A child's development can be measured through developmental milestones; "significant skills which are developed in and around certain ages as part of the usual or expected pattern of development" (Kamen 2011). Sequence of development refers to the order in which these milestones are met. Sequence of development refers to the fact that development usually follows the same basic pattern, that is skills are usually acquired in the same order. For example, babies' development will usually follow the same broad sequence as follows: sits without support, crawls/bum shuffles, pulls to stand, cruises around furniture, walks.
Rate of development
Rate of development refers to the speed at which the child's development takes place and the speed at which these developmental milestones are met.
Importance of the difference between sequence and rate of development
It is important to understand the difference between the sequence of development and rate of development because, whilst the sequence usually remains the same, the rate at which many milestones are achieved can vary greatly. The rate at which some milestones are achieved is more variable than others.
The rate at which development occurs is dependent on a myriad of factors, both personal to the child (health, learning difficulties, behaviour, motivation) and external (family, community, educational background ).
Following on from the above example, two children following the same sequence of development outlined above may meet the relevant milestones at different ages. Child A may sit at 6 months, crawl at 7 months, cruise at 9 months and walk unaided before 12 months. Child B may sit at 8 months, crawl at 12 months, cruise at 15 months and walk unaided at 18 months. The sequence of development is the same for each child, but it is clear that the rate of development is different.
It is important to understand that two children may develop at completely...