CDT and Firefly Information for 2026-2027

Classroom Diagnostic Tools (CDT) Windows 

• August 24, 2026 – June 11, 2027
  • Reading, Writing, and Mathematics (Grades 3-8)
  • Algebra I, Algebra II, Geometry, Biology, Composition, and Literature
• October 14, 2026 – June 11, 2027
  • Science (Grades 3-8) and Biology (opens later due to the standard setting process) 

Firefly Windows 

• October 5, 2026 – April 16, 2027
  • ELA and Mathematics (Grades 3-8); Science (Grades 5 and 8)
  • October 5, 2026 – May 7, 2027 Algebra I, Biology, and Literature 

Firefly Seasons

• Fall Season: October 5 – November 29
• Winter Season: November 30 – February 28
• Spring Season: March 1 – April 16/May 7 

Additional Firefly Notes:

• DRC has informed PDE that test tickets will not remain open for 48 hours. DACs or SACs with permissions can unlock test tickets which have locked overnight. If students are unable to finish the Firefly assessment in one class period, they can complete the assessment the next day. Students must complete Firefly in order for reports to be generated.
• Students answer questions across all reporting categories; we cannot divide these into smaller sections due to predictions.
• Students must complete the full assessment to receive a score.
• Starting in 2026-27, Science and Biology Individual Student Reports (ISRs) will include predictions. 

Educator Application: PSSA, Keystone Exams, Classroom Diagnostic Tools, and Firefly Assessment Committee Reviews

The Pennsylvania Department of Education (PDE) conducts various meetings in support of the Pennsylvania System of School Assessment (PSSA), the Keystone Exams, Classroom Diagnostic Tool (CDT), and Firefly. The attendees for these meetings are Pennsylvania educators. Pennsylvania educators have been involved in the development of the PSSAs, Keystone Exams, CDT, and Firefly since their inception. PDE relies on educators to review items for alignment with the assessment anchor content standards, level of difficulty, bias, clarity, grade appropriateness, and a host of other indicators.

If you are interested in serving on a review committee, submit an application!