Valerie Strauss is a reporter and op-ed writer for the Washington Post. This opinion piece appeared onMay 6, 2021.

Now that the philanthropic Bill and Melinda Gates have announced they are divorcing after 27 years of marriage, let’s look at the controversial investments they made together to reform K-12 public education — and how well those worked out.

Together, the two have been among the most generous philanthropists on the planet, spending more over the past few decades on global health than many countries do and more on U.S. education reform than any of the other wealthy Americans who have tried to impact K-12 education with their personal fortunes.The Bill & Melinda Gates Foundation has spent billions of dollars on numerous education projections — such as creating small high schools, writing and implementing the Common Core State Standards, evaluating teachers by standardized test scores — and the…