They should consult manuals on English composition. They should be able to construct substantial timelines, charts, graphs, tables, and maps, and append explanations in their own words. With such clear expectations, teachers can discern specific difficulties individual students are having and intervene early with extra instruction, so that the student's later schooling does not decline into repeated remediation and feelings of futility. Teachers and the parents of their students need to share clear and explicit mutual expectations for student homework and student conduct at school. Schools do not bring students to solid levels of accomplishment in a vacuum.
Every curriculum inevitably omits much important subject matter.
The challenge of curriculum design is not to cover everything worth studying. A Note on Textbooks. But it is equally clear, though not yet commonplace, that a well-written, balanced, and inclusive textbook gives students a frame within which to locate particular questions, topics, personalities, and episodes that teachers choose to stress. A textbook can serve as a time and story line students can carry with them and can be a useful reference. When used in conjunction with other sources, textbooks can help students to gain perspective, acquire knowledge, and refine their intellectual powers.