If we believe good teaching should be valued more, we must learn how to evaluate it in ways that are publicly credible and professionally acceptable. Highly accomplished teaching draws on a complex blending of intellectual, technical, professional and personal capabilities.  Methods for assessing teacher performance need to reflect that complexity. The Portfolio Project is one of several ACER initiatives to develop valid methods for providing teachers with useful feedback, promoting professional learning and assessing their performance for purposes such as professional recognition and certification. Others include classroom observation, student perception surveys and assessment of professional knowledge. So far the ACER Portfolio Project Team has developed four tasks for generalist primary teachers and four for secondary science teachers. These tasks currently being field tested for the feasibility and credibility by practicing teachers.