The MET Extension project, funded by the Bill & Melinda Gates Foundation, is cataloguing and making accessible to researchers a large collection of videos of mathematics and English language arts teaching in U.S. classrooms.

The collection will include approximately 15,000 unedited videos of classroom teaching collected from more than three hundred teachers in grades four through nine during the 2011-2012 and 2012-2013 academic years. It will be a valuable resource for individuals and organizations working in education-related fields, including practitioners, teacher education institutions, professional development providers, educational materials developers, and researchers. Videos are available to researchers through the Inter-university Consortium for Political and Social Research (ICPSR). Individuals and groups interested in educational uses other than research will be able to view 1,500 of the videos through the Teaching and Learning Exploratory at the University of Michigan. Patrons of the digital archive can search and browse the collection in flexible ways, create “virtual clips” to show others, produce their own playlists, tags, and comments, and
also help to improve the collection over time through their feedback and shared work.

How Videos Are Accumulated and Prepared for the Collection

The teachers participating in this project started recording lessons in January 2012. They are using specially designed camera units that allow for capture of the classroom, the board, and high-quality audio from both the teacher and the students. Researchers at Westat worked with districts, schools, and teachers to collect the classroom observation data and to create video files that can be viewed and used online. Videos are “tagged” with labels that enable users to easily search and find relevant examples of teaching practice to match their interests and needs. Researchers at TeachingWorks developed the tagging scheme based on high-leverage teaching practices and the Common Core State Standards, with input from teacher training institutions and other organizations.

Overview of Tag Scheme

TeachingWorks has developed a set of tags for use in labeling and cataloguing the MET Extension video collection. These tags enable users to search the collection easily and to locate videos with specific content or characteristics. There are two kinds of tags:

  1. Instructional practices tags, or tags related to specific instructional practices and strategies that are being used in a lesson, such as whole-class discussions, small group work, and particular classroom management practices. Many of these tags correspond to the TeachingWorks high-leverage practices, which are instructional practices that are fundamental to competent teaching.
  2. Common Core State Standards (CCSS) tags, or tags related to the Common Core State Standards in English language arts or mathematics that are being addressed in the instruction in the video. Not included are tags that would apply only at grades K- 1 or above grade 9 because the MET Extension videos are from fourth through ninth grade classrooms.

The tags are applied to video at five-minute intervals. In any given five-minute segment, multiple tags may be applied. Tags are not mutually exclusive within a given time segment, but the descriptions of tags were written so that the application of any given tag didn’t require the application of a second tag. For more information on the tag scheme development process, click here.

What the Tags Are and What They Are Not

The tags based on the Common Core State Standards differ from the actual standards. The CCSS comprise a set of learning goals for K-12 students. In contrast, the tags describe what students and teachers are working on together in the classroom in relation to those learning goals. They do not suggest that students have learned specific topics or practices.

The tags are also not evaluative. That is, they do not indicate the quality or integrity with which a specific aspect of content is being taught or learned. They are descriptive markers that indicate that a particular aspect of mathematics or English language arts is being worked on by the class, by either teachers or students.

The tags map to the CCSS but the tags are not always in one-to-one correspondence with the Common Core. In some cases, the items from the CCSS were reorganized to make better or more usable grain-sized tags, particularly in mathematics. For example, one of the mathematical practices items that is part of the Common Core is, “Students make sense of problems and persevere in solving them.” For the purposes of the MET Extension project, this practice was divided into two tags, one for making sense of and interpreting problems and the other for work on persisting with difficult problems. This allows the collection to be labeled more precisely.

If you have questions about the MET Extension project, please contact To view the tag scheme booklet click here or on the booklet below.

METX Video Tags