Below are several short videos that can help you refresh your knowledge of some of the main topics under the Nature of Science Topic. This is not meant to be a complete list, but rather a summary list of some of the most important concepts that might appear on your Science PSSA test. If you have any questions about the videos, please see your science teacher and they will help you refresh your memory.  You can click on the any of the videos in the list below to go directly to its location on this page or simply scroll down to the video. As you watch the video, try to not only to pay attention but also try to recall when and where you learned that information at school.