Outcome:Participants will critically analyze a scientific claim and learn how to present scientific information. / Time Required:
Homework: 25 minutes
Review: 15 minutes
Ohio Standard(s)and Benchmark(s):
Science Practices: Expressing scientific information & Probability and statistics
Science Content: Interaction between Earth’s systems and living things
Session Description / Delivery Format
Handout with a brief scenario of a scientific experiment that participants will evaluate on the basis of accepted scientific practices and mean tendencies mathematics / Face-to-face conference / Facilitated online
Face-to-face structured session / Self-directed online
Other / Blended
Data Sources/Analysis Findings:
Participant Prior Knowledge:Critical thinking skills, scientific experimental design and expressing scientific information, and basic mathematical skills
Materials (including pre- and post-work):Handout
Instructional Activities
Topic / Strategy / Notes
Report of experiment findings / Participants will evaluate the reported results of an experiment to test a soil mixture on bean plant growth.
Assessment/Evidence:Assessment will be based on participant interaction and responses on homework sheet.
Technology Integration:
Ideas for Lesson Extension:Research and evaluate other scientific results or claims.
Attach handouts, storyboards, supporting resources, etc.The Green Bean Caper- Analyzing Scientific Claims (3 pages)
The Green Bean Caper - Analyzing Scientific Claims
The gardening section of the Sunday newspaper reports the results of an experiment that tested the effects of adding two different minerals into the soil. These minerals, which are not normally found in soil, were added to a generic soil mixture. The study involved a total of 20 six-inch tall bean plants from two different greenhouses. One half of the plants was transferred to a pot with the soil mixture that contained the two minerals. The other half was transferred to a pot with the generic soil mixture. The investigation determined that the bean plants from the group with the added minerals grew larger when compared to the bean plants from the other group planted in the generic soil. The researchers now want to market their minerals-soil combination.
Critically evaluate this experiment and its results.
- What do you think is wrong with the experiment?
- What do you think the researchers did right?
- What questions would you like to have the researchers answer about their experiment?
- Given the reported information, is the conclusion valid? Why or why not?
Measure the central tendency (mean, median, mode).
Table 1 provides the results of the bean plant experiment. It gives the final height of each plant in inches.
Table 1. Bean Experiment ResultsPlants with Minerals / Ending Height / Plants without Minerals / Ending Height
Plant 1 / 19” / Plant 1 / 17”
Plant 2 / 15” / Plant 2 / 14”
Plant 3 / 17” / Plant 3 / 16”
Plant 4 / 17” / Plant 4 / 13.5”
Plant 5 / 23” / Plant 5 / 22”
Plant 6 / 15.5” / Plant 6 / 15.5”
Plant 7 / 16” / Plant 7 / 15”
Plant 8 / 26” / Plant 8 / 14”
Plant 9 / 20.5” / Plant 9 / 17”
Plant 10 / 24” / Plant 10 / 18”
Calculate the mean, median, and mode of ending plant height for each test group. Place your calculations in Table 2.
Table 2. Statistical AnalysisPlants with Minerals / Plants without Minerals
Mean
Median
Mode
Evaluate the statistical data.
- What do you think the hypothesis for the experiment was? (Write the hypothesis as an “If …, then ….” statement.)
- Assuming the researchers did not falsify the results or make a measuring mistake, does the data support their claim? Why or why not?
- What might have been other ways for the researchers to have analyzed and presented
their results?
- Suppose the researchers reported the measured growth since the bean plants were transplanted (Ending Height – 6 inches = Growth). How would this change the mean, median, and mode? Would this alter the experiment’s conclusion?
- How would multiplying each plant’s height by 2 affect the results?
- List the flaws with the design of the experiment and the presentation of data.
Ohio Professional Development Network ̶ Fall 2013 Teacher AcademyPage 1 of 4