This unit has five components linked sequentially: 1. Students should research the human generated sources that have contributed to the increase in the acidity of rain. At the conclusion of their research, students should understand the scope of the problem and be able to list and explain at least three areas where rain with low pH impacts humans and the natural world. In classroom discussion, students should be able to articulate their findings and discuss the validity of sources located as well as future implications if the problem remains unresolved. 2. In the second lesson, students should be able to work in a group to determine the portion of the phenomena (effects on aquatic systems, manmade structures, plants, etc.…) they would like to study and develop a plan to test their hypothesis with the appropriate controls. The plan should be presented to the class for critique prior to implementation. If the class is unable to locate areas of weakness, the instructor should ask questions intended to guide the class in the correct direction to produce relatively valid results. However, the students are responsible for their experimental design so they should be allowed to implement the experiment even if they are unable to correct problems perceived by the instructor - the students, as a group, should take ownership. During the course of study, students may be able to correct problems as they begin to run their experiment. If the problem cannot be corrected, the students should repeat the experiment or report the problem and how a researcher in the future might correct the problem to obtain more accurate results. 3. Lesson 3 requires that students implement their plan using available materials and following all laboratory safety procedures. 4. At the conclusion of their experiment, students will produce a formal lab write up using the word processing program of their choice. Student groups should divide the workload (the sections of the report) so that everyone contributes. One chart and one graph is required and must be produced on the computer as well. The instructor may want to require a rough draft to check student understanding of the process depending on the experience level of the class in producing the formal report. 5. After rough drafts are complete, students should share their results with the class. A discussion of results should be facilitated by the instructor. Students should help each other determine areas for further research.

ABILITIES NECESSARY TO DO SCIENTIFIC INQUIRY Identify questions and concepts that guide scientific investigations. Design and conduct scientific investigations. Use technology and mathematics to improve investigations and communications. Formulate and revise scientific explanations and models using logic and evidence. UNDERSTANDINGS ABOUT SCIENTIFIC INQUIRY Scientists usually inquire about how physical, living, or designed systems function. Conceptual principles and knowledge guide scientific inquiries. Historical and current scientific knowledge influence the design and interpretation of investigations and the evaluation of proposed explanations made by other scientists. Scientists conduct investigations for a wide variety of reasons. For example, they may wish to discover new aspects of the natural world, explain recently observed phenomena, or test the conclusions of prior investigations or the predictions of current theories. Scientists rely on technology to enhance the gathering and manipulation of data. New techniques and tools provide new evidence to guide inquiry and new methods to gather data, thereby contributing to the advance of science. The accuracy and precision of the data, and therefore the quality of the exploration, depends on the technology used. Mathematics is essential in scientific inquiry. Mathematical tools and models guide and improve the posing of questions, gathering data, constructing explanations and communicating results. Scientific explanations must adhere to criteria such as: a proposed explanation must be logically consistent; it must abide by the rules of evidence; it must be open to questions and possible modification; and it must be based on historical and current scientific knowledge. Results of scientific inquiry--new knowledge and methods--emerge from different types of investigations and public communication among scientists. In communicating and defending the results of scientific inquiry, arguments must be logical and demonstrate connections between natural phenomena, investigations, and the historical body of scientific knowledge. In addition, the methods and procedures that scientists used to obtain evidence must be clearly reported to enhance opportunities for further investigation.

Students should understand the components of the scientific process. Students should be able to define and apply associated terms such as observation, hypothesis, variable and control.

If the class is unable or unwilling to begin suggesting an experimental design during lesson 1, the instructor should not provide answers but should prepare an experiment that is completely incorrect and allow students to identify the problems - engaging students in a critique of unexpected teacher generated, experimental design errors. Instructor should pretend to be completely serious, pretend this is a legitimate experiment that you are very proud to share - no smiles. Use four dishes, all of different sizes and composition. Inside separate dishes place construction paper scrapes, newspaper nibbling and paper towel tidbits. On top of the paper fragments, place several different seeds with contrasting colors: grass, thistle, corn and weed seeds. In each dish, place different amounts of water; drowning some seeds while only slightly moistening others. To the water in the dishes, add four different test substances: salt, sugar, cola and vinegar. To make the lab cost effective, I included dishes previously utilized for artistic endeavors; several dried paint drippings remained on the side. A fortuitous event had taken place in the two dishes in which I had used construction paper; the color had leached into the water combining with the paint to produce the most aesthetically appealing lab set up ever created. Ask the students if this is a valid test if the hypothesis is, "Lowing the pH of the growth medium will prevent seeds from germinating." Several incorrect hypotheses should be suggested to test student understanding of that important concept (Example: Do seeds grow when something is added? What does acid do to living things?). Students should be allowed to critique the experimental design and should eventually be able to determine that if the experiment were valid, the dishes should be sterilized and all the same size, the seeds should be the same age and kind, the water should be added in the same amount at the same time and so forth. Eventually students should also notice that this experimental design has no control. How can we determine the impact of acid on seed germination if we do not know when the seeds are suppose to germinate? Students should then be divided into multicultural, nonsexist groups by interest and asked to design an experiment that will test the phenomena that most interested them. For students to retain ownership, the instructor must allow students to create their own lab design. Anything goes as long as students are testing the impact of acid rain on living things and manmade structures and as the students have a control and experimental group, they have controlled all variables and know which is their independent and how their dependent will respond and, how they intend to collect data (everyone should have a data table that will later become a computer generated graph.) On the following day, students should present their plan to the class for a critique. Teacher will need to approve and purchase the supplies required by each group.

Assessment of the discussion is informal. From the amount of time it takes students to locate the errors in the teacher created lab, the instructor can determine the depth of student understanding. The teacher can ask, "If this is my hypothesis, how can I set the lab up to get valid, scientific results." Other examples may need to be presented of both good and bad lab designs. After students have constructed their experimental design, the instructor should collect the materials to determine the following: hypothesis stated correctly feasibility of experimental design data collection technique control variables identified materials listed Again, the instructor should only identify potential problems and attempt to guide students but should not provide solutions. If the students do not correct problems in experimental design in advance, they should be allowed to attempt the experiment and discover the problems as they progress.

Students should be able to identify flaws in an experiment that was set up incorrectly and recommend the method necessary to test the phenomena that would produce valid results; student recommendations for correcting lab design can serve as an informal assessment. Students should then be able to plan an experiment that will test their understanding of the process of science. Student plan should include the following: hypothesis: materials required: control: variables (identify the independent variable): data collection technique: