This practice sets high expectations for students, and we know that getting students to construct explanations is challenging. This practice also provides opportunities for students to engage in the cognitive work necessary to doing science, and allows us to really "see" what they are understanding.

To help our students be successful in this practice, we need to understand what the challenges are, and intentionally plan scaffolds, strategies, etc.

Challenges for Students:

Differentiating between evidence and reasoning (evidence in science can be different from evidence in ELA/social studies classes, and the idea of "reasoning" in science may be new to students)
Organizing information (students will often be working with evidence and science concepts gathered over many different lessons, and organizing all the information in a way that allows them to make connections is often difficult for students)

Challenges for Teachers:

Getting the right question (the wrong question can make writing an explanation really difficult, if not impossible!)
Scaffolding so that students can collect needed evidence
Scaffolding so that students can understand reasoning, and differentiate between evidence and reasoning
Time (as always) - students need time to revise their explanations (this also means time has been spent to provide feedback for the revisions), grading explanations can be time consuming