By: Jeffrey Mitchell, Currey Ingram Academy
Published: August 2014
The focus of this FastStats is on the growth of LD schools within NAIS over the past 20 years.* Growth will be measured both absolutely and as a proportion of non-LD schools.
As a baseline, Figure 1 depicts the growth trend of schools that self-identify as non-LD schools. In 1993-1994, there were 862 non-LD schools in NAIS. In 2013-2014, there were 1,392. This represents a 161% increase. Figure 2 depicts the growth trend of schools that have self-identified as LD. In 1993-1994, there were 20 schools. By 2013-2014, there were 86 schools, representing a 430% increase.
Figure 1 and Figure 2 provide information on growth in absolute terms. To assess the more interesting question of whether NAIS LD schools have grown relative to non-LD schools over the past 20 years we can look at the proportion of schools that self-identify as LD versus those that do not, as Figure 3 depicts. In Figure 3, the reader will see that the proportion of LD schools, relative to non-LD schools, has climbed from about 0.02 (ratio of 1:50) to 0.06 (ratio of approximately 1:17). Another way to say this is that LD schools have grown three-fold as compared to non-LD schools over the past 20 years.
With this said, there is an anomaly in the data, especially evident in Figure 2 and Figure 3. The reader will notice a substantial jump in the number of schools self-identifying as LD during a three-year span from 2000-2003. Through a statistical lens, it is highly unlikely for this to occur, especially considering the trend during the years previous and the years subsequent. In speaking with the NAIS DASL staff, they confirm that a number of changes were made to the collection process during those years, which may account for this jump. Thus, it is quite possible that the proportion of LD schools within NAIS has not grown much in the past 20 years. In fact, if you just focus on the last 10 years of data you can see only minimal growth.
Regardless, an interesting question to ask is whether the proportion of LD schools, and the proportion of students represented, mirrors the population proportion of LD students. From a quick look at the data you would not draw that conclusion. For example, as noted, by 2013-2014 about 6% of NAIS schools identified themselves as LD. We also know that the median enrollment for a NAIS LD school is about 150 students and the median enrollment for all NAIS schools is very close to 400 students. Thus, although LD schools comprise about 6% of NAIS schools, the actual number of students is considerably less. Even the most conservative estimates of the overall population of students with learning differences would place the percentage much higher. For example, according to the National Center for Learning Disabilities (NCLD) State of Learning Disabilities report, about 5 percent of our nation’s school-age population has a formally identified learning difference, and an estimated 15% more of our students have unidentified and unaddressed learning and attention issues.
So, it would seem that students with learning differences might be underrepresented by NAIS schools. But before that conclusion is drawn, one must also consider the number of NAIS schools that have developed specialized programs to serve students with learning differences. The present data set does not account for that variation. Eyeballing the data confirms this to be the case. I recognize dozens of schools in the NAIS database that self-identified as non-LD but have a "learning center" that serves LD students.* I also know from personal experience that there has been a proliferation in the growth of "learning centers" within NAIS schools over the past 20 years. Thus, without question, more LD students are being served, than is represented by this analysis.
To conclude, there's no doubt that NAIS schools began serving a larger proportion of LD students in the past 20 years. Whether or not that proportion mirrors the population proportion is still an open question.
* The range of service varies dramatically from school to school.
From the editors: Watch the SAIS Lunch & Learn on SAIStv about cerebrodiversity, LD schools, and brain evolution. The short preview version is below. Click here for the full version.