Knowing when, what, and how to cite can be tricky. In general, there are four legal considerations:
1) The purpose of the use
2) The nature of the copyrighted work
3) The amount of work used
4) The market effect of the use
While it is often assumed that any educational use is fair game that is inaccurate. Teachers and students are more protected but it is not a blanket protection. Work used entirely in a classroom and not claimed as one’s own is generally protected. Facts are generally protected. Works that are creative require permission and there is more leeway if only a small part of the work is used and the work is not placed on the internet or is not used for making money through workshops or other endeavors (summarized from: https://owl.english.purdue.edu/owl/resource/731/01/).
This means that in general, AMTA curriculum can be used in your individual classrooms, but not published to the web, unless it is password protected (answer keys should never be published). If you adapt AMTA curriculum, credit should be given to the original source unless the adaptation is so extensive that it would not be possible to identify that source. A general rule of thumb is that if you would acknowledge someone in a face-to-face meeting for the contribution, it is common courtesy to recognize that person or organization in writing on the product. Thus, pictures, graphs, scenarios, worksheets, labs, should all cite the original source. If these are heavily adapted, then adding in “adapted from” recognizes both your work and the work of the original designers.
One non-legal way to think about this is that many people, either individuals or groups, spent a lot of time designing the materials, the citation is an acknowledgement that expresses your gratitude for their investment. Over attribution is rarely a problem. So when in doubt, cite – on the worksheet, and/or in the teacher notes. Your colleagues will appreciate your recognition.
How to Cite:
In-text citations with and without author – Purdue OWL APA
Reference list citations – Purdue OWL APA Rules