​Narrative 10-1 -Daycare Center - Part I

Multiple Choice

​Narrative 10-1 -Daycare Center - Part I
Ken studies literacy and is particularly concerned about children who lag in reading readiness.He has developed a reading readiness program that can easily be implemented by day care providers in group settings,and has selected two day cares in demographically similar neighborhoods.He starts by giving a reading readiness to all of the three- and four-year-olds in both day care centers. 
Figure TB 10-11

-Ken decides to implement his intervention at one daycare but not the other,and after the intervention is complete,he administers the reading readiness test again to both groups of children.His results are shown in the accompanying figure.This figure most suggests the existence of a(n) ____ threat.

A) instrumentation
B) testing
C) selection
D) diffusion