Instructions

Class Period One: Designing Labs

Note: you can prepare the lab stations yourself or assign a few students to set up and “man” each station.

1) Print out Teacher Background “Station Instructions.” Cut into sections and place each instruction at its appropriate station.

Set up six stations for students to visit in order:

• Station #1: Potting soil and 2” pots (2 per group, filled ¾ way with soil)
• Station #2: ‘A‘ali‘i seeds (5 seeds per pot)
• Station #3: Labels and indelible markers
• Station #4: ironwood needles (enough to cover pots with 1” layer), spray bottle filled with water
• Station #5: Student Page “Ecosystem Engineers”
• Station #6: Student Pages “Ecosystem Engineers Lab Report” and “Daily Data Sheets”

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2) Lead a discussion on the scientific method.

Question: What are the steps of the scientific method?
Answer: The scientific method begins when you 1) ask a general question and 2) conduct some background research. Next, you 3) develop a hypothesis and 4) test the hypothesis in a controlled experiment. 5) Collect and analyze results. 6) Determine whether your hypothesis is true or false, based on your results. 7) Report your results and conclusion. If your hypothesis is false, you can begin the process again with a different hypothesis.

Writing a hypothesis as an “if… then” statement is a prediction of the results you need to support the hypothesis. For example: If ironwood needle cover benefits seedling growth, the seedlings germinating under ironwood needles will grow 20 percent taller than the control.

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3) Break the students into groups of 2-3 and have them visit stations.

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4) Arrange pots under a window or light table. Each group will spray water their pots every day for 2-6 weeks. (Assign students to take their groups’ pots home over weekends.) They will record data for each pot (control and ironwood cover) on their Student Page “Daily Data Sheet.” After the seedlings sprout, students will record the total number of sprouted seedlings and the height of the two largest seedlings from each pot.

Class Period Two: Analyzing and Reporting on Results

1) After two weeks, collect the completed Student Page “Daily Data Sheets” from each group. Summarize the entire class’s data in charts and graphs. These charts and graphs can be drawn on graph paper or created as computer spreadsheets. Discuss why scientists calculate their results in a variety of ways, ie: using mean number and median.

For example, have students calculate the mean number of days it took seeds to germinate for both the variable and the control. Display germination time in a bar graph, with the x-axis having two categories (ironwood cover, no ironwood cover) and the y-axis being the average number of days. Do the same for seedling growth. Determine the median days to germination and display in a table. Do the same for seedling growth.

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2) Hand out the “Lab Report Guidelines” worksheet and review it with the students. Have students complete their “Ecosystem Engineers Lab Report” based on the data gathered by the entire class.

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3) The students will then make a poster out of their experiment to put on display for the class. The poster should include their hypothesis, a brief version of their procedure, and their results, including the graphs they made.

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4) Place the posters on display in the classroom. Students can do a gallery walk, providing constructive and positive comments about each poster by writing it on a sticky note and placing it on the poster.

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5) Have the students turn in their “Ecosystem Engineers Lab Report.”