A comparison study on American and Chinese secondary students’ learning progression for carbon cycling in socio-ecological systems

Jing Chen Charles W. Anderson

Michigan State University

Xinghua JinShanghai College of Business

2009 AERA Annual Meeting, San Diego

Apr. 16th, 2009

Environmental and social background

• The topic of carbon cycling has its unique scientific and practical importance. The imbalance of carbon transforming processes is the primary cause of global climate change.– US and China are two countries with top carbon emission rates.

• American and Chinese citizens are by and large uninformed or misinformed about environmental science. (KACEE News, 2005; NEETF & Roper, 2001, Chen, 2006, CEAP, 2008).

The investigation of American and Chinese students’ understanding of carbon cycle and how their understanding progresses over time is a necessary first step to find out ways to improve science education.

Theoretical framework

• Carbon transforming processes• Learning progression levels • Fundamental scientific principles

Photosyn-

thesis

Digestion/

Growth

Cellular respiration

Combustion Cross processes

Large-scale

Level 4: Qualitative Model-Based Accounts of Processes in Systems

(Carbon-transforming processes)

Level 3: “School Science”Narratives about Processes

Level 2: Causal Sequences of Events with Hidden Mechanisms

Level 1: Separate Macroscopic Narratives

Upper Anchor

LowerAnchor

Tracing matter: matter conservation principle

&

Tracing energy: energy conservation and energy degradation principles

(Fundamental scientific principles)

Research questions:

• How do American and Chinese students compare in terms of the accounts they give for carbon transforming processes and for fundamental matter/energy principles?

• How do general achievement levels compare for American students and Chinese students?

• What are the implications for the validity of learning progression levels for these two groups? How do item difficulties compare for American and Chinese students?

Research Methods

• Participants: 600 American and Chinese student in total

– 150 at middle school level and 150 at high school level for each country

– Michigan rural/suburban public schools (2 middle and 3 high schools); Shanghai (urban) public schools (2 middle and 2 high non-key schools)

– Samples are representative for average students in Michigan and average students in Shanghai

• Assessment items: 31 items

– Developed in English, translated into Chinese

– Tried out first

– 3 test forms, even distribution

– Middle and high school items overlap

– 100~200 responses for each item from each group

• Data analysis– Same scoring rubric– IRT analysis (Partial credit model)

Matter Energy Total

Photosynthesis 2 3 5

Transformation 2 2 4

Cellular respiration

5 4 9

Combustion 3 2 5

Large-scale 4 4 8

Total 16 15 31

Result 1: American and Chinese Students’ accounts for tracing matter and tracing energy in different processes

Levels Characteristics Cellular respirationWhen a person loses weight, where does the matter of the person’s fat go?

4: Model-based accounts

--Understand atomic-molecular scale--Distinguish matter from energy--Identify and conserve key organic and inorganic materials-Accounts connect atomic-molecular and macroscopic and/or large scales

CH: Fat provides the energy that body needs. Under the catalyses of enzyme, fat gradually hydrolyze into glycerin and fatty acid. Then it oxidizes and produces CO2, H2O and energy. AM: His fat was lost when the bonds of the glucose were broken down into H2O, CO2 by cellular respiration.

3: “School Science” Narratives

--Extend understanding to cellular or atomic-molecular scale.--Recognize chemical identities of some materials --Insufficient knowledge at atomic-molecular scale.

CH: Fat is a good energy store substance. When people lose weight, the ATP in fat will break down to provide the energy that people need. The chemical bonds of ATP will break up and form water.AM: When you are exercising you are burning fat away. But instead of getting energy you lose energy. When it's going away it just comes out of your body as water and gas.

2: Causal Sequences of Events with Hidden Mechanisms

--Do not trace matter and energy separately -Recognize hidden structures and mechanisms (e.g. organs, decomposers, gases)

CH: Fat is burned into energy. When there is extra energy in human’s body, energy is saved as fat. When fat burns, it provides energy for human to use. AM: Because the fat has to go somewhere so it probably burns up into energy like a fire.

1: Separate Macroscopic Narratives

--Confined at macroscopic scale--View macroscopic events as results of different “natural tendencies.”

CH: People will sweat when they are doing exercise. Fat disappears with sweating. AM: I think when you exercise the fat disappears.

Result 1: American and Chinese Students’ accounts for tracing matter and tracing energy in different processes

• Chinese and American students gave responses in the same broad range that could be classified using our 4 achievement levels.

• Broad similarities between the types of responses that American and Chinese students gave for each carbon transforming process at each level.

• Similar misconceptions– confuse matter with energy; unable to trace matter and energy separately– confuse global warming with ozone depletion– energy is released when chemical bonds are broken

• Differences: – tracing matter: Chinese students included chemical equations; used the

term “organic”, “inorganic” more often than American students– tracing energy: Chinese students included names of energy forms and

mentioned energy conservation principle commonly; but they generally did not successfully use the principle as a tool to reason about carbon transforming processes, especially in carbon generation and transformation.

Result 2: Distribution of American and Chinese students’ responses among levels

• American and Chinese students’ responses are distributed similarly across levels

• Only a small proportion of students’ responses reach level 4.

• Both American and Chinese students shift toward higher levels from middle school to high school.

• More Chinese high school students gave level 3, level 4 responses. More American middle school students gave level 3 responses.

21

54

60.6

25

52

12

0.20

10

20

30

40

50

60

N=150 American middle and 150 Chinese middle school students

Chinesemiddle

Americanmiddle

Chinese middle 21 54 6 0.6

Americanmiddle

25 52 12 0.2

level 1(%) level 2(%) level 3(%) level 4(%)

The percentages of American and Chinese middle school students' responses at different levels

The percentages of American and Chinese high school students' responses at different levels

4

55

25

8

18

53

19

40

10

20

30

40

50

60

N= 150 American high and 150 Chinese high school students

Chinesehigh

Americanhigh

Chinese high 4 55 25 8

American high 18 53 19 4

level 1(%) level 2(%) level 3(%) level 4(%)

The percentages of middle school students’ responses at each level

The percentages of high school students’ responses at each level

Result 3: Empirical Validation of levels for American and Chinese groups (a)

• The thresholds of the same levels are more clustered in the American Wright map than in the Chinese Wright map.

• Chinese students gave responses at inconsistent levels across items; suggesting that our achievement levels may not have good predictive power for Chinese students.

• Some items are easier for Chinese students to reach a certain level, while others are harder for them to reach a certain

level than for American students. Wright map for Chinese students Wright map for American students

Level 4Level 3Level 2Level 1

The step difficulties from level 3 to level 4 are lower for Chinese students.

Step difficulties from level 1 to 2 are lower for Chinese students.

Result 3: Empirical Validation of levels for American and Chinese groups (b)

Result 3: Empirical Validation of levels for American and Chinese groups (b)

• Item difficulty analysis indicate that in general, American students perform better for photosynthesis, digestion & biosynthesis, and large-scale items; Chinese students perform better for cellular respiration and combustion items.

– The item overall difficulties for photosynthesis, digestion & biosynthesis, and large-scale items are higher for Chinese students.

– The item overall difficulties for cellular respiration and combustion items are lower for Chinese students.

Discussion & Limitations

• The differences in these two groups of learners’ performances may result from factors such as curriculum, standards or teaching focus– In Chinese science education, teachers usually focus their

teaching on chemical identities, equations and scientific principles

– Science subjects such as physics, chemistry, biology, and earth science are less integrated in Chinese science education, students may have difficulty connecting knowledge from different disciplinary areas to reason about carbon transforming

processes or large-scale events. Limitations• The sample in our study is not representative for students in both

countries. • the translated test may not be considered as an equivalent test for

Chinese students

Conclusion

• Share similar general trends of learning progression from force-dynamic to scientific model-based reasoning; perform differently for tracing matter and tracing energy principles.

• Similar general distribution of responses at each level for both groups; only small percentages of responses reached level 4 --principled, model-based reasoning in both groups.

• Chinese students may follow the learning progression differently compare to American students (Levels of Achievement is less empirically valid for Chinese data than it is for American data) --For some items, the step difficulties and overall item difficulty of

the same item are different for these two groups.

Implication

• It is urgent to improve science education in both nations to help more students shift to high-level understanding.

• American science education could pay more attention to developing students’ chemical understanding and mastery of fundamental principles.

• Chinese science education could place more emphasis on developing real understanding besides knowledge memorizing.

• Chinese science education could develop students’ science interdisciplinary knowledge to help them connect multiple carbon transforming processes though multiple scales.

For more information..

•Visit Environmental Literacy website at:

http://edr1.educ.msu.edu/EnvironmentalLit/index.htm

Thank you!