10/16/03Bohanan/Niemi/Wachtel1 Experimental Design & Motivating Student Questions Robert Bohanan,...

10/16/03 Bohanan/Niemi/Wachtel 1

Experimental Design &Motivating Student Questions

Robert Bohanan, Center for Biology EducationWEEB II


Opportunities for Investigation at Different Scales

• Individual organism• Population(s) of a particular

species• Interactions between and among

species - communities• Movement of matter and energy -

ecosystems


Group Assignment

• In groups of 2-3 think of 5-10 Questions that you have about garlic mustard at the school forest


Research Projects Initiated By Schools As Part of SchoolYard

Science (SYS)• Life history and natural history of native and

non-native organisms• Succession and the impact of invasive

organisms in schoolyard habitats• Biological diversity of restored wetland

habitats• Development of a woodland management

plan for school forest habitat• Seasonal comparison of aquatic

invertebrates in a small river• Phenology of a vernal pond• Comparison of 2 urban sediment detention

ponds*• Modeling nutrient dynamics in aquatic

microcosms*

• *Specific classroom study on student learning (Science Scope In Press Fall 2005)

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Motivating Students to Ask Questions and to Guide Their Investigations:An Active Learning Exercise

• What is an Invasive Organism?

• How are Invasive Organisms different from Native/Natural Organisms?

• Why do you think that people are interested in invasive organisms?

• In your group identify and list 5-10 characteristics or traits of an invasive organism.

• How are these traits similar and different to native or natural organisms?


Some Previous Work

• Life History and Natural History of Invasive Organisms– Characteristics of invasive plants– Comparison of native and non-native

plants in SYS habitats– Developing an invasive plant

management plan for SYS habitats


Ways of Thinking About Data

• Databases that provide background on plants and animals

• Databases that provide additional resources

• Databases that may be queried

• Real-time remote sensing data


Motivating Student Questions:A 6th Grade Classroom Study

• Questions initially grounded in observations

• Productive questions lead to scientific inquiry

• Classroom discussion makes explicit links between questions and evidence

• Collaborative research project on model-based reasoning with Lucas, Broderick, Lehrer, and Schauble


Initial Questions From Students After Observations At Ponds

• How much blood can a leech suck in an hour?

• Are there more fish in our pond?

• Where does the water come from?

• What happens to the animals in the winter?

• How does the water in the pond get polluted?

• Is the animal life in pond 2 more diverse than pond 1?


‘What Makes A Good Question?’ Initial Criteria Developed By Students

• Easy to answer

• Meaningful / valuable

• Genuine

• Researchable

• Can not be answered yes or no


‘Connecting Questions-Evidence-Arguments’ Revised Criteria Developed By Students

• Simple and understandable• Investigator has an expected

outcome• Methods are clear from the

wording• Connected to other questions• Revision of initial question• Genuine: don’t already know

the answer• Research is doable given tools,

knowledge, and supplies• Sensible/meaningful; adds

knowledge


Synthesis of Classroom Observations and Interviews

• Initial arguments based on personal beliefs

• Initial arguments based on single undocumented observations

• Classroom discourse and teaching shifted arguments to evidence

• Evidence includes documented observations, research of others, & empirical results

• Repeatability of results


Changing Students’ Beliefs About Evidence

Because I said soBecause someone told me soBecause an authority said soBecause I observed and documentedBecause I conducted an experimentBecause I communicated my findings clearlyBecause I created a model based on researchBecause I only included evidence specific to my model

Summaries of classroom discussion and interviews with students to reflect changes in views of evidence over the course of the school year


Conclusions From Classroom Study

• Student research questions were more sophisticated when classroom design included discourse among students and also with content experts (e.g. ecologists, botanists, etc.)

• Student research was more sophisticated and iterative when it was imbedded throughout the year rather than in isolated units of instruction

• Students developed and revised models based on their research findings and used these to create arguments


Some general background

• Select an area or habitat that has some diversity of vegetation. Ideally this habitat would have some mix of grasses, broad leaf plants, shrubs, and trees.

• What do you know about the history of your study site? Is it a remnant of a larger woodland? How has the land use changed near your site over the past 50 years?

• How is the habitat managed (e.g. evidence of mowing grass, cutting trees or shrubs, application of fertilizer, herbicides, or pesticides)? What is your evidence and source(s) of information?

• What are the annual averages of rainfall and temperature for your site? What is the annual average of snowfall for your site? What is your evidence and source(s) of information?

• Has your site experienced a major windstorm, ice storm, flood, drought, or fire in the last 50 years? In the last 10 years? What is your evidence and source of information?

• Does your site have an invasive organism? When did the invasive organism first appear? Where did the invasive organism come from? How did it get to your site?


Describing Your Site

• Draw a map of your site. This may be a sketch, a detailed map that shows dimensions and topography, or a GIS map generated from GPS recordings.

• What surrounds your site? Generally, describe the surrounding land that you can see from the middle of the site.

• How would you generally describe the most obvious vegetation in your site? Wooded? Mostly shrubs? Mostly grasses and broadleaf plants?

• How would you describe the soils in your site? Wet or Dry? Sandy? Leafy?

• If most of the plants in your site were leafed out and you were sitting in the middle of the site, would it be sunny or shady?

• Map the location of each tree and shrub on the map of your site. Include the location of patches or areas that are grasses and or broad-leaf plants.


Some Initial Research Questions

• What types or species of trees, shrubs, grasses, or broad-leaf plants are present at your site? Which of these species of trees, shrubs, grasses, or broad-leaf plants are native to this area? Which are not-native to this area?

• What are the relative abundances of the different types of trees, shrubs, grasses, or broad-leaf plants at your site? Which is the most abundant? Which is the least abundant?

• What are the relative ages of the trees at your site? Size (especially the trunk diameter at chest height) is a relative indicator of age. Are most of the trees at your site larger and older or smaller and younger? Does this depend on which species of tree that you’re looking at (e.g. Burr Oaks compared to Silver Maples)?

• Can you compare the diversity, relative abundance, and age of the trees at present with any historical information? If so, how have these aspects of the site changed from past – present?

• Based on the species present at your site and what you know about their relative abundance, their relative age, and their environmental sensitivity (e.g. can that species survive, grow, and reproduce under a wide or a narrow range of conditions) which species at your site would be more vulnerable than others to invasive organisms? How? Why? What is your evidence?


Specific Questions About Garlic Mustard

• How has the distribution of garlic mustard changed following its introduction?

• Is the density of garlic mustard increasing, decreasing, or staying about the same? Note opportunities to use management as a variable comparing managed and unmanaged areas.

• Is garlic mustard affecting the growth, density, or distribution of other vegetation? Note this could be native and / or other invasive species.

• Is garlic mustard affecting the phenology of any organisms in the habitat?

• What habitat characteristics may increase or decrease opportunities or likelihood of future establishment after introduction? Opportunity to gain predictive insight with management implications or in other words what are some of the most vulnerable (in terms of susceptibility to establishment of garlic mustard) areas of the school forest.

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