The Common Core State Standards represent an exciting step forward for California, and for the nation as a whole, in supporting instruction that can better prepare students for college and career success. Concurrent with the transition to the new standards, the Smarter Balanced Assessment Consortium (SBAC), of which California is a governing member, is introducing a new, large-scale assessment system in 2015 that aligns with the Common Core. The SBAC assessments aim to capture student learning in a deeper and more authentic way than the state's previous assessment system--the California Standards Test (CST). This is not the first time California has transitioned to a new system of academic standards, instruction, and assessment. In particular, potential parallels exist between the SBAC assessments and the short-lived California Learning Assessment System (CLAS) of the early 1990s. As educators embrace the challenges associated with assessment of the Common Core, it is instructive to learn from the CLAS experience, both to build on its successes and to avoid the mistakes that led to its demise. In September 2012, the California Collaborative on District Reform released a brief that drew connections between assessment efforts tied to the Common Core and the CLAS. Reflecting on both the successes and failures of the CLAS, "Learning From the Past" identified four key lessons that should inform current activities related to Common Core implementation and assessment. The standards and assessments landscape has evolved dramatically since the 2012 brief was published, and education leaders have taken steps to avert some of the problems that undermined the CLAS. Nevertheless, key challenges remain. The goal of this brief is to chart the progress that has been made since the original brief was released in 2012, while also highlighting areas that remain in need of attention as the state continues to develop and implement student assessment systems around the Common Core. Doing so emphasizes the importance of assessment not solely as an external accountability tool, but as an essential component of implementing the Common Core. As the first administration of the SBAC assessments begins in spring 2015, the brief will be most effective if read as a set of considerations for improving the ways in which educators at all levels can respond to evidence of, and develop better approaches to, improving student learning. [Additional funding for the development of this brief was provided by the California Education Policy Fund, and the Silver Giving Foundation.]