Which images can I use for my classroom presentations or online courses?
Using images for educational purposes falls under the Fair Use clause of Copyright Law - for a limited basis for specific purposes without the permission of the copyright holder. This means that you are open to using any image for presentations in class lectures or inclusion in your Learning Management System. Note: It is imperative that you cite your images to avoid plagiarism.
Which images can I use for my published articles, book chapters, books, etc.?
Publishing images in a published work are more complex and you need to be thorough in ensuring that you are permitted to use the image in question. Contacting the author of the image and gaining permission in writing is essential. Two easy alternative routes are to create your own visual image or visit online resources that contain copyright-free images to circumvent asking for permission.
How do I know the origin of an image is truly copyright-free?
This is a complex issue since anyone can copy any image online, download it and claim copyright-free status. If you are unable to truly know for sure, I would advise not to use. Evaluating the source of where the image resides is one item that may help with your decision.
Should I cite images I use in my PowerPoint presentations for class?
Yes. This a good habit to adopt and use the citation style most commonly used in your discipline. At the very least, include a URL or link to the image if the author and/or title is missing. For example, “Image taken from:…[link here]” or “Image Retrieved from:…[link here] providing enough information to allow others to find your source.