Dyslexia Index as a discriminator

• Plenty of data analysis was conducted both in MS Excel and in SPSS to establish sensible, working boundary conditions that would enable the Dyslexia Index metric to fulfil its purpose as a discriminator in identifying the principal research subgroups.
  
  
• Eventually, a boundary value of Dx = 592.5 was set, above which a respondent was considered to be presenting a dyslexia-like profile.
  
  
• In the research subgroup of questionnaire respondents who declared that their dyslexia has been identified, the substantial majority presented Dx > 592.5, suggesting that the Dyslexia Index metric successfully concurred with identifying existing dyslexia.
  
  
• A lower level of Dx = 400 was also set, beneath which a respondent was considered as highly unlikely to be presenting a dyslexic profile. In the dyslexic group, only 2 respondents presented Dx < 400, whereas in the research group of students with no declared dyslexia, nearly 50% presented Dx < 400.
  
  
• It is notable that the range of Dyslexia Index values is much wider for students with no declared dyslexia than for existing dyslexic students, suggesting that there is indeed a proportion of students with unreported dyslexia or dyslexia-like profiles.
  
  
• It is also notable that both groups - dyslexic students and non-dyslexic students - contained a sizeable number who presented a Dyslexia Index within range that had the two boundary values as the limits, that is: 400 < Dx < 592.5. This appears to be indicating a 'grey area' of students who are partially dyslexic or who are presenting just some of the characteristics typically associated with dyslexia. This is to be investigated in due course.