In 2014, the Office of Child Development and Early Learning (OCDEL) in partnership with the Pennsylvania Department of Education's Office of Elementary and Secondary Education (OESE) began a phased deployment of the KEI. Cohort 1 implemented the KEI in the fall of 2014 and included Title I schools designated in Focus and Priority status under the Elementary and Secondary Education Act. Focus schools meet any one or more of the following criteria: Title I schools with a graduation rate below 60 percent; schools not otherwise designated as a Priority school, but falling in the lowest 10 percent of Title I schools (excluding bottom 5 percent); or test participation below 95 percent. Priority schools are the lowest 5 percent of Title I schools (based on aggregate math and reading PSSA or Keystone scores) or Title I schools receiving School Improvement Grant (SIG) funds. Focus and Priority schools were required to use the KEI as part of their planning process for instructional improvements. The KEI was open for voluntary use to any interested local education agency (LEA) or private kindergarten. Cohort 1 included 707 teachers who reported outcomes on approximately 16,000 children. These teachers represented 217 schools covering 21 districts. (author abstract)