Remember to first describe what you actually see, then interpret or give it meaning based on what you ve learned. Students need to be able to use the terms pH, acid, base, and alkaline appropriately and be able to describe cause-effect relationships with some justification, using data and prior knowledge. Students describe, predict, investigate, analyze, and explain phenomena. Students look for evidence that explains why things happen, and modify explanations when new observations and data are obtained. Students use computers to organize, analyze, and interpret data.
Resource demands can limit the growth of populations in specific ecosystems.
I prepared a station with eight or nine beakers of pond water for every five or six students. I labeled the beakers with dates from about 1965 through 1996 - so as to mimic samples being taken every four years or so. This student was able to collect appropriate data, but was unable to proceed further. The trend the student identified simply states that the pH values went down, not that they also fluctuated from 1982 - 1995. The student suggests treatments, but does not explain how or why these treatments might be used to increase the pH levels.