Many States are implementing "get tough" sentencing reforms in juvenile justice. However, little attention has been given to evaluation issues identified by the adult justice sentencing literature as critical to assessments of efficacy. Analysis of juvenile determinate sentencing in Texas highlights such issues and demonstrates their relevance to assessment of other States' juvenile justice sentencing reforms. Many juvenile justice sentencing reforms have failed to produce realistic, appropriate, and valuable policies, resulting in costly cycling between policies that overemphasize incarceration and policies that overemphasize rehabilitation. Consequently, attention is diverted from the possibilities of sentencing, including alternative sanctions and uses of sentencing for purposes other than punishment. The article identifies failure to attend adequately to design, implementation, use, and assessment issues, including identification of potential unintended effects, as barriers to effective evaluation of reforms. Notes, references