The authors of this volume's stimulus papers have taken on the challenge of developing measures of teachers' mathematical knowledge for teaching (MKT). This task involves multiple decisions and considerations, including: (1) How does one specify the body of knowledge being assessed? What warrants are offered for those choices?; (2) How does one…

The last century was marked by dazzling changes in many areas, such as technology and communications. Predictions into the second century of testing are seemingly difficult in such a context. Yet, looking back to the turn of the last century, Kirkpatrick (1900), in his American Psychological Association presidential address, presented fundamental…