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Questions we ask and Misconceptions Questions we ask and Misconceptions of Chemical Concepts in African of Chemical Concepts in African

ContextContext

Sileshi YitbarekMünster June 22, 2006

QUESTIONS WE ASK

Content(Text book…)

Evaluation(bewerten)

Goal(Zweck)

Instruction(Teaching-Learning)

Questions we ask: Traditional Versus Conceptual Questions in Chemistry

Purpose: – To compare achievement on the Traditional Vs Conceptual

questions.

Area of Study:– Stoichiometry– Gas Law

Instruments:– Two-tiered Questions

(Traditional versus Conceptual Questions)

Methodology:

Subjects: First year students of Natural Science Stream, KCTE.Addiss Ababa – Ethiopia.

Sample size: 38 out of 96 students

Sampling: Simple Random

Test:Two-tiered questionnaire

Analysis:f, %, X2

Categories of Questions:

I. Traditional: Lower-order questionsa. Recall: facts, definitions or recall explanations.

Example:1. What is the symbol for Potasium?2. Define ionization Energy.

b. Algorithimic: use information or processes in a familiar way.

Example:1. A given mass of gas occupies 5L at pressure of 0.5atm and 50 K. Calculate the

pressure of the gas if it is cooled to 10K at constant volume.2. Determine the chloride ion concentration in a saturated solution of AgCl

(Ksp = 1.8 x 10 -10)

…………………..Categories of Questions:

II. Conceptual: Higher-Order Questions

– Transfer of knowledge to a new situation– Assess underlying ideas behind chemical phonemena– Cause to visualize a system and reach a conclusion

Example:Iron combines with oxygen and water from the air to form rust. If an iron nail were allowed to rust completely, one should find that the rust weighs:

(a) less than the nail it came from.(b) the same as the nail it came from.(c) more than the nail it came from.(d) It is impossible to predict.

What is the reason for your answer?___________________

Question 1: ( Traditional)Balance the following reaction: N2 + H2 NH3

Question 2: ( Conceptual)Which of the following pictorially represent the above balanced chemical

equation? Let: =Nitrogen; and = Hydrogen

(a) + (b) + (c) + (d) + (e) +

A. Stoichiometry (Lythcott, 1990; Nurrenbern & Pickering, 1987)

N2 + 3H2 2NH3

……………Stoichiometry

Table: Frequency and Percent responses for traditional and conceptual Stoichiometry question Question 1: Traditional

(N=38) “f” and “%” of students answers to traditional question

Question 2:Conceptual (N=32)

“f” and “%” of students correctly answered conceptual question out of those who answered the traditional question

Correct Incorrect Correct Incorrect Stoichiometry c a (7) b (9) d(3) e(0) f(9) Frequency (f) 32 6 4 28 Percent (%) 84% 16% 12.5% 87.5%

• Conclusion:– Additive view rather than an Interactive one.– Lack of understanding of the purpose of Coefficients and subscripts– Students perceive the balancing of equations as a strictly algorithmic

(plug- and-chug)

B. Gas Law (Mulford, 1996)

Instruments:

Question 1: (Traditional)A given mass of gas occupies 5L at pressure of 0.5atm and 50 K. Calculate the presure of the gas if it is cooled to 10K at constant volume.

a. 2.5 atm b. 0.5 atm c.0.1 atm d. None

Questions 2:(Conceptual)

The following diagram represents a cross section area of a 5L steel tank filled with hydrogen (H2) gas at 50K and 0.5 atm pressure. ( The dots represent the distribution of H2 molecules)

If the tanker is cooled to 10 K, which of the following diagrams illustrate (show) the distribution of Hydrogen (H2) molecules, assuming there is no change in state.

………………………Gas law

Table: Frequency and percent responses for Traditional and Conceptual gas question

Conclusion:The above questions were framed to ask students to relate temperature and gas distribution in the absence of change of state and volume.

Students miss the very important concept that relates:• T = K.E= Speed• Gases occupy the entire volume of the container

Question 1: Traditional (N=38)

“f” and “%” students answers to traditional questions

Question 2: Conceptual (N=33)

“f” and “%” of students choosing particular answers to conceptual question out of those who correctly answered the traditional question

Correct Incorrect Correct Incorrect Gas Law C (a,b,d) a b (3) c (15) d(3) Frequency (f) 33 5 12 21 Percent (%) 87% 13% 36% 64%

Summary: Finding and Analysis for Conceptual and TraditionalTable: Frequency and Percent responses for traditional and conceptual questions Question 1:

Traditional (N=38) “f” and “%” students answers to traditional questions

Question 2; Conceptual (N=38) “f” and “%” students answered to conceptual questions out of those who correctly answered the traditional questions

Correct Incorrect Correct Incorrect Gas Law C (a,b,d) a b (3) c (15) d(3) Frequency (f) 33 5 12 21 Stoichiometry c a (7) b (9) d(3) e(0) f(9) Frequency (f) 32 6 4 28 Average 33 6 8 25 Percent 85% 15% 24% 76% Conclusion:• Only about one-fourth correctly conceive the concepts of Gas law and

stoichiometry• Computed (X2 = 26.57)> Critical value (x2 = 6.64) at <0.01 and df=1

Success= Traditional >Conceptual ( In Both gas Law and Stoichiometry)

Recommendation:

Teachers should include conceptual questions when they examine

Pictorial representations of the Micro-level should be included in:

Students textbooks, and Instruction

References:

Fensham, P. et al.(Ed).(1994). The Content of Science: A constructive approach to its learning and teaching. UK: The Falmer Press

Gabel,D.L, Samuel, K.V. and Hunn, D.(1987). Understanding the Particulate Nature of Matter. Journal of chemical Education.Vol.64 No8pp.695-697

Mulford, D. R. (1996). An Inventory for Measuring College Students’ Level of Misconceptions in First Semester Chemistry. A thesis submitted to Purdue University.

Nakhleh, B.Mary. March (1992). Why Some Students Don’t Learn Chemistry. Journal of Chemical Education. Vol69, No3, pp.191-196

Sawrey, B.A.(1990). Concept Learning versus Problem Solving: Revisited. Journal of Chemical Education. Vol.67, No.3 pp.253-254

Yarroch, W.L.(1985). Student Understanding of Chemical Equation Balancing. Journal of Research in Science Teaching. Vol.22, No.5,Pp 449-459

Misconceptions of Misconceptions of Chemical Concepts in Chemical Concepts in

African ContextAfrican Context

Study Questions:

What misconceptions do grade 10 and grade 12 students held?

To what extents do the misconceptions differ within and between grade 10 and grade 12 students?

Areas of Study:

Concept Studied Reference Litrature 1. Solutions Nekhleh (1992), Wandersee (1994), and

Fensham, et al (1994). 2. Macro and micro-properties Temechegn, 2002; Mulford, 1996;

BenZvi etal, 1986 3. Mole Cervellati et al, 1982; Novick, S. &

Menis.J.1976 4. Particulate nature of matter Mulford, 1996;Grifiths and Preston,1992;

Gabel et al, 1987 5. Conservation of mass Mulford 1996; Bodner, 1991 6. Equation and Stoichiometry Lythcott, 1990; Sawrey, 1990;

Nurrenbern & Pickering, 1987; Yarroch, 1985; Kolb, 1978

7. Changes of state Mulford, 1996; Osborne & Cosgrove,1983

8. Gas Mulford, 1996

Subjects:

Sample Size:G 10 -163 students - 48 % F total of 329G 12-166 students - 35 % F

The average age:G 10 = 16.6 years and G 12 = 17.6 years

Background: Both groups took chemistry as a separate subject since grade 7

Schools data were collected:(Addis Ababa)

Grade 10 (N=163)

Grade 12 (N=166)

Name of General

Secondary School, G10

Number of Participants

Name of Preparatory

School, G12

Number of Participants

1 Kokebe Tsibah 35 1 Addiss Ketema 34

2 Lem 29 2 Keftegna Arat 31

3 Medhanialem 35 3 Medhanialem 35

4 Menelik II 33 4 Menelik II 33

5 Wondiyirad 32 5 Wondiyirad 33

Techniques of data analysis:

SPSS/version-9

• Descriptive statistics: Mean, Standard Deviations and Percent

• Test for significance:t- test

ANALYSIS AND INTERPRETATION OF FINDINGS A. Solutions

1. Figure 1 represents a 1.0-L of sugar solution. The dots in the

magnification circle represent the sugar molecules at a very smallportion. In order to simplify the diagram, the water molecules have notbeen shown.

Figure 1 Figure 2 Which response represents the view of the same portion after 1.0 L of

water were added Disappear 36 molecules 6 molecules 12 molecules 24 molecules

(a) (b) (c) (d) (e)

12 molecules

…… Solutions• Percentage distribution:

N a (%) b(%) c(%) d(%) e(%)

Grade Grade Grade Grade Grade Grade

(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q# 1 161 162 14.9 16.7 14.9 6.2 26.7 32.1 15.5 25.9 28.0 19.1

• Comparison t321 = -1.062, p < 0.289 ;Not Statistically significant difference at .05 level.

• Response comparison with other study

Alternative Conception (Responses)*

Mulford's Study, 1996

(Australia)

Present Study (12th grade)

2003 (Ethiopia)

6 molecules-correct response 75% 32%

B. Macro versus Micro properties

Q.1 A copper wire has the following properties:i: Conduct electricityii: Reddish coloriii: Combines with oxygen to form Cupric Oxideiv: All of the above properties v: None of the above properties

Which of these properties would be the same for one single atom of copperobtained from the sample?

(a) i (b) ii (c) iii (d) iv (e) v

• Percentage distribution:

N a (%) b(%) c(%) d(%) e(%) Grade Grade Grade Grade Grade Grade

10 12 10 12 10 12 10 12 10 12 10 12 161 165 25.5 21.2 13.7 8.5 20.5 28.5 34.2 33.7 6.2 9.1

• Comparison:t324 = -1.678, p < 0.094; Not Statistically significant difference at .05 level

C. Mole

Q1. Which of these three sets contains equal mole of Tin (Sn), Magnesium (Mg), andSulfur (S)?

(a)

(b) (c) (d) All of the above. (e) None of the above.

100 g of Sn 100 g of Mg 100 g of S

100 atoms of Sn 100 atoms of Mg 100 atoms of S

100 cm3 of Sn 100 cm3 of Mg 100 cm3 of S


N a (%) b(%) c(%) d(%) e(%)


(Q#)

10 12 10 12 10 12 10 12 10 12 10 12

Q# 1 157 164 10.8 7.3 27.4 40.9 14.6 9.1 33.8 23.8 13.4 18.9

• Comparison:t319 = -2.559, p < 0.011; Statistically significant difference at .05 level.

………….MoleQ2. Which of the following represent 1 mole of a substance, at STP (Standard

Temperature and Pressure)?a. 22.4 dm3 (L) solid carbon dioxide.b. 22.4 L liquid carbon dioxide.c. 22.4 L gaseous carbon dioxide.d. All of the above.e. None of the above.



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q# 2 161 163 3.1 1.8 22.4 17.8 31.7 41.7 36.0 34.4 6.8 4.3

•Comparisont322 = -1.879, p < 0.061 ; Not Statistically significant difference at .05 level.

D. The Particulate Nature of matter

Q1. What would ultimately be found if you divide and subdivide a drop of water into smaller and smaller parts, without destroying the water itself?

a. it will disappear.b. it can be divided with out limit (indefinitely).c. can be reached at a point where division is impossible.d. a drop of water is so small that it can’t be divided.

• Percentage distribution N a (%) b(%) c(%) d(%) e(%)

Grade Grade Grade Grade Grade Grade 10 12 10 12 10 12 10 12 12 10 12 10

160 165 15.0 7.9 30.6 25.5 33.8 44.2 20.6 22.4 - -

• Comparison:t323 = -1.943, p < 0.053; No statistically significant difference at .05 level

………….The Particulate Nature of Matter

Q2. What is the approximate number of carbon atoms, assuming placed side by side, that can cover a length of 1cm,

a. 10-1,000 carbon atomsb. 1,000 –10,000 carbon atomsc. 10,000-100,000 carbon atomsd. 1,000,000-20,000,000 carbon atomse. 40,000,000-50,000,000 carbon atoms

• Percentage distribution N a (%) b(%) c(%) d(%) e(%)

Grade Grade Grade Grade Grade Grade 10 12 10 12 10 12 10 12 10 12 10 12

153 151 30.1 21.2 30.1 21.2 18.3 19.2 7.2 10.6 14.4 27.8

• Comparison:t302 = -2.903, p < 0.04; Statistically significant difference at .05 level

………….The Particulate Nature of MatterQ3. Draw a liquid after the solid melts and draw a gas after the liquid boils.

Melts Boils

Solid Liquid Gas

Description: • Summary of the responses [using Gabel, et. al. (1987) criteria]

Grade 10 Grade 12 Criteria L G L G

Conservation of particles • Conserved 41.32% 31.71% 55.57% 53.47%

Proximity of particles • Far apart to one another relative to

solids 99.10% 100.00

% 79.26% 100.00

% • Far apart to one another relative to

liquids 73.64% 79.26%

Orderliness of Particle arrangement • Disordered (relative) 41.07% 60.71% 66.67% 78.68%

Location of particles in container • Bottom of the container 58.92% 6.72% 59.70% 2.16% • Evenly distributed through out 39.29% 93.28% 39.55% 94.24% • Top of the container 1.79% 0.00% 0.75% 3.6%

Constancy of particle size • Constant (the same) 88.68% 82.73% 91.61% 89.29%

E. Conservation of mass

Q1. What is the mass of the solution when 1 kilogram of salt is dissolved in 20 kilograms of water?

a. 19 kilograms. b. 21 kilograms.c. 20 kilograms. d. Between 20 and 21 kilograms. e. More than 21 kilograms.



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q#2 161 163 12.4 4.3 41.6 58.3 21.1 14.7 21.1 17.2 3.7 5.5

• Comparison:t322 = -3.033, p < 0.003; Statistically significant difference at .05 level.

…………Conservation of mass

Comparison with other studies

Alternative Conceptions (Responses)

Mulford's Study (1996)

Present Study Grade 12

19 Kilogram 1 % 4 % 21 Kilogram 72 % 58 %

20 Kilogram 11 % 14 %

Between 20 and 21 Kilogram

15 % 17%

More than 21 Kilogram 1% 6 %

• Comparison:

Comparatively students in Mulford’s study performed better than the present study.

…………Conservation of massQ2. Iron combines with oxygen and water

from the air to form rust. If an iron nail were allowed to rust completely, one should find that the rust weighs:

(a) less than the nail it came from. (b) the same as the nail it came from. (c) more than the nail it came from. (d) it is impossible to predict.

Q3. What is the reason for your answer in question 3? a. It decomposes to other materials. b. It forms an oxide but the weight

remains constant. c. The weight of oxygen can vary from

place to place. d. Rust contains iron and oxygen.

•Comparison:Q2* t322 = 1.144, p < 0.253; Not Statistically significant difference at .05 level.Q3** t320 = -1.647, p < 0.101; Not Statistically significant difference at .05 level.



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q# 2 161 163 28.0 34.4 21.1 25.8 35.4 30.1 15.5 9.8 - -

Q# 3 161 161 27.3 27.3 24.2 24.2 18.6 9.9 29.8 38.5 - -

…………Conservation of massComparison with other studies:

• Response comparison with other similar study for question #2 and #3

Responses Grade 12 of the present

study

Mulford’s study (1996)

Australia Percentage of students responded choice-c to question #2

30%

46%

Percentage of students responded both #2(c) & #3(d)

26%

44%

N.B In this study both responses and reasons which are in line with the

conceptions held by the scientific community were found to be less compared with Mulford’s study.

…………Conservation of massQ4. When a match burns in a closed

container, some matter is destroyed. Is this statement true or false?

a. True b. False

Q5. What is the reason for your answer in question 4?

(a) Chemical reaction causes mass to disappear.

(b) Matter is consumed by the flame. (c) The mass of ash is less than the

match it came from. (d) The atoms are not destroyed,

they are only rearranged. (e) The match weighs less after

burning.

• Comparison Q4* t322 = -3.179, p < 0.002; Statistically significant difference at .05 level.Q5** t319 = -4.089, p < 0.000; Statistically significant difference at .05 level.



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q#4 161 163 64.0 46.6 36.0 53.4 - - - - - - Q#5 158 163 23.4 12.9 17.7 17.8 15.8 4.3 28.5 50.3 14.6 14.7

F. Equations, and Stoichiometry

Q 1. The diagram represents a mixture of H2 and O2 molecules in a closedcontainer.

Hydrogen gas Oxygen gas

Which diagram shows the product (water molecules) after the mixturereacts according to the equation?

2H2 + O2 2H2O

(a) (b) (c) (d) (e)

…….. Equations, and Stoichiometry



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q# 1 160 163 14.4 19.0 11.3 2.5 20.6 41.7 20.6 14.7 33.1 22.1

• Comparisont321 = -4.185, p < 0.000 ; Statistically significant difference at .05 level.

…….. Equations, and Stoichiometry

Q2. The reaction between reactant X( ) and reactant Y ( )is shown inthe following diagram.

Based on the above diagrams, identify the equation that can bestdescribe the reaction?

(a) 3X +Y6 X3Y6 (b) X3 +6Y 3X6Y (c) 3X + 3Y2 3XY2 (d) 3X +6Y 3XY6 (e) 3X +6Y 3XY2



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q# 2 161 166 25.5 10.8 16.1 9.0 30.4 40.4 12.4 3.6 15.5 36.1

• Comparisont325 = -4.359, p < 0.000 ; Statistically significant difference at .05 level.

G. Changes of StatesQ1. Assume a beaker of pure water has been evaporated completely in a closed

container. What is the composition of the vapor?(a) Air. (b) Oxygen gas and hydrogen gas. (c) Water. (d) Water, hydrogen and oxygen.(e) Heat.



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12

Q# 1 163 165 15.3 4.2 44.2 57.0 11.0 15.2 22.7 17.0 6.7 6.7

•Comparisont326 = -1.101, p < 0.272 ;Not Statistically significant difference at .05 level.

• Response comparison for question #1 of the present study with other studies

Comparison-1 Comparison-2 Alternative Conceptions

(Responses) Osborne and Cosgrove

(1983) Late high school

(Age16)

Present Study

10th grade (Age~16)

Mulford First year

college(1996) (Age~17)

Present Study

12th grade (Age~17)

Air ~27% 15.3% 5% 4.2% Oxygen gas and hydrogen gas

~45% 66.9% (44.2+22.7)

55% (43% + 12%)

74.0% (57.0+17.0)

Steam (Water or Water vapor)

~27% 11.0% 38% 15.2%

Heat ~1% 6.7% 2% 6.7% Shaded = Currently accepted by the scientific community

………Changes of States

……. Changes of States

Q#2. The circle on the right of picture-1 shows a magnified view of a versmall portion of liquid water in a closed container. What would thmagnified view on the right of picture-2 show after the wateevaporates?

Picture-1 Picture-2

Which of the following diagrams represent the magnified view onthe right of picture-2 show after the water evaporates?

(a) (b) (c) (d) (e)

…… Changes of States



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q# 2 160 165 10.0 9.1 16.9 14.5 36.9 23.6 23.1 31.5 13.1 21.2

• Comparisont323 = -1.935, p < 0.054 ;Not Statistically significant difference at .05 level.

…… Changes of States

• Response comparison of written question(Q#1) versus pictorial (Q# 2)

Grade 10

Grade 12 Alternative conception

(Response)*

Written (Q# 1)

Pictorial (Q#2)

Written (Q# 1)

Pictorial (Q#2)

Air 15.3% Not Asked 4.2% Not Asked Oxygen gas and Hydrogen gas

44.2% 10.0% 57.0% 9.1%

Water 11.0% 13.1% 15.2% 21.2% Water, Oxygen and Hydrogen 22.7% 16.9% 17.0% 14.5%

Oxygen and Hydrogen Not Asked 23.1% Not Asked 31.5% Heat 6.7% Not Asked 6.7% Not Asked Disappears Not Asked 36.9% Not Asked 23.6%

Shaded = Currently accepted by the scientific community

…….Changes of StatesQ3. A glass of cold Coca-Cola forms a coat of water on the outside of the glass (Often

referred to as 'sweat'). How does the water get there? a. Water vapor condenses from the air. b. Water evaporates from the Coca-Cola and condenses on the outside of the

glass. c. The glass acts like a semi-permeable membrane and allows the water to

pass. d. The coldness causes oxygen and hydrogen from the air combine on the

glass forming water. e. The carbon dioxide found on the coca cola mix with the air when we open

the bottle and it forms water droplets.

• Comparisont320 = -.285, p < 0.776 ;Not Statistically significant difference at .05 level.


N a (%) b(%) c(%) d(%) e(%)


(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q# 3 159 163 10.1 11.0 10.7 8.6 13.8 8.6 35.8 39.9 29.6 31.9

H. GAS

1. A 1.0-gram sample of solid iodine is placed in a tube and the tube is closed after all of the air is removed. The total weight of the tube and the solid iodine is 27.0 grams. The tube is then heated until all of the iodine evaporates and the tube is filled with iodine gas. What will be the total weight after heating?

a. less than 26.0 grams. b. 26.0 grams.c. 0.0 grams. d. more than 28.0 grams.e. 27.0 grams.



(Q#)

10 12 10 12 10 12 10 12 10 12 10 12 Q# 2 162 161 13.6 10.6 24.1 15.5 17.9 9.9 12.3 7.5 32.1 56.5

Q# 3 159 159 28.9 52.5 23.3 10.8 22.6 19.6 13.2 8.2 11.9 8.9

Q#1 t321 = -3.022, p < 0.003 ;Statistically significant difference at .05 level.Q#2 t315 = -4.392, p < 0.000 ;Statistically significant difference at .05 level.

Percent response for both question #2(e) and 3 (a)*Grade 10 = 20% ; Grade 12= 45%

2. What is the reason for your answer in question #1? a. The only change is in the physical state of the

substance.b. Weight of solids is greater than gases. c. Iodine after evaporation becomes weightless. d. Pressure increases and as a result the total

weight increases. e. Only the mass of the tube remains.

Grade 10

Grade 12

Remark 80 % 70 % Can’t estimate correctly the size of the atom

66 % 56 % Believe matter is continuous

80 % 70 % Can’t distinguish between the properties of a single atom of copper and a copper wire

73 % 75 % Wrongly conserve number of moles and number of molecules during chemical reaction

54 % 42 % Can’t conserve mass during solution formation

65 % 70 % Students believe that the rust weighs less than the iron it came from

64 % 47 % Believes matter is destroyed when a match burns

73 % 59 % Students can’t associate the mole exclusively with

the number of particles

68 % 58 % Can’t restrict the molar volume at STP to gases

79 % 58 % Can’t differentiate subscripts and coefficients, and has an additive view of a chemical reaction

70 % 74 % Believe that water breaks into its component during evaporation

75 % 65 % Believe that gases contracted on cooling;

55% 36 % Believe that gases are weightless

28 % 19 % Students doubled concentration of a solution when

it is diluted by a factor of two

Summary

Conclusions:

1. The study indicated that majority (>50%) of G10 and

G12 do not master the chemical concepts studied.

2. Comparison:

G12 students difference is not significant in majority of the concepts compared to G10 Comparative

Correct response

In Present study Correct Concepts are low compared to other studies

Recommendations: Based on the finding the following recommendations are made:

1. Research should focus to try to retrace the possible rootcauses to the misconceptions found in this study. Thepossible root causes can be found in:

Student textbooks

Chemistry curriculum

Methodology

Age

The teachers

Motivation Evaluation

th d

Background/Prior knowledge

Learning conditions

Instructional materials

…………… Recommendations

2. Next after identifying the root causes research should

be done to bring about conceptual Growth:

• This opportunity must be taken in order to introduce changes in thecontents, methods and assessment of chemistry teaching.

3. Teachers, Curriculum developers, Text book writersshould:

• Be encouraged to actively search (Identify) for students' alternative

conceptions attempt to design teaching/ learning, which builds onrather than ignores such conceptions.

Thank You Very Much

Vielen Dank

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