Hi John. In our OER Guidance for Schools, we identify the following benefits (in G1: Open Education and the Schools Sector):

Why use OER in schools?

Open Educational Resources enjoy a range of social, educational and financial benefits. OER can
support schools and school staff in increasing access, fostering collaboration and ensuring value for
money.

By openly licensing learning materials, schools can provide additional value — making publicly
funded works available for public benefit, through open and free exchange.
Education benefits from good resources, and reusing existing OER frees up time that can be spent
on other aspects of teaching and learning.

At the school level, use of OER (instead of paid-for resources) can help reduce costs, and get the
most out of existing budgets. Schools can benefit by increasing their capacity through connecting
to OER networks of educators and expertise. OER (and Creative Commons licences) provide a
framework on the basis of which schools can collaborate and share flexible learning materials (such
as worksheets, course or textbooks) alongside innovative and effective practice. Use of OER enables
schools to work together. Releasing resources under open licences promotes the often outstanding
work that staff and schools are doing.

From an educator’s perspective, OER use and creation can bring educators together and support
school staff in achieving shared goals. Through sharing resources in common areas of interest,
working with OER can help develop school communities. Being able to draw on multiple sources,
new approaches and expertise invigorates teaching and can increase quality.

OER increases the pool of resources available for activities in the classroom. This can support
differentiation more easily, and increase the variety of classroom activities, as well as help provide
extension tasks.

OER also provide a range of benefits from a student perspective. They can increase the
availability of free-to-access resources and supplementary materials available to learners. They
can support independent and informal learning, providing educationally focused materials in areas
young people are interested in learning more about, which might not be covered by the school
curriculum, or might be taught on courses they aren’t able to take. OER also make resources
available to learners globally who may not be as well supported as UK learners.

In more quantitative terms, you'll want to check out the OER Hub's OER Impact maps: http://oerresearchhub.org/evidence/oer-impact/

Best wishes, Josie