In relation to Station #3, Artifacts A and B observe, at a macroscopic level, that sound can be caused by direct impact between two or more objects. Artifact C extends this concept of impact to the physical concept of “force” and relates this to the volume of the produced sound; it also explains that the vibration of a material causes sound.

In relation to Station #4, Artifact D, E, and F together observe that the amount of water in the glass is related to the pitch of the sound produced (the more water, the lower or deeper the pitch, and vice versa). In these artifacts, we have more diversity in how students conceive the causal story for the production of this sound. Artifact D suggests that vibrations in the glass cause the sound to travel through the air (in addition to identifying energy), whereas Artifact E suggests that the sound is related to an echoing phenomena – perhaps an initial description of the concept of resonance. Similar to Artifact D, Artifact F references vibration, and notes the conditions under which the glass material remains vibrating. Artifact G shows students experimenting with making these sounds; note, in particular, how one student feels the vibration of her finger along the glass edge, while another sees a consequent motion of the water, also described as a form of vibration. 

The video in Artifact H serves as a suitable summary of these artifacts. While the student explains that vibration can cause sound, she also indicates that an impact can also cause noise. Across the artifacts, there is limited evidence for a mechanical understanding for how sound travels from place to place as a pressure wave.