25-45 min duration. Interventions involve a range of activities that typically include the combination of controlled sensory stimulation and "purposeful" motor activity (Ayres, 1972; Bundy & Murray, 2002; Hoehn & Baumeister, 1994). Therapy may involve the use of equipment such as hammocks and scooter boards to provide vestibular stimulation, use of weighted vests, manual compression of joints, as well as brushing and rubbing of the body with materials of various textures (see Ayres, 1972; Hoehn & Baumeister, 1994; Smith, Mruzek, & Mozingo, 2005). A related intervention involves the use of "sensory diets", including activities and environmental adjustments, which are presumed to match the individual's sensory needs (Smith et al., 2005). For example, if a child is over-aroused, calming vestibular activities such as rocking or riding a bike might be advised (Yee, 2007).

Research Findings for Sensory Integration

The ongoing interest in sensory integration has resulted in reviews of its efficacy in several areas and key reviews will now be synthesized. In examining the application of sensory integration to individuals with intellectual disability, Arendt et al. (1988a) described a small and deeply flawed body of research that provided no empirical support for the continued use of the procedure in clinical contexts. Hoehn and Baumeister (1994) found similar results in their review of research on sensory integration with individuals with learning disabilities. Following analysis of seven outcome studies published after 1982, they concluded that the "current fund of research findings may well be sufficient to declare SI therapy as not merely unproven, but a demonstrably ineffective, primary or adjunctive remedial treatment for learning disabilities and other disorders" (p. 348).

Sensory issues affecting individuals with autism have been of interest in recent years and sensory integration has been suggested as a possible strategy to address these problems (Dawson & Watling, 2000). Dawson and Watling located four relevant studies in their review and concluded that "these were of such small scale that no firm conclusions regarding efficacy could be made" (p. 415), although even this interpretation may have been overly generous (see Goldstein, 2000). In a later review, Baranek (2002) examined only three studies, identifying important weaknesses in each that made it difficult to ascribe any observed changes to sensory integration per se. Baranek's recommendation supporting the cautious use of sensory integrative therapy seems unjustifiable given the number of studies examined, acknowledged flaws, and inconsistent treatment effects. Substantial integrative reviews of intervention options in autism (Lord & McGee, 2001; New York State Department of Health, 1999; Perry & Condillac, 2003; Roberts, 2004) have consistently concluded that there is no credible empirical base to support the application of sensory integrative therapy Even those recommending the use of sensory integration in autism (e.g., Baranek, 2002) or suggesting it may have promise (e.g., Heflin & Simpson, 1998) concede that there is currently no valid empirical evidence base for the technique.

In addition to descriptive reviews of sensory integration in specific areas, quantitative meta-analytic syntheses have been conducted. Ottenbacher (1982) provided a meta-analysis of the small body of early research on sensory integration, examining eight studies published prior to 1982. These initial findings were encouraging with an overall effect size of .79. Unfortunately, this very early promise has been comprehensively disconfirmed in later and larger analyses. Vargas and Camilli (1999) provided a meta-analysis of 23 studies comparing sensory integration to no treatment controls or other interventions. When compared with no treatment, the mean effect size was .29. While this was statistically significant, it fell short of the third of a standard deviation difference that is typically used as the threshold for educational significance. Vargas and Camilli confirmed the results of the earlier Ottenbacher meta-analysis but found that effect sizes fell to .03 in post-1982 studies. When compared with alternative treatments, the overall effect size was .09, which was not statistically significant from zero. A similar pattern of results was presented by Shaw (2002) in summarizing a meta-analysis of 41 sensory integration studies employing random assignment. Effect sizes for improvement in language (-.08), behavior (.02) and sensory motor functions (-.10) were not statistically significant. Small but significant effects were found for motor skills (.24) and psychoeducational performance (.26) but these dropped to near zero for studies that controlled for maturation. Sensory integration is an expensive intervention and available review data overwhelmingly suggests it is manifestly ineffective.

Sensory integration has sometimes been defended by reversing the conventional scientific burden of proof. Conventionally, the onus of proof rests with those proposing an intervention to demonstrate that it does work. In the case of sensory integration, it is sometimes argued that critics have failed to demonstrate that it does not work (e.g., Ottenbacher, 1988). The end point of this line of reasoning is demonstrated by Miller (2003) with an argument that amounts to the justification of continued clinical use of sensory integrative therapy on the basis of a perceived lack of interpretable scientific evidence. Indeed, Shaw's (2002) suggestion that sensory integration exhibits many core features of pseudoscience should not be dismissed lightly.

Despite a consistent lack of supporting evidence, sensory integration has been highly enduring (Smith et al., 2005). For example, Green et al. (2006) reported a survey of over 500 parents of children with autism in which sensory integration was reported as the third most commonly implemented treatment, ahead of interventions with solid empirical support such as applied behavior analysis. It is possible that this resilience may be a product of incorrect perceptions of parents and educators that sensory integrative therapy may be having an effect. Mason and Iwata (1990) have clearly demonstrated experimentally that apparent effects of sensory integrative therapy may be artifacts and unrelated to the therapy itself. Part of the basis for this resilience may also relate to the view that research on sensory integration is in its infancy (Miller, 2003) and that research will eventually catch-up with professional beliefs (Schaaf & Miller, 2005; Smith et al., 2005). This would seem increasingly unlikely noting that sensory integration theory and research now dates back around 40 years. To put this in context, sensory integration emerged as a field of research at around the same time as applied behavior analysis. Even if the contentious argument that sensory integration is unproven rather than disproved is accepted, the question arises as to whether the public should continue to be exposed to an unproven intervention?

Tinted Lenses and Overlays

Definition

Irlen (1991) reported that during the 1980s she had chanced upon an amazing discovery when working with adults with reading problems, the identification of a previously unknown visual-perceptual problem that interfered with a person's ability to process full spectrum light. She coined the condition Scotopic Sensitivity Syndrome (SSS), which is also known as Irlen Syndrome (The Irlen Institute, n.d.) and Meares-Irlen Syndrome (The Institute of Optometry, n.d.). Some of the postulated symptoms of SSS included text appearing blurred, spaced as if a river were running down the page, and letters appearing to swirl or shake. Irlen theorized that SSS was the reason many people experienced difficulty in a wide range of important life activities that included reading, attitude, motivation, self-esteem, depth perception, sports, movement, coordination, music, math, handwriting, and writing composition, and claimed that the perceptual difficulties of individuals with SSS could be ameliorated with the use of colored overlays or tinted lenses. Unlike the reviews of PMP and sensory integration, the following discussion is based on primary sources, because there were no meta-analyses identified in a search of the ERIC, PsychINFO, and MEDLINE databases between 1990 and 2006.

Description of Practice for Tinted Lenses and Overlays

The use of tinted lenses and overlays has been promoted by two agencies, the Irlen Institute for Perceptual and Learning Development in the United States and The Institute of Optometry in the United Kingdom. It is unclear how widespread the use of tinted lenses is; however, the Irlen International Newsletter (New Screeners, 2006) listed the following number of new screeners in various countries: United States, 402; England, 93; Canada, 30; Australia, 24; South Korea, 17; Austria, 8; New Zealand, 5; Hong Kong, 2; Jordan, 2, Slovenia, 1, Switzerland, 1, Slovenia, 1. The estimated the number of screeners is approximately 7000 worldwide with over 100.000 people using Irlen lenses (Othmer, 2006).

Both organizations claim that colored overlays are effective treatments for visual-perceptual problems and SSS. They also assert that the colored overlays must be specifically manufactured and note that colored overlays purchased from office supply stores would not suffice; however, they provide no research support for this contention (The Institute of Optometry, n.d.; The Irlen Institute, n.d.).

The two session assessment conducted by Irlen examiners is only briefly described in Irlen materials. In the first session, an interview is conducted, visual-perceptual tasks are administered, and for those deemed to have SSS, colored overlays are provided. The individual is told to use the overlays and return for a Tinting Assessment if the use of colored overlays significantly improved reading. The assessment conducted by The Institute of Optometry is similar and may include an eye examination, an interview, and a Colorimetry assessment if necessary. The Colorimetry assessment is conducted with an Intuitive Colorimeter, a device developed to prescribe colored overlays and lenses. However, identification of colored overlays in the studies reviewed was frequently done through a subjective process of elimination where subjects were shown various tints and asked to select the best. Kriss and Evans (2005) noted difficulties with objective assessment of Irlen syndrome and stated that diagnosis is typically based upon whether the individual reported immediate improvement or voluntarily used the overlays for a sustained period of time. While individual reporting may reflect actual change for the person, reliance on subjective reporting could be misleading, because an individual may provide a report to please the investigator, the positive report may be a result of the placebo effect, or it could represent actual change. It would be important to clarify this issue in future research using controlled measures.

Research Findings for Tinted Lenses and Overlays

Before reviewing research studies that investigated the use of colored lenses, a few background issues must be addressed. First, several researchers have noted the absence of objective scientific evidence that Scotopic Sensitivity Syndrome actually exists (Blaskey et al., 1990; Rooney, 1991; Royal College of Ophthalmologists, 2002; Silver, 1995; Stone & Harris, 1991; Woerz & Maples, 1997). Second, Irlen and The Institute of Optometry claimed that the symptoms of SSS are not detectable by standard vision examinations; however, Solan (1990) and Williams, Kitchener, Press, Scheiman, and Steele (2004) noted that the identified symptoms of SSS are related to identifiable vision anomalies. Furthermore, while vision problems must be corrected so that children can see the printed word, the contention that neurologically based visual-perceptual problems are one cause of learning disabilities has not been substantiated (American Academy of Pediatrics, 1998; Helveston, 1987; Metzger & Werner, 1984). When considering that SSS is supposedly related to the visual system, it is of interest to note that the majority of studies reviewed did not require a vision examination as part of the study. If addressed, most noted that the subjects had received an exam in the past. For example, Kriss and Evans (2005) stressed the importance of vision examinations, but still failed to conduct vision exams prior to conducting their study. Finally, while both the Irlen Institute and the Institute of Optometry claim to have unique procedures for diagnosing and manufacturing the appropriate tint, no research was located comparing the effectiveness of the different assessment procedures or tints prescribed by either organization.

In addition to the disagreement regarding the existence of SSS as a unique perceptual disorder, there is a lack of documentation supporting the consistency in which individuals select overlays (Fletcher & Martinez, 1994). Woerz and Maples (1997) conducted a study with 41 high school students to determine the consistency of student selection of tinted overlays. In a visual activity in which 24 differently colored overlays were used, students self-selected the overlay that made the task easier to complete. Two weeks later, the students were again asked to select a preferred overlay, and only fourteen students (34%) selected the same color. When comparing the performance of the 19 students identified as SSS symptomatic, the results were even worse with only 5 (26%) of 19 choosing the same color on retest. Another study conducted by Wilkins, Lewis, Smith, Rowland, and Tweedie (2001) examined the consistency of color selection of 87 students in grades four through six in one school. They reported that 47% selected the same color on the second assessment. Unlike Woerz and Maples, they did not report data on SSS symptomatic students separately.

In spite of the absence of scientific evidence supporting the existence of SSS or the consistency of colored overlay selection procedures, a considerable number of studies were conducted to evaluate the efficacy of colored overlays. In 1990, the Journal of Learning Disabilities published a special issue that provided intensive coverage of Irlen lenses. In the preface to the issue, the editor in chief, Wiederholt, noted that each of the studies had serious theoretical, medical/physical, and methodological flaws, but were published along with articles critiquing the studies to provide readers with an overview of the Irlen procedures as well as guidance for conducting quality research studies. He, along with Hoyt (1990), Parker (1990), and Solan (1990), noted that these initial studies by Blaskey et al. (1990), O'Connor, Sofo, Kendall, and Olsen (1990), and Robinson and Conway (1990) failed to support the treatment validity of colored overlays.

A brief description of representative studies conducted on both Irlen and Intuitive overlays is contained in Table 1. The considerable variability in the findings may be a result of methodological flaws similar to those identified by Parker (1990). Some of the inadequacies included: subjective and anecdotal reporting, failure to control for placebo effect, lack of control groups, failure to determine equivalence of groups at pre-test phase, use of multiple treatments with one group, application of multiple statistical analyses without correction for false positives, failure to control for external threats to validity, possible experimenter bias, and use of inappropriate measurement metrics, such as reading age-equivalent scores. Given these concerns with the research designs, it should not be surprising that there is considerable variability in findings reported in Table 1.

Some key issues arising from the research on Men overlays will be discussed followed by a review of research on Intuitive overlays. None of the studies included a control group who met the criteria for SSS. In fact, Robinson and Conway (1990) stated, "A control group was not included, due to the ethical concerns of denying treatment for 1 year" (p. 590). Hoyt (1990) expressed concern that this statement implied that the researchers were convinced of the validity of Irlen lenses as a treatment approach prior to conducting the study, which raised a fundamental concern related to researcher bias. Despite this concern, future studies by Robinson and Foreman (1999a, 1999b) also included the same justification for exclusion of a control group with SSS symptoms. In addition to problems inherent with lack of control, Robinson and Foreman (1999a, 1999b) subjected two of three experimental groups to more than one treatment, so any findings for those groups could not be attributed to a single experimental condition. They also failed to control for internal and external threats to validity such as subject maturation or changes in schooling conditions.

Several studies also used inappropriate measurement metrics and statistical analyses. Reading age was used as a measure of performance in several studies (Christenson, Griffin, & Taylor, 2001; Martin, Mackenzie, Lovegrove, & McNicol, 1993; O'Connor et al., 1990; Robinson & Conway, 1990; Robinson & Foreman, 1999b, Saint-John & White, 1988). Salvia, Ysseldyke, and Bolt (2007) provided strong cautions regarding the use of developmental equivalents, such as reading age, noting that the ordinal nature of these measures precludes their use in most statistical computations. Other researchers also used nonstandard measurements in their studies. For example, Lopez, Yolton, Kohl, Smith, and Saxerud (1994) conducted statistical analyses using percentile rankings, which were inappropriate for the statistical analyses conducted. Due to the nature of ordinal scores, the findings in these studies must be viewed with extreme caution.

In an additional study on Irlen overlays, Whichard, Feller, and Kastner (2000) evaluated the effectiveness of Irlen overlays on 72 prison inmates. Based on subjective reports from the volunteers, they determined that the lenses were effective as 40 of the subjects reported considerable improvement in reading. However, this report cannot be accepted with any level of confidence as there was no control group and no objective measure of reading skill before or after selection of colored overlays.

Several studies listed in Table 1 were conducted to evaluate the effectiveness of the Intuitive colored overlays. As with the studies on Irlen overlays, the research studies on Intuitive overlays did not include control groups, did not ensure group equivalence prior to interventions, and included the use of questionable statistical procedures. For example, Bouldoukian, Wilkins, and Evans (2002) noted that some of the subjects had been using overlays for several weeks prior to participating in that study and approximately one-third had been performing eye exercises prior to the study. So group equivalence could not be assumed. In addition, Wilkins et al. (2001) in the third study reported in that article stated "To save time on testing, only children who chose an overlay were tested" (p. 55), thus, there was no comparison group. The statistical analyses were also of concern and included the use of multiple t-tests without controlling for Type I error and the use of one-tailed t-tests (Scott et al., 2002; Wilkins et al., 2001). Both of these procedures increase the chance of finding a significant difference where one did not exist, thereby, limiting the confidence that could be afforded to these findings.

In contrast to studies using Irlen lenses, the studies involving Intuitive overlays tended to demonstrate an increase in reading speed as measured by the Rate of Reading Test (RRT). Wilkins, Jeanes, Pumfrey, and Laskier (1996) described the RRT, developed by Wilkins, as a test that minimized the linguistic aspects of reading by using only 15 common words and maximized visual difficulties due to spacing, font type, and font size. They stated that multiple equivalent forms were available but provided no evidence of alternate form reliability.

A reliability study of the RRT described by Wilkins et al. (1996) was conducted with 77 students who ranged in age from 8-8 to 11-9 and were in the fourth, fifth, or sixth grade. No other information regarding the sample was provided. While they did find an acceptable correlation, the study was not conducted in the same manner for all students, which brings into question the level of reliability they reported. Due to the varied nature of the assessment, the small experimental group, nonexistent alternate forms reliability measurement, and limited demographic data, one cannot accept the reliability of the RRT as presented. In addition to questions about the reliability, there remain questions regarding the concurrent and predictive validity of the RRT; perhaps most pressing is whether performance on the RRT is related to actual reading tasks and school performance. The RRT may in fact be an acceptable measure of reading speed, and future comparative research could confirm or disaffirm its use as a reading assessment instrument.

Northway (2003) identified changes in reading rate on the RRT that were accompanied by large standard errors of measurement. In this study, subjects who did not choose an overlay actually demonstrated a decrease in rate of -2.4 words per minute [+ or -] 4, those who chose an overlay but didn't use it also demonstrated a decrease of -4.4 [+ or -] 9, and those who reported frequent use of the overlays demonstrated an increase of 10.2 [+ or -]. 13. In all cases, the standard error of measure was greater than the change in performance. It is possible that the large standard error of measure could be related to the use of gain scores which are not recommended for analyses due to unknown reliability of gain scores (Thorndike & Dinnel, 2001). Additionally, test results which demonstrate large standard errors of measure should be interpreted cautiously because the large error could be due to low reliability of the measure (Salvia et al., 2007).

In summary, the research conducted on tinted lenses has failed to demonstrate the efficacy of the practice. The often conflicting findings between research studies conducted on Irlen lenses with those conducted on Intuitive lenses may be related to study designs, participants, the use of different reading assessments, or even the overlays themselves. The Royal College of Ophthalmologists (2002) noted that the majority of studies in the literature were poorly designed, but did encourage controlled research to seriously investigate the issue, as did the American Optometric Association (Williams et al., 2004). However, neither organization implicitly recommended the use of colored lenses at the present time. The American Academy of Pediatrics in a joint statement with the Committee on Children with Disabilities, the American Academy of Ophthalmology, and the American Association for Pediatric Ophthalmology and Strabismus (1998) took a stronger position and firmly repudiated the use of lenses, stating that there was no scientific evidence supporting their use. In fact, they noted that the expense of such treatment is unwarranted and may provide parents and teachers with a false sense of hope. Following a review of research related to Irlen lenses, Kavale and Mostert (2004) stated, "Irlen lenses need to take their place in the history of interventions that have been tried in the name of special education but failed" (p. 173). Despite these concerns from noted professional organizations, Kriss and Evans (2005) stated that many individuals without reading difficulties would benefit from the use of colored overlays.

Discussion

Summary

This review has focused on three practices that have generated controversy regarding their efficacy. Research on the oldest of the three, PMPs has failed to support their use for remediation of academic difficulties since the original Kavale and Mattson (1983) review, yet many still persist in various guises. Sensory Integration has been researched for over 40 years and there has been a failure to provide convincing evidence suggesting it is effective with any diagnostic group. The more recent entrant, tinted lenses, shares the same premise as the older practices: It appears to assume that there is some underlying deficit in students with disabilities that can be addressed and that the proposed intervention will lead to improvement in academic functioning.

These practices share other common features, such as unique clinical constructs, terminology, and assessment practices, which have also been identified as characteristic of other controversial treatments (Vyse, 2005). The use of clinical constructs, such as Sensory Integrative Dysfunction, Cerebellar Developmental Delay and Scotopic Sensitivity Syndrome which are claimed to underlie and "cause" particular difficulties provides a plausible rationale for the treatments, but these conditions are not generally recognized outside the particular controversial practice. For example, none of the disorders are recognized in DSM-IV-TR (American Psychiatric Association, 2000) and they are not consistent with accepted neurological theory. It is often specifically argued that sensory integration is consistent with our understanding of neuroscience (e.g., Dunn, 1988; Heflin & Simpson, 1998). In reality, however, sensory integration theory is highly speculative and there are significant reasons to question its conceptual foundation (see Arendt et al., 1988a; Arendt, MacLean, & Baumeister, 1988b; Hoehn & Baumeister, 1994; Smith et al., 2005). Similarly, as has been illustrated in this paper, the conceptual and theoretical foundations for both PMPs and colored lenses are highly questionable. The range of symptoms of these disorders casts a broad net and opposing symptoms may be included (e.g., under- and over-sensitivity to sensory stimulation for sensory integration) or the conditions, such as eye fatigue, may be symptomatic of widely recognized visual disorders. Aligned with these purported conditions are assessment procedures that may be questionable or subjective, such as the Schilder test to establish the presence of persistent reflexes in assessment procedures for some PMPs, postrotary nystagmus in sensory integration (see Hoehn & Baumeister, 1994) or procedures used to select the colors of overlays or lenses. These assessment procedures are typically unique to the specific approach and do not have broader scientific acceptance.

In the absence of empirical research, proponents rely heavily on testimonials, anecdotal evidence and in-house unpublished research studies (see for example, DDAT, n.d.; Irlen Institute, n.d.). The presentation of anecdote and professional experience in the absence of scientific evidence (e.g., Evans et al., 1999; Irlen, 1991; Kimball, 1988; Pheloung, 1997) is undoubtedly a factor in the persistence of these approaches. Reliance on anecdotes and testimonies is recognized as one of the signs of pseudoscience (Park, 2003) and as a characteristic of controversial or fad treatments in special education (McWilliam, 1999). A clear belief that personal perceptions are inherently reliable, even when they are in conflict with objective evidence, is a key feature of pseudoscientific thinking (Sagan, 1997; Shermer, 1997). The power of testimonials as persuaders is recognized by the advertising industry (Cialdini, 2001). Newman (2003) provided some compelling accounts of the power of personal stories over hard scientific data in the field of medicine and concluded that a conscious effort is required to make decisions based on scientific evidence.

Implications for Educators

In the area of education, problems in forming considered judgments about the relative value of interventions may be exacerbated by teacher education programs. Postmodernist relativism is common, wherein all information is considered to simply reflect a particular perspective and anecdote and opinion is often given the same weighting as controlled empirical research. Teachers are encouraged through action research paradigms to appropriately view themselves as active researchers, but perhaps without understanding the very significant limitations of these methodologies. There is little doubt that teachers must be taught to be critical consumers of research but this necessarily involves understanding what research paradigms are appropriate to what sorts of questions as well as the limitations of these epistemologies. Mostert and Crockett (1999-2000) also argue for the inclusion of historical knowledge about failed or discredited interventions in teacher education. As we have seen, interventions like PMPs have a long history and keep reappearing with different names, different rationales but essentially the same practices.

In order to become informed consumers of research, educators need to be able to recognize some of the common characteristics of pseudoscience, as illustrated in the preceding discussion. Warning signs to the informed consumer may include interventions that are not consistent with verified theory, that use unique clinical constructs and assessment practices, and those that rely on anecdotes and testimonials, particularly in the absence of solid research evidence. Informed consumers should eschew unproven interventions or those with weak support in favor of those with more substantive evidence. They also have a professional responsibility to monitor developments in research, such that practices can be adjusted to reflect change in the evidence base. While it is likely to be a thankless task, informed consumers should also endeavor to educate others about the research base for interventions, including controversial ones, as well as the principles of scientific decision making.

Controversial practices are now widely advertised on the internet, often directly to parents and care-givers - another sign of questionable science, according to Park (2003) is by-passing peer review and going straight to the media. Despite lack of data supporting their efficacy, some controversial programs can involve substantial direct costs. For example, the Dore program was recently reported to cost around 1,900 pounds or approximately $3,700 US (Nicholls, 2006). Parents will attempt to search out the most compelling intervention for their child, but are likely to be uninformed about standards for scientific decision making and the past history of unproven interventions. Thus, professionals will undoubtedly encounter situations where parents elect to pursue ineffective or unproven interventions against advice and sometimes at great financial cost. One approach to this dilemma may be to agree with parents on objective expected outcomes, time frames and criteria for decisions about effectiveness. Smith et al. (2005) provide several excellent examples of how small n designs can be used to simply monitor controversial interventions and assist parents in objective and rational decision-making.

Educators will certainly find themselves in uncomfortable positions during meetings when practices they know are lacking in empirical evidence are advocated by other members of the Individualized Education Program (IEP) team. There is no single or simple response to such a dilemma, but educators must be prepared to meet the challenge with a professional demeanor. Some suggestions could include the following. First, if an educator learns through prior experience in meetings or just discussion that a professional member of the IEP team will be recommending a "controversial" practice, the educator could meet with the other team member prior to the IEP to discuss any concerns with the "controversial" practice. The discussion may lead to an agreement to collect data on child progress should the intervention be implemented, the adoption of a different intervention, or result in a stalemate. If the discussion results in a stalemate and the "controversial" practice is ultimately accepted by the IEP team, then there is a legal obligation to provide the service or intervention. However, as with all interventions, a careful monitoring should be conducted to determine the efficacy of the practice, and the IEP team may even agree to try a practice for a short period of time and review the data before deciding whether to continue with the intervention or not. Second, if a practice is clearly not supported by the research and, after consultation, the provider insists on recommending the practice at the meeting, the educator could request a meeting with the service provider and the administrator to discuss the procedure and determine whether the school administrator would support that recommendation during an IEP meeting. Third, an educator could also serve in a problem-solving capacity by identifying exactly what outcome is to be expected from implementing the specific practice, discuss the research findings, and suggest other alternatives that hold more promise in achieving the desired outcome. These recommendations certainly place a higher level of responsibility on the educator, who must know what may be recommended at and IEP meeting, whether the practice is supported by research, and if not, alternatives that would more likely achieve the desired outcome.

It is critical that educators become informed consumers of research, because school districts must comply with the IEP. Certainly, administrative support at an IEP meeting can help the district from agreeing to unnecessary programming, but part of that result requires that the administrator be educated about the controversial practices. Educators should be reminded that the law requires the IEP to provide a student with educational benefit, not maximize a student's potential. Giangreco (2006) provided useful guidelines for determining whether a particular related service was required. Since many of the "controversial" practices will be provided as related services, his suggestions are useful for determining what must be provided. First, some IEP team members assume that more service is better, but this really confuses quantity with quality. Too much of a service could actually be detrimental, because it could interfere with the student's participation in school activities with typically developing peers, result in stigmatization, and create undesired dependencies on the adults who provide the service or the service itself. Second, any service should only be as specialized as necessary, because this approach lends itself to drawing upon natural supports available to the student and also decreases student dependence on supports that are not typical of peers without disabilities. Finally, supports must be educationally relevant and necessary. To be relevant, a support must be directly linked to educational outcomes, that is, the goals and objectives on the IEP. If a service is educationally relevant, then the next question must be whether it is also necessary for the student to achieve the educational outcomes. If the student is receiving the desired benefit without the service, then the service would not be an educational necessity and the school would not have to provide it.

There is a pressing need for a very visible and accessible source of information on the internet about scientific evaluation of interventions in special education, similar to the Cochrane Collaboration in the area of medicine. Such a source could provide balanced information about effective and controversial interventions and educate consumers about scientific decision making procedures and the characteristics of controversial and unproven practices.

In conclusion, there has been a clear shift toward adoption of evidence-based practice in the area of education in recent years. Hopefully, more critical thinking and higher standards of evidence will see a decrease in the use of unproven and disproven interventions, such as those reviewed in this paper. In order for this to become a reality, professionals must ensure they are informed about evidence-based practice and take an active role in disseminating research to consumers.

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Keith J. Hyatt

Western Washington University Bellingham

Jennifer Stephenson and Mark Carter

Macquarie University

Sydney, Australia

Correspondence to Keith J. Hyatt, EdD, Chair, Department of Special Education, Western Washington University, Miller Hall 318a, Bellingham, WA 98225-9040; e-mail: keith.hyatt@wvvu.edu.
Table 1 Summary of Studies on Tinted Overlays

Author(s),       Subjects       Subject     Overlay     Eye
Year                          Ages/Grades     Type      Exam

Saint-John &  11 with         Mean age:     Not         No
White         reading         10-5 Grade:   specified
(1988)        disability and  6
              11 without
              reading
              disability

Blaskey et    30 self         Age: 9 to 51  Irlen       Yes
al. (1990)    referred for    years
              reading
              problems

O'Connor et   92 with         Age: 8-12     Not         No
al. (1990)    reading         years Grade:  Specified
              problems        2-6
              referred by
              teachers

Robinson &    44 referred to  Age: 9-1 to   Irlen       No
Conway        special         15-11 years
(1990)        education
              center

Martin et     20 with         Age: average  Irlen       No
al. (1993)    reading         12-6 for
              disability and  those with
              SSS, 20 with    learning
              reading         disability
              disability not  and 12-5 for
              SSS, 20         those
              without         without
              reading         Grade: 7
              disability

Fletcher &    22              Age: 10 to    Irlen       No
Martinez                      35 years
(1994)

Lopez et al.  39 from         Mean Age: No  Irlen       Yes
(1994)        previous study  disability
              who had been    11.1;
              referred by     reading
              special         problem
              education       11.6;
              teachers and    general
              self-referred   problems
                              10.7 Mean
                              Grade: No
                              disability
                              6.1; reading
                              problem 6.8;
                              general
                              problems
                              5.7

Robinson &    113 SSS         Age: SSS,     Irlen       No
Foreman       referred to     9.2 to 13.1;
(1999a)       special         non SSS, 9.4
              education       to 12.9
              center, 35
              controls
              without SSS
              identified by
              local schools

Robinson &    113 SSS         Age: SSS,     Irlen       No
Foreman       referred to     9.2 to 13.1;
(1999b)       special         non SSS, 9.4
              education       to 12.9
              center, 35
              controls
              without SSS
              identified by
              local schools

Whichard et   72 prison       Age: 16 to    Irlen       No
al. (2000)    volunteers      67

Christenson   16 with         Age: 10-6 to  Not         Yes
et al.        learning        13-11 Grade:  specified,
(2001)        disability      5 to 8        blue
              randomly                      filters
              selected from
              special
              school

Wilkins et    89 students in  Age: 8-6 to   Intuitive   No
al. (2001)    one school      10-6 Grade:
Study 1                       4 to 6

Wilkins et    378 students    Age: 8-2 to   Intuitive   No
al. (2001)    in one school   12-1
Study II

Bouldoukian   33 patients     Age: 1-10 to  Intuitive   Yes
et al.        attending       40
(2002)        Institute of
              Optometry

Scott et al.  153 students    Age: 10 to    Intuitive   Yes,
(2002) Study  in one school   12                        after
1                                                       study

Scott et al.  199 students    Age: 7 to     Intuitive   Yes,
(2002) Study  in one school   11                        after
II                                                      study

Northway      60 children     Age: Not      Intuitive   Yes
(2003)        who attended    specified
              an eye clinic   Grade: Not
              for 6 months    Specified

Author(s),         Measures         Findings related to academics
Year                                         and overlay

Saint-John &  1) Reading rate in   No difference on later
White                              identification or reading speed
(1988)

              2) Errors in letter
              identification

Blaskey et    1) Standard scores   No improvement in reading speed,
al. (1990)                         word recognition, or
                                   comprehension

              2) Scaled scores

              3) Reading speed

O'Connor et   1) Reading age       Improved reading rate, accuracy,
al. (1990)                         and comprehension when using
                                   preferred color lens

Robinson &    1) Reading age       Improvement in comprehension and
Conway                             accuracy but not rate
(1990)

Martin et     1) Reading age       No effect on accuracy,
al. (1993)                         comprehension, encoding

              2) Reading rate

Fletcher &    1) Comprehension     No effect on comprehension
Martinez      score
(1994)

Lopez et al.  1) Mean age          No relationship between SSS and
(1994)                             academic achievement

              2) Mean grade

              3) Percentile Score

Robinson &    1) Reading miscue    No impact
Foreman       errors
(1999a)

Robinson &    1) Reading age       Improvement in accuracy and
Foreman                            comprehension but not rate
(1999b)

Whichard et   1) questionnaire     55.6% reported improvement
al. (2000)

Christenson   1) Grade equivalent  No change in comprehension or
et al.                             reading rate
(2001)

              2) Time to complete
              test

Wilkins et    1) reading rate      Improved rate
al. (2001)
Study 1

Wilkins et    1) reading rate      Improved rate for chosen color
al. (2001)
Study II

Bouldoukian   1) reading rate      Improved rate for chosen color
et al.
(2002)

Scott et al.  1) reading rate      Improved rate for frequent use
(2002) Study
1

Scott et al.  1) reading rate      Improved
(2002) Study
II

Northway      1) reading rate      Improved for group choosing color,
(2003)                             but decreased for group who chose
                                   but didn't use overlay, and
                                   decreased for group who did not
                                   choose an overlay
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