Standardized tests are returning to the nation’s schools, but with lower stakes and an option to opt out for many families. States are adopting a patchwork of testing plans after the Biden administration offered new flexibility during the pandemic. Some are shortening tests or delaying them, and many are lowering the stakes. Officials in some states say tests are the last thing students need right now, but the Biden administration ordered tests to resume to assess the impact of the pandemic. Some testing supporters are frustrated by the scattered approach, saying it will make it impossible to get a clear national picture of learning setbacks.