Success in Algebra I often predicts whether or not a student will pursue higher levels of mathematics and science. However, many students enter algebra holding persistent misconceptions that are difficult to eliminate, thus, hindering their ability to succeed in algebra. One way to address these misconceptions is to implement worked-examples and self explanation prompts, which have been shown to improve students' conceptual knowledge. However this effect seems to be greater after a delay. The current study sought to explore such time-related effects on algebra conceptual knowledge. In a year-long random-assignment study, students either studied worked-examples and answered self-explanation prompts (n = 132) or solved typical isomorphic problems (n = 140). A three-way mixed ANCOVA (pre-algebra knowledge x condition x time) found a significant condition by time effect. The growth of algebra conceptual knowledge was greater for students studying worked-examples than for those solving typical problems.