This document discusses different approaches to teaching skills, including: - The UK curriculum says skills should be taught through substantive science content. - US science standards integrate skills with content in "learning performances" that construct explanations based on evidence. - Research finds that skills should be broken into components, taught individually with modeling and focused practice, and integrated across topics with lots of practice. - In practice, skills often lack explicit teaching and are marginalized in curriculum time due to an "expert blind spot".