Milestone vs Average - What's the Difference?

Many times when a parent wants to know if their child is meeting the developmental norms, they will either ask their pediatrician, ask other parents, or search it on the web. However, the information obtained may differ which leads to confusion on the parent's part when they are considering whether their child needs therapy or not.

Now a distinction needs to be made between "milestone" and "average". When a child is meeting a milestone, oftentimes it is defined as an act that 90% of children of that age can accomplish. However, an average is an act that 50% of children of that age can do. This distinction becomes significant when an "average" child at 2 years old can speak anywhere from 200-400 words and start putting 2 word phrases together. However, the CDC states that the milestone for a child of 2.5 years (30 months) is 50 words. Or at 3 years old, a milestone for speech is 250 words, but the average for a 3 year old is over 1000 words.

If you want to know an insider SLP truth...if a monolingual child is not speaking around 50 words at 18 months, it kind of raises "red flags" for speech language pathologists. You can consider a milestone as a minimum that a child needs to meet, in order to be considered developing within normal limits. However, this minimum falls very low on the scale of what is considered "normal".

Honestly, if the child is barely meeting a milestone...it's too costly for the child to "wait and see". Yes, eventually the child should reach the milestone. But with each passing month (or year), the gap widens as to what an "average" child can do and what a "milestone" child can do. It won't hurt to consult a speech language pathologist and nip that in the bud. At the end of the day, as a parent, you know your child best. So, trust your gut and follow that. It's usually right.