Utah Math Visions
ASSISTments contains many problems from Utah Math Vision Project for high school (http://www.mathematicsvisionproject.org). The content is marked as being released under a Creative Commons License.
All Creative Commons licenses require that people who redistribute such content need to do 4 things: 1) give an attribution on who the authors are/where it came from, 2) republish a link to the exact Creative Commons license that it came from, so others will know the license to cite, 3) provide a disclaimer that the original authors do not endorse WPI's use (or our changes), and finally 4) to state if we know if the material is copyrighted. We will now do these 4 steps.
First, for attribution, this material comes from a group that calls themselves the Math Vision Project. See mathematicsvisionproject.org. The authors are listed as Scott Hendrickson, Joleigh Honey, Barbara Kuehl, Travis Lemon, and Janet Sutorius.
Second, the exact license. There is some discrepancy between pages at the site. Some say CC-BY-4.0, while others claim CC-BY-NC-SA-4.0. WPI does not care which, as we are not using these for commercial purposes. For instance https://www.mathematicsvisionproject.org/secondary-mathematics-ii.html has a CC-BY-NC-SA symbol, but this page (https://www.mathematicsvisionproject.org/uploads/1/1/6/3/11636986/m2_mod1_se_22017f.pdf) says CC-BY-4.0.
Third, that page also claims copyright, to quote, is "© 2017 Mathematics Vision Project Original work © 2013 in partnership with the Utah State Office of Education."
Last, we provide the disclaimer that the Math Vision Project in no way endorses our use. All errors on our website are WPI's fault. And to be clear, we are making small modifications to make sure the questions can be answered by computer. For instance, we have tried our best to put the same material into ASSISTments, but errors happen. To give an example, we had a copy-paste error the other day reported where we copied the "1/2" symbol but it pasted as "12." We have corrected the errors when we have been informed about them. Also, we have to modify the content to make it gradeable by computer. For instance, we sometimes have to specify how many digits to round your answer to. But we have tried to stay as consistent with the author's intent.
We would like to thank the authors for releasing this free resource.