Linking Evidence to Practice: Data Systems That Can Be Used to Improve Teaching and Learning Dan Goldhaber University of Washington and Urban Institute

2 Why Focus on Teachers? Teacher quality is the key to school success –Its impact is far larger than any other quantifiable schooling input (Coleman et al., 1966; Goldhaber, 2002; Rivkin et al., 2005) The estimated impact of teacher quality is large –It can explain more than a full grade-level equivalent in test performance (Hanushek, 1992)

3 Central Thesis K-12 education should be a continuous learning system, but it’s not –Key missing ingredients: data and analysis capacity Combined, these could be used to convincingly answer key policy questions In the absence of such a system decisions are made based on fads, institutional inertia, and politics

4 We’ve Actually Learned A Lot from Longitudinal Data in Select States Data Quality Campaign specifies key characteristics of state longitudinal systems The most important schooling research is going on based on data from a select number of states (see CALDER) Three lessons about schooling: –Teacher quality is the most important factor over which schools have control –Teachers effectiveness varies considerably –Teacher credentials are weak, at best, predictors of teacher quality

5 Teacher Quality Appears to be Primarily “Unobservable” back

6 Experience Levels 1st year mean-2nd year mean: 0.059** sd 2st year mean-3nd year plus mean: 0.026* sd 1st year mean-2nd year mean: 0.050* sd 2st year mean-3nd year plus mean: 0.039** sd back degrees NBCTs backdegreesNBCTs

7 Degree Levels Difference in means:.005 sdDifference in means:.014 sd back experience NBCTs backexperienceNBCTs

8 NBPTS Certification Status Difference in means: 0.19** sd of teacher quality back degrees experience backdegreesexperience

9 Bad Data = Limited or Bad Research + Wrong Answers In the absence of this linkage one cannot assess most teacher-based policies –Teachers and students are not randomly matched to schools or classrooms Miss impacts on subgroups Aggregation bias Matching process produces erroneous estimates of the impact of teacher credentials

10 Hurdles Associated with Student- Teacher Linkages FERPA Cost Politics

11 Conclusions We could learn a great deal more about schooling than we do based on the data that are already collected –Data systems need to be able to talk with one another We can’t afford not to create data systems that allow us to emprical test the efficacy of schooling policies and practices –The student achievement costs of not having K-12 education be a learning system are not readily apparent, but they are real