According to many, the advent of the No Child Left Behind Act created an atmosphere across education of "teaching to the test." The impact of this has often meant significantly less flexibility for teachers in the classroom. This is being especially felt in science classrooms.
Increasingly, science education has been evolving toward argumentation, the practice of utilizing hands-on, practical experiments and critical thinking to arrive at results and comprehension. This is becoming a preferred standard in science curricula.
A recent survey conduced by researchers at Boston College's Lynch School of Education has revealed that teachers are encountering several barriers to the new standards. First, teaching to the test is limiting their ability to include instruction and practice in argumentation. Second, teachers in lower income schools and districts, especially, are finding that their students are not properly equipped to grasp and learn argumentation as well. This can be influenced by language barriers, for students where English is a second language, as well.
This is going to be a topic and practice area to watch.
Read more about the study: Perceptions of Student Ability, Testing Pressures Hinder Some Science Teachers