Appropriate validity evidence is essential when interpreting scores from tests and instruments. In statistics education, the application of modern measurement theory is limited and not well integrated into research as support for instrument interpretation. The Validity Evidence for Measurement in Mathematics Education project is documenting validity evidence for mathematics and statistics education instruments through a structured literature review to create a searchable instrument database. This paper highlights the status of the work documenting validity evidence for statistics education instruments measuring constructs such as teacher knowledge and attitudes. Many “custom” single-study measures incorporated items from multiple validated instruments and/or added new items without providing evidence for the new instrument. Preliminary information about the types of validity claims and evidence identified from standardized coding is reported.