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Classifying Open Educational Resources and Affordable Materials

Definitions and explanations about OER and affordable course materials, including key differences and similarities.

Published onOct 17, 2022
Classifying Open Educational Resources and Affordable Materials

Definition of OER

Open educational resources are defined as

“teaching, learning, and research resources that are free of cost and access barriers, and which also carry legal permission for open use. Generally, this permission is granted by the use of an open license (for example, Creative Commons licenses) which allows anyone to freely use, adapt, and share the resource—anytime, anywhere.”1

This definition has two key aspects: the freedom to access open content and the freedom to adapt and reuse the content in other contexts. The right to reuse OER was epitomized in Wiley’s concept of the 5 Rs,2 which include the right to revise, remix, reuse, redistribute, and retain copies of content that are shared openly. The openness of OER through the 5 Rs is the main aspect that sets them apart from other freely available content online.

Definitions of affordable course materials

We define affordable course materials as

“Educational materials that are deemed low-cost or otherwise attainable for low-income learners. The specific price of affordable materials differs greatly from one institution to another, usually from $40 to $60.”

This designation for what counts as low cost may come from a variety of places, including student surveys, institutional committees, or economic factors such as minimum wage, as in this example from Louisiana: 

“Affordable educational resource” or “AER”, means a single or collection of required educational resources that may be offered at no or low cost to a student through a postsecondary education institution or an affiliated college bookstore at a pre-sales tax cost to a student that does not exceed an amount equal to four times the federal minimum wage. AER includes copyright protected material purchased by a library and provided to a student at no cost.”3

In addition to comprising a wide range of definitions and determining factors, affordable course materials can also be supported through many different business models.

  • One-time purchases: In which a physical or electronic material is purchased for perpetual use. The buyer can choose to sell or discard the material at their discretion.

  • Rentals: Materials which are able to be accessed for a limited time. This may include print rentals, which must be returned by a specific date, or electronic rentals, which disappear after a certain period of time has elapsed. 

  • Inclusive access programs: Electronic deals in which publishers negotiate for an entire course (or even college) to opt all students into an online rental for course materials at a lower cost than would otherwise be “possible.”

  • Subscription or fee-based models: Materials that can be accessed by users after they authenticate or provide other proof that they are authorized to access the content. This may include library-licensed materials or things like Waymaker, which may require a student-facing fee for coverage or be sponsored by a department.

  • Free but not open materials: Materials which can be accessed freely online but which do not include permissions for reuse and adaptation. Most websites fall into this category.

  • Free and open materials: Materials which can be accessed freely online and which include permissions for reuse and adaptation. OER fall into this category.

Key differences and similarities

As we previously discussed, OER fall under the category of affordable learning materials, though not all affordable learning materials are OER. You can think of it like a Venn diagram where the broadest level of content is “educational materials,” and only after you define and filter these materials for content that is affordable, free to access, and openly licensed with remix permissions do you reach the level where OER reside.

Nesting boxes of educational material types, from "educational materials" at the top level to "free to remix and adapt OER" at the most specific level.

Figure representing the definitional intersections of these material types.

License (with both affordable and OER materials)

Aside from cost, one of the key differences between OER and other affordable course materials is their license. If a material is only available under all-rights-reserved copyright, it cannot be considered an OER. Similarly, if a piece of content is available under a Creative Commons license that does not allow users to remix the material, it would also not be considered an OER. Instead, the material might be considered “open access” or “free but not open,” depending on the context of its publication. The right to remix and adapt material is a crucial right for OER, as this is what allows instructors to adapt materials to fit their pedagogical needs.

A table that explains different material types’ relation to open licensing is provided below:

Material Type

Openly Licensed

Freely Available


Open educational resources




Free online resources under all rights reserved copyright




Materials available through your library




Open access articles and monographs




Table 1 is from The OER Starter Kit by Abbey Elder, licensed CC BY 4.0.

For a more simplified discussion of the unique characteristics of OER, affordable educational materials, and open access content see the graphics below:

Graphic that reads Open Educational Resources. Freely available to read and share online. Openly licensed to facilitate "no fuss" adaptation, remixing, and redistribution, including in print.
Graphic that reads Affordable Educational Materials. Materials that are free or low-cost (typically under $50). The focus is on cost to read, not adaptation. Open licensing is not required. Includes low-cost textbooks, rentals, library materials, and free content such as OER.
Graphic that reads Open Access Content. Research and scholarly content that is published free to read without barriers. Open licenses used vary, and may include CC BY NC ND (no adapt or remix). Content may be shared through an OA publisher or a repository.

These graphics were adapted from original graphics by Robert Ladd at NSCC’s Teaching Center, who graciously gave the authors permission to use his work.

Cost of online and print editions

Affordable course materials range in cost from free to $50 for both print and online materials, although the exact price cutoff may vary from institution to institution. Online materials that fall under this category include journal articles available through a library, ebook rentals, and select materials available through publisher-packaged deals such as inclusive access programs. Physical materials that fall under the “affordable” umbrella include printed course packets, textbooks on reserve in a library, and other low-cost print materials such as used books. 

Conversely, OER are always free to access online since they don’t reside behind paywalls. While you can print OER legally thanks to their open licenses, printing does come with a cost for materials. The cost of printing varies depending on the vendor and process (e.g. black and white versus color), but typically costs less than $40 for a black and white textbook.

Variety of type, format, and length of time available

Because OER can be any openly licensed and freely available educational resources, they may include videos, lesson plans, lab books, and whole courses. This variety of type is also present in affordable educational materials. Materials that fall under this category include course packets (collections of images and readings which replace or supplement a textbook), blog posts, documentaries and films provided through an institution’s library, homework platforms, ebook rentals, and digital textbooks like those provided through Inclusive Access programs.

However, the long-term availability of open versus affordable course materials does vastly differ, from the point of purchase and into lifelong access. Print textbooks are less likely to be available at a low cost, and the used book market–where affordable print copies are most likely to be found– has been dwindling year over year as publishers focus on the electronic textbook market.4 For workbooks, the print market is particularly difficult to navigate, as students cannot easily retain the exercises and refer back to the work they’ve completed due to the transitory nature of these materials.

For online materials, ebook rentals and inclusive access programs offer access to course materials only for a limited time, after which point students must renew their access through an additional fee or lose access. These programs run counterproductive to lifelong learning and depending on their implementation, they may not prioritize student choice, privacy, or their agency to opt out of a purchase. 

The table below provides an overview of how these kinds of student-centered considerations can affect data sharing and perpetual access when it comes to common learning material options:

Graphic of a table looking at characteristics of learning material options, looking at whether materials are openly licensed, free from cost, free from personal data sharing, available in perpetuity, and available when a course starts.

This is not to say that OER are perfect and avoid all of these concerns, however. While you can legally download, reuse, adapt, and share copies of OER, the technical ability to do this work varies based on the content, its format, and the work that the author/publisher of the OER put into making it easy to reuse.5

A more holistic way of approaching this topic might be to compare the pros and cons of each material type (See Affordable Course Materials: Pros and Cons). For example, OER are always free to access, but the level and type of materials available varies greatly by discipline. In contrast, there are a wide variety of materials available through traditional commercial providers; however, these materials are often more difficult to adapt and require student or institutional investments to access.

In the end, all course materials have pros and cons, and the low cost of one does not exempt it from critique. Even courses with no material costs will likely contain a mix of open and closed content, leveraging both copyrighted materials available for free online and OER. Keeping in mind the unique benefits and challenges of these diverse materials can help you be a better advocate while supporting instructors to make the decision that is right for their course.

The header image for this Pub was adapted from “Shape Sorter” by Ella’s Dad on Flickr, licensed CC BY 2.0.

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