1. Computational Application for Early Detection of Dyslexia in Pre-school Children Background  Aim of overall project  Aim of current phase  Phonological Deficit Hypothesis

2. The most commonly used tests in Ireland at present: The Dyslexia Screening Test (6.6 to 16.5 years) The Bangor Dyslexia Test (test not normed) Genetic Factor (Rack, 1999) Dyslexic Father Non- Dyslexic Father Dyslexic Mother Non- Dyslexic Mother Males0.4470.0500.3610.056 Females0.2060.0120.2070.015

3. Developing the test  Early/Intermediate/Late Consonants (Smit & Hand, 1997)  38 test items based on 19 phonemes  Selecting words and images  Pre-pilot the test – initial idea of validity and reliability  Technical aspects

5. Test Administration  8 pre-schools  104 children (+ 20 at pre-pilot stage)  Age range: 33 to 69 months  Locations: rural Wicklow to urban City Centre  20 questions per child  Mean score: 11.89; Mode: 11

6. Test Analysis

7. Point-Biserial Test  An item analysis test  Establishes a correlation between a right/wrong score a child receives in a given item and the total score that a child gets in the overall test  Ranges from +1 to –1  Varma: Point Biserial of at least.15

8. Test Analysis contd.  Low Point-Biserial Scores Removed:

9. Cronbach’s α  A split-half measure of the reliability of the test items Cronbach's Alpha Number of Items.830 17

10. Early/Intermediate/Late Consonants  Developmental Sequence as recognised by Smit&Hand (1997)  Early Consonants: Mean = 32  Intermediate Consonants: Mean = 33.8  Late Consonants: Mean = 32.58  No significant difference between groups

11. Location A 8.6763.670 Location B 11.0094.031 Location C 8.67123.312 Location D 8.83123.950 Location E 6.64142.706 Location F 10.07284.472 Location G 13.07142.999 Location H 7.6793.317 LocationMeanN Std. Deviation Total 9.501044.063 Significant variation in scores Parental interest? Phonological training? Age variation? Location

12. Age-Sensitive Test Mean Score Standard Deviation Group 18.05 3.268 Group 211.90 3.919 Group 312.35 4.499 Group 413.30 3.975 Group 513.54 3.833

13. Achievement  30 ‘good items’ in terms of reliability  Discriminates between children on their success at a phoneme-based test  Age sensitive  Correct pitch – format of test

14. Futher Development  Further pilot-test – More care in getting a representative sample – Try on a group who are known to have dyslexia  Further statistical analysis – Z-scores – Multiple Regression