Learning progressions describe the steps involved in learning a particular complex skill. With some skills, the sequence of steps in a learning progression matches the sequence of mental processes needed for learning the skill. Learning to read and learning to perform mathematical calculations typically depend on careful sequencing. For example, a child needs to be proficient with phonemic awareness skills in order to be able to learn to decode phonetically. In math, learning to add needs to occur before a child can learn to multiply. These types of learning progressions might be called natural.
Sometimes educators also use the term learning progression to refer to any sequence of skills in a curriculum—not just those in which the sequence actually matches the steps needed to learn something. For instance, in social studies, American History might precede World History—but there is nothing in how we learn social studies that requires the one to come before the other. World History could just as easily precede American History. The sequence is, therefore, arbitrary.
Drawing on learning progressions (both natural and arbitrary ones), academic (or educational or content) standards describe what students should know and be able to do at each grade level leading up to high school graduation. The standards are the road map that educators follow as they teach their students.
Within a reading curriculum, learning progressions guide the curriculum’s scope (the “what” of learning) and sequence (the “which comes before what” of learning). When these curricula are grounded in the science of reading, their scope and sequence follow the natural sequence of steps involved in learning to read (e.g., phonemic awareness precedes phonics). Even when a curriculum is guided by the science of reading, however, its scope and sequence will be arbitrary in some ways. For example, explicit instruction in vocabulary will be based more on the individual needs of students than on an invariable set of steps. And literary analysis (e.g., learning about plot and characterization) does not follow a natural sequence.