Office of Child Development and Early Learning (OCDEL) Research

This study takes the first step toward creating a vertical
scale for WSS using an alternative method, a common-person design.

During the 2010–2011 year, each participating child was
rated on two Developmental Checklists (P3 and P4) at
each of two rating periods. Children who were age 3 at the
beginning of the school year were rated on both checklists
in February and May, and children who started the school
year at age 4 were rated on both forms in October and
February.

The results of this linking study verified that for a given
child at a particular point in time, ratings on the WSS
P3 Developmental Checklist tend to be higher than
those on the P4 level. This result was expected because
the Developmental Guidelines require a higher level of
performance to obtain a Proficient or In Process rating on
P4 than on P3.

When there is a need to track a child’s WSS results
over a period of time during which both the P3 and P4
Developmental Checklists have been completed, the user
can accomplish this by converting the raw scores on one
of the levels to the corresponding raw scores on the other
level. Either level may serve as the reference level (the one
to which scores are converted).