How do we know whether PreK is worth the investment?

The best method to assess the true impact, and therefore the value of PreK over time is to measure the quality of PreK followed by the quality of Kindergarten, first, second, and even third grade.

Unfortunately, the studies that have this kind of data are few and far between.  Most studies skip over the intervening elementary years altogether and just link PreK attendance to third grade scores. Other studies attend to the lower elementary years but tend to use easy-to-collect data about teachers or schools as proxies for “quality” in those grades. These designs provide only a partial picture of how PreK really works.

Due to a partnership with DallasISD and Southern Methodist University, some unique data about classroom quality from PreK through 2nd grade has been collected. These data tell us about and student’s overall experience in the school environment and especially tell us about the interactions between teachers and students. These data covering everything from the teacher-student relationship, how instructional content is delivered and the overall climate of the classroom. This way of thinking about quality tells us much more about the actual learning environment and these data are, in turn, more directly related to learning outcomes.

These data go above and beyond what we typically know and provide some new information about the value of PreK when it is followed by excellence in the lower elementary grades.

The first round of results are in and are promising: not only are DallasISD early learning classrooms performing at high quality, students who are in high quality classrooms for multiple years in a row are likely to have the best outcomes.

First, attending a high quality PreK classroom increases the probability that a student will be ready for kindergarten; 62% of the PreK students who were in a high quality classroom were ready for kindergarten compared to 54% of students who were in a lower quality classroom. This is compared to 33% of students on track for kindergarten who did not attend DallasISD PreK at all.

This initial PreK experience, then, has cascading effects into the first years of elementary school. Consider this scenario: of the students who enter Kindergarten “ready” and then attend a kindergarten classroom that is also high quality, 83% are “on track” at the end of year. Compare this to students who entered kindergarten “not ready,” and had a lower quality kindergarten classroom. Only 20% of these students are “on track” at the end of kindergarten. Consider also, students who enter kindergarten “ready” but then have a lower quality kindergarten experience; 58% of these students are on track at the end of kindergarten.

So far, we have data that follows this pathway into first grade and the trends here are the same. In the best case scenario, students enter 1st grade “on track” (based on their end of kindergarten test scores). If these students are then in a high quality first grade classroom, 74% of them are on track by the end of 1st grade. However, if they are in a lower quality first grade, 67% are on track. In the worst case scenario, students are not on track when they enter first grade, and they are in a lower quality classroom. In this instance, only 12% of these students are on track.

The takeaways for early childhood education are that: yes, PreK matters. More than that, the quality of PreK matters because it sets the stage for what follows. Most importantly, multiple sequential years of high quality experiences add up to the best possible outcomes for students.

Click for PDF | doc.