Designing, developing, and implementing a multi-year randomized control trial targeting what works in gifted education mathematics study is challenging, at best. In response to the United States Department of Education's Institute of Education Sciences request for proposal, we carefully constructed a mixed-methods study by assembling a diverse…

"Un Buen Comienzo" [A Good Start] was a professional development program implemented with prekindergarten and kindergarten teachers in Chilean public schools serving low-income families. In a randomized trial, the program showed moderate to large impacts on classroom quality but no impacts on targeted child outcomes. To unpack these…