Modeling the scientific method with an Unknown Object (Jared penland)

Title: Modeling the Scientific Method with an Unknown Object

Principle(s) Investigated: Scientific Method, Inquiry, testing an hypothesis.

Standards : Investigation and Experimentation 1c, d, f, k, and j.

Materials:

Oak gall - advanced development

Oak gall attached to branch

Developing oak gall within a branch (same color as the bark)

Oak branch with acorn and leaves to identify the type of plant the gall came from

Research paper: One sheet from on online deictionary about oak trees that mentions gall wasps

Picture of an oak tree and oaks galls on the tree

*Oak galls can be obtained from most native oak trees

Procedure:

1. Each student is given an oak gall. Do not tell them what it is! Ask the students to refrain from guessing what it is or telling anyone if they know what it is. (The galls are created when wasps lay their eggs in the cambrian layer of the tree.) The teacher then asks the rhetorical question, "What is this?" An anticipatory set may be used by beginning: "As you walk through a forest you noticed this strange object on the ground."

2. Write on the board "Observations"

Have the students oberve their oak gall. List their observations on the board.

Some observations may be: brown, round, light density, pin holes, irregular attachment sites etc...

Write on the board "Guesses."

Ask the students to now guess what the object may be, list their guesses on the board.

Some guesses may be: mushroom, infection, tumor, insect nest, feces, fruit or nut etc...

3. Handout the second evidence: oak gall attached to a branch. Now the object is directly observed as being of plant origin. Add new observations and guesses, remove guess that are now contradicted by the new evidence; such as feces.

4. Handout the third evidence: oak gall within a branch. This will cause the guesses to be forced to involve processes within the branch; such as: bruises, fruits, buds, infections etc... Add new observations and guesses, remove guess that are now contradicted by the new evidence.

5. Lastly, handout the forth evidence, the branch with the acorn and leaves. At this point, guesses like fruit or nut are contradicted because the reproductive structure of the oak is the acorn. Remaining guesses may be: infection, or other internal swelling.

6. Ask the question, "we know that this acorn is associated with oak trees -- genus Quercus -- what can we do now? The students should respond with "look up oak trees in some reference source." Now pull up the oak tree handout. here is their reference -- they do not have to look it up themselves.

7. Have the students read the handout and identify the relevant information in the first paragraph, line 16 "...oaks galls, which are pea to egg sized growths." In line 17 this is followed by "...formed by oaks around the developing gall wasp larva."

8. We now have a hypothesis in which to test. Ask the question: "We now believe from our research and observations that as small wasp is responsible for infecting an oak tree--the holes are the results of burrowing wasp larva through the branch tissues. How can we isolate the wasp as the cause of the gall (effect)?" This could be a homework assignment, or a journal entry. One way you oculd test this would be to have two oak trees sealed off from each other. With one tree place the wasps and the other tree have no wasps.

9. Since you have a control group of oak trees with not gall wasps and an experimental group with wasps you can make tables and graphs through a though experiment. "What would you expect to happen with the trees with no wasps?" and "what do you think would happen with wasps?" On the board show what the table and graph should look like. Emphasize cause and effect in the data presentation. At this point an explanation of of dependent and independent variables could be introduced.

Student prior knowledge: This lesson comes at the begginning of the year and reintroduces them to the scientific method from 7th grade. Basic questioning and observation skills are needed.

Explanation: The objective of this lesson is to introduce students to the process of observation, hypothesizing and formation of a controlled experiment using an object commonly found in california oak forests. the emphasis is placed on asking questions from a series of observations provided by the evidence presented by the teacher and arriving at a testable hypothesis. The teacher needs to be flexible with following the responses from the class. Each class will vary in how they answer the questions.

Questions & Answers:

1.What are the steps of the scientific method?

Answer:

1. Ask and define the question.
2. Gather information and resources through observation.
3. Form a hypothesis.
4. Perform one or more experiments and collect and sort data.
5. Analyze the data.
6. Interpret the data and make conclusions that point to a hypothesis.
7. Formulate a "final" or "finished" hypothesis.

2. Why is the control group so important in making an experiment to find the cause of something?

Answer: The control group is important in making an experiment and finding the cause because without the control group then the effect could have been caused by anything and you have no baseline in which to compare your experimental group and the variable in which you changed.

3. Why is research so importnant when seeking to solve a problem or forming a hypothesis?

Answer: Research is important because it helps guide and inform the way you test your hypothesis. it may be that you experiment had already been done or it may inform you of additional variables effecting your outcome that you had not previously considered.

Applications to Everyday Life: The skill of observing and asking questions is an important skill to possess in order to be successful. For instance, if your vacuum cleaner breaks and don't have the money to have someone fix it, you can observe what is happening, and isolate specific variables in conclude what is causing the vacuum to not work properly.

Another example would be if you were a gardner and your plants began to die. By isolating various variables such as shade, soil alkilinity, water usage, you can through the process of elimination, observation and testing conclude why your plants are not thriving.

And last, an example of where students can use the skill of observation and hypothesis is in everyday life. Often times we are confronted with a problem and need to solve it, such as why our light doesn't come on when we flip the switch or why our speakers have stopped working on our computer. By observing, creating a hypothesis and then testing the hypothesis you can learn to solve most problems for yourself and save a lot of money by not having to hire a professional to help you.

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