Grade level
Developing and using models
Constructing explanations (for science) and designing solutions (for engineering)
Patterns
Cause and Effect
Energy and Matter
PS4.A: Wave Properties
PS4.C: Information Technologies and Instrumentation
As the culminating task of the storyline, students drew models to show how information can be transferred in (a) a whisper and (b) a scream. Immediately before, students engaged in a group discussion to develop a “Gotta Have” checklist, identifying the key components to be included in students’ models and/or explanations.
Artifacts A, B, and C each forefront how a whisper and a scream are distinguished by the amplitude of the sound wave that is produced, but represent this in three different ways. Artifact A shows a directional crescent-shaped sound wave, smaller and closer together for a whisper in contrast to the scream. In addition, notice what might be an overlaid graphical representation of the sound wave, identified with the terminology of ‘amplitude.’ Artifact B, likewise, shows a graphical representation; however, it is worth noting that without the use of axes for the graphical representation, it is possible that the student is instead depicting sound as a transverse wave. Artifact C depicts the amplitude using a “sound radar,” which is a bar graph representation of the sound wave’s amplitude. In all three cases, there is limited evidence of the mechanism by which sound is produced or how the sound wave travels from one place to another.
Artifacts D, E, and F each establish part of the causal story for how sound transfers information. Artifact D attends to the vibration of the neck (or, voice box) in the making of the sound wave, in addition to the graphical representation of the sound’s amplitude (note, too, the drawn horizontal axis). Artifacts E and F both show how air molecules interact as a sound wave passes through the medium of air, with Artifact E showing how sound travels through “vibrations in air” and Artifact F most clearly visualizing the invisible vibrations of air particles as compression waves caused by different types of sound, albeit confounding amplitude with frequency.
While Artifact G may be the most visually appealing, it shows only an emerging understanding of how sound carries information – the size and directionality of the radiating crescents offer a simplistic representation of a compression wave emanating from their sources, but with no indication that the information is coded in the wave pattern or that it must be decoded once received.
The video of Artifact H shows students explaining their model verbally, which captures a number of additional aspects of students’ understanding, including:
