DQC WorkshopDetroit Airport Westin - November 20, 2010

Wright Room, Westin Hotel

• Diagnose how students use or don’t use key principles (tracing matter and energy) to reason about biological phenomena .

• Explore how teaching strategies may improve principle-based reasoning by college-biology students.

Overall Goals of the DQC Project

• MSU researchers formed a group to look at college-student (MSU) understanding of key principles related to matter, energy, and information.

• CCLI Phase 1 grant (years?)– faculty development combined with science education research, three years worth of annual workshops at Ecological Society of America annual meeting, data collected from students at 15 institutions, BioScience paper from the large data-set, lots of more specific posters based on parts of the data-set and several papers in preparation by faculty participants

• CCLI Phase I grant (years?) - faculty development combined with science education research, two annual meetings, most faculty involved teach Introducory Biology, DQCs expanded and repackaged to target cellular/molecular through ecosystem level.

History of the DQC Collaborations

• List as many student alternate or misconceptions about carbon transforming processes (e.g. Ps, Rsp) as you can in 3 minutes.

• Group those conceptions depending on whether they are related to tracing matter, tracing energy, or choosing appropriate scales at which to reason.

Conceptions about carbon transforming processes

Research Goal: Connect conceptions to principle-based reasoning

We investigated college students’ ability to apply the principles of conservation of matter and energy across scales when reasoning about biological processes that generate, transform, and oxidize organic carbon molecules.

Summary of 08-09 Findings

Methods• Pre- and post-DQCs to 495 students at 12 institutions

• In between the pre and post-tests, faculty used active teaching strategies that targeted principled reasoning about matter and energy

• Faculty coded their own students’ responses. We regrouped responses. Codes were “scientific”, “mixed”, “informal”, or “no data”

• Looked for quantitative trends (pre-post gains, differences in difficulty among processes, principles, and scales)

• Looked for qualitative trends

Key Findings

• Some students applied principle-based reasoning (9% in pre-tests and 24% in post-tests).

• Some applied informal reasoning (20% in pre-tests and 15% in post-tests).

• Most (62% in pre-tests and 55% in post-tests) applied mixed reasoning.

Characteristics of answers in each group

• Principle-based reasoning – Able to trace matter and energy across scales

– Don’t confound matter and energy or think either than disappear

– Can account for individual atoms and molecules as they are rearranged

• Mixed reasoning– Awareness of “invisible” processes, but insufficient knowledge to describe them

– Confound matter and energy

– Oversimplify laws of conservation

– Use informal language in part, but not all of answer

– Prolific use of school science terminology

• Informal reasoning– Make no attempt to trace matter or energy

– Rely heavily on informal language or inappropriate analogies

Key Qualitative Findings

1. Students confound energy and matter and use of energy as a “fudge factor”

2. Reasoning across scales is hampered by a lack of understanding of atoms and molecules

Use of Energy as a “Fudge Factor”

• Students often chose distracters that indicated that they thought energy could become matter and matter could become energy.

• Students often chose distracters that included energy disappearing, being “used up” or being “burned up”.

– Indicates that they are drawn to words used in informal discourse

– Indicates that they are drawing inappropriately narrow boundaries around systems which is a problem related to scale. Once energy leaves the boundaries, students no longer feel the need to account for it.

• Use of energy as a “fudge factor” was more common when students were asked to reason at the atomic-molecular level

Findings: Energy as a “Fudge Factor”

A potato is left outside and gradually decays. One of the main substances in the potato is the starch amylose ((C6H10O5)n). What happens to the atoms in amylose molecules as the potato decays? Choose True (T) or False (F) for each option.T F Some of the atoms are converted into nitrogen and phosphorous: soil nutrients. T F Some of the atoms are consumed and used up by decomposers. 88%T F Some of the atoms are incorporated into carbon dioxide. T F Some of the atoms are converted into energy by decomposers. 85%

A loaf of bread was left uncovered for two weeks. Three different kinds of mold grew on it. Assuming that the bread did not dry out, which of the following is a reasonable prediction of the weight of the bread and mold together?A) The mass has increased, because the mold has grown. B) The mass remains the same as the mold converts bread into biomass. C) The mass decreases as the growing mold converts bread into energy. 11%D) The mass decreases as the mold converts bread into biomass and gases.

Findings: Energy as a Fudge Factor

• For questions that explored matter-energy conversions– 21% of students chose the distracter in a

multiple-choice question– 56% of students chose the distracter in a

multiple T/F questions

Findings: Energy as a Fudge Factor

• Students commonly ignore the energetic costs of transformation of matter and energy in trophic web.

• When asked “Of the energy gained by a plant (i.e. producer), what percentage is typically transferred to a rabbit that eats the plant?”, 65% of students thought more than 20% of the energy gained by a plant would be transferred to the herbivore that consumes it.

• When asked about energy transfer through a food web, only 47% of students thought the top of a food web would have “less available energy than the trophic levels below it”.

• When asked about decomposition, 28% of students thought the mass of mold and the bread upon which it is growing would stay the same as the mold grows.

Key Qualitative Findings

1. Students confound energy and matter and use of energy as a “fudge factor”

2. Reasoning across scales is hampered by a lack of understanding of atoms and molecules

Students lack an understanding of atoms and molecules

• Without an understanding of the particulate nature of matter, students cannot trace matter and energy across scales. They are limited to reasoning only at the macroscopic level.

• Students think molecules are equivalent in terms of the energy they contain.

• Students think atoms can be converted to other atoms or they don’t use this as a constraining idea.

• Students see overly simplified gas-gas and solid-solid cycles as a result of being uncomfortable with atoms and molecules.

Students lack an understanding of atoms and molecules

A potato is left outside and gradually decays. One of the main substances in the potato is the starch amylose ((C6H10O5)n). What happens to the atoms in amylose molecules as the potato decays? Choose True (T) or False (F) for each option.

T F Some of the atoms are converted into nitrogen and phosphorous: soil nutrients.

T F Some of the atoms are consumed and used up by decomposers.

T F Some of the atoms are incorporated into carbon dioxide.

T F Some of the atoms are converted into energy by decomposers.

T F Some of the atoms are incorporated into water.

277T, 165F

274T, 167F

315T, 122F

154T, 287F

228T, 212F

Discussion

• We saw some learning gains, but the majority of students were still using “mixed” reasoning even after instruction.

• Why do you think this is?• What do you think we can do about it?

Conclusions

• Principled reasoning is difficult for students most likely because– They lack the necessary understanding of atoms and molecules.

– They reason about mega or micro-scale phenomena by inappopriately applying cultural models or their own embodied experiences, both of which are situated in the macroscopic world.

• Theories about language and informal reasoning may be useful in interpreting why students have difficulty moving from informal to scientific discourse. Students look for “actors” that drive processes. They have trouble thinking of atoms, molecules, and cells as actors. When they think about organisms as actors, they are precluded from thinking about the components/cells within the actors, making it hard to move across scales.

Conclusions

• Science instructors at multiple levels and in multiple domains need to help students see the necessity of principled reasoning and how their cultural models interfere with principled reasoning and to alter their course-taking practices.

• This doesn’t mean that we can forgo the details. Instructors need to give students to tools that enable them to connect the details of course content and student responses to the principles behind them.

Summary of 09-10 Data Generated

Data Generated by Your Students

DQC # Pre (# classes) # Post (# classes)

Photosynthesis A 49 (2) 45 (1)

Photosynthesis B 33 (1) 47 (2)

Respiration A 403 (3) 221 (4)

Respiration B 117 (2) 439 (4)

Biosynthesis A & B None None

Energy Pyramid 49 (1) None

Rainforest 132 (1) 182 (2)

Biofuels 40 (1) 38 (1)

Grandma Johnson 161 (2) 163 (2)

Keeling Curve 59 (2) 52 (2)

Preliminary Findings From the 2009-2010 Data

• Not sure what to put here

Where we go from here

Next Steps

• A “methods” paper is in progress.• Work toward further validation of the items (IRT analysis,

interviewing students)• Tie college-level data to K-12 data on learning

progressions.• Continue to support “spin-off” and “follow-up” research

conducted by faculty participants.• Continue to explore efficacy of teaching strategies• Development of DQCs for evolution and biodiversity.