The Early Development Instrument (EDI)

Early Development Instrument

What is EDI?

The Early Development Instrument (EDI) is a checklist completed by Senior Kindergarten teachers that measures a child’s developmental health as they enter Grade 1. The EDI tool is not used as a diagnostic tool for individual children, nor does it measure a school’s performance. Rather, the data is mapped by postal codes to provide information about groups of children within neighbourhoods and communities.

EDI results allow communities to:

  • Identify neighbourhoods where there are strengths and vulnerabilities
  • Monitor populations over time
  • Predict how children will do in elementary school

The results obtained from the EDI can help local community planning groups and service providers make evidenceā€based decisions on programming for the early years.

See the video, "The EDI and Early Years" (YouTube), highlighting the Early Development Instrument and the importance of the early years.

The Five Domains of Child Development

The Offord Centre for Child Studies (McMaster University, Hamilton, Ontario) designed the EDI so that teachers could observe and "rate" competencies and behaviours of children within 5 domains of child development:
  • Physical Health and Well-Being
  • Social Knowledge and Competence
  • Emotional Health and Maturity
  • Language and Cognitive Development
  • Communication Skills and General Knowledge

These domains are further classified into sub-domains.

EDI Scores and Vulnerability

EDI Scores

On track versus not on track percentages
The EDI outcomes for each of the 5 developmental areas or "domains" are divided into categories representing the highest scores to the lowest scores in the community (distribution of scores). The range of scores is then divided into four groups, each consisting of scores of a quarter or one fourth or 25 percent of the children in the site. These groups are called percentiles:

On track (Top)

  • The total group of children who score in the best 25th percentile of the site's distribution

On track (Middle)

  • The total group of children who score between the 75th and 25th percentiles of the site's distribution

Not on track (At Risk)

  • The total group of children who score between the lowest 10th and 25th percentile of the site's distribution

Not on track (Vulnerable)

  • The total group of children who score below the lowest 10th percentile of the site's distribution

Multiple Challenge Index (MCI)

  • If a child scores below expectations on 9 or more of these sub-domains, he/she is considered to have multiple challenges.

For additional definitions and explanations, please view the EDI Factsheet and the FAQs and Glossary.


A research study, Starting Early: Teaching, Learning and Assessment released in June 2013 has linked EDI results with Education Quality and Accountability Office (EQAO) scores in Grade 3. It was found that students with low EDI scores, i.e. those in the vulnerable or at-risk groups are much less likely to achieve the provincial standard on the Grade 3 EQAO reading, writing and mathematics assessment than those with high EDI scores, i.e. those students deemed to be ready or very ready in kindergarten.

For more information about EQAO visit