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1 Printed in the Republic of Korea w 3w yû x w w w Á x* w w w yw ( ) A research of the Difference in Teaching Styles and Understanding of 9 th Grade Students About Lead-iodide Precipitation Reaction Experiment Sun-Ja Jeong and Seong-Hey Paik* Won-Il Middle School, Ansan city, Kyung-gi Do, , Korea Department of Chemistry Education, Korea National University of Education, Chung-Buk, , Korea (Received March 14, 2006). e y w» w w yû x w ƒ eš. w w 3w w w ƒ». 3 ww w, A w ww x mw w šwš ü w ww. B C x ü w w v w w w. A w x š Bù C w. ù Bù C w w šƒ w w. w wš x mw ww w œm ùkþ. w w j y» ö, mw e ww ùkû. : e, yû, w 3w w, w w, w,, w, x ABSTRACT. In this study, the teaching methods of three science teachers for lead-iodide precipitation reaction experiment were compared. The difference of 9th grade students understanding was searched according to the science teachers teaching styles, also. Among the three teachers, Teacher A taught students based on the science textbook and allowed students to think themselves and to get out conclusion by the experiment. Teacher B and Teacher C gave students a lot of explanations related to interpretation of the experiment. The percentage of no response on the experiment report of Teacher A was higher than those of Teacher B and Teacher C. But the students of Teacher B and Teacher C tended to have limited thoughts because of the teachers explanations. In spite of the difference, it was common phenomenon that few students understood concepts through the experiment. A lot of students were interested in the experiment, but it was hard to understand Law of definite proportions according to the experiment. Keywords: Law of definite proportions, Lead-Iodide precipitation reaction, 9th grade students, Understanding of students, Science teacher, Teaching style, Science textbook, Experiment 374

2 w 3w yû x w w w 375 ú w ù wù w sw ü w š w w ew w w z wš 1. Abraham 2 ƒ yw wš š, ƒ yw wš, yw w w w j w, xy ù m ƒ e ü w w. x ¾ w 3-11 ww w (, ) k w ù, ü w ew ƒ mw w., w 3w l ƒ ƒ, ü w, w w g ƒ š. w w š w w ü w. w ù w w w. w w ƒ w w, ½ y 12 Ÿx 13, š w w w yw w. x 14 w w ü w w š w š w ù, w y üsw w w w w w. š w w w» w w y wwš, w ü w w y» w w w š w. 15 w 3w yw l ƒ ƒ, š ƒ e w ƒ e wš w, ƒ š e ƒ w w wƒ w, ƒ e w. x 7 w w 3w ü l x mw x e z w mw. ù yû x mw e w w w ƒ ù w w. e w w w l w w w w w w w wwš š w w œw š ƒw ƒ e w» w, k, yw yû wš. yû k e w, w x» w š w š w. y û x y w» mw, e ³e k w w w v ƒ. 16 mw yû e x ƒ ³e w ³e q w ƒ š w. w x w e x w ƒ x mw e ww ƒ. w ü w ƒ e ƒ w w w» w ü w ü w. x x 17 š w 1w w wš,, w

3 376 Á x w, w ü w q, ü ¾, ü j x. Veal w wš w ü w. w w ü w ƒ, w ƒ w w w e w v w. w,. ƒ. yû x w ƒ ƒ? ù. yû x z w w ƒ?» w w w 3w w û 117, w. w w wš w w w w. w w Table 1. w ƒ w w ûw w, w w w, w x yw. yw p w, x w, x w» ƒ w x, x p ƒ w,,,, ƒ p w ü w. x š x t,» t v, w w ƒw x,» x, w ù y d, x w ª w w w ƒ w. w ù w w. x w ww x û 6ml x ye 0, 2, 4, 6, 8, 10 ml yû d w. x ye ƒw» ƒ ƒ w ƒ ù ƒw w w wš, mw w ƒ w w e ü» w. 16 w x ³e. ù x x ƒ ƒ w, ƒw x mw ü w j y. x ùkù w w yw w» y û ù yû w. p w l ƒ w» ƒ» š, w w w w. w k Table 1. Characteristics of the three teachers Teacher A B C Major Chemistry Physics Biology Career period Sex Female Female Female Degree Master Master Bachelor

4 w 3w yû x w w w 377 û ù yw xk e y yû x wš, ye ù û š e w w x w w. ù yû x v w w. ww œm w ü Table 2 w. œm x x w wš, x w. š x ü w š, x w üw. ù. B C x ww» v w w, ey x, w w w. ù A w x ww. A ü x w v w w, ey, w ù e w x ww. B x w v w x mw ü w e w ü x w. C x w v w w ù, x l w w e w w. A B xw w w w w ü y w ù, C w w š x ww. x w v w e w ü w B 8 ƒ ¼., ù w w A 3 ƒ. ù x ww ƒ w wš, x w sw j ü A B w. A x w š w ƒw w. yû x ww ù w y mw,», w y w. ww, w x w» x ww. A ye Table 2. The characteristics of the three science teachers teaching styles Common feature Different points Teacher A Teacher B Teacher C Experimental procedure Teachers representation Teachers representation Teachers representation Experiment style Group Group Group Experiment contents Based on the science textbooks Based on the science textbooks Based on the science textbooks Introduction 3 minutes 8 minutes 4 minutes Representation 37 minutes 30 minutes 38 minutes Completion 5 minutes 7 minutes 3 minutes Teaching contents Emphasis of experiment results No explanation of law of definite proportions No explanation related to interpretation of the experiment results The change of precipitation amount Explanation of law of definite proportions Explanation of dissociation, substitution, dissolution of salts, etc. The change of precipitation amount No explanation of law of definite proportions Explanation of dissociation, substitution, dissolution of salts, etc. No emphasis

5 378 Á x ƒw ù, l w w š w w, x ƒ ù w x ƒ ù w w. ù š w w ƒw w w. B, e? wš ƒ ww, ww ù ww w ƒ w. w ƒ w.. š w. w x w v w w. ye wš û ye e ƒ w š û û w ƒ w š û ù yû š e û? e w š kƒ.». w w» l ƒ ¾ w w k» ƒ š. B w yw txwš, w w ƒ ww txw. w w tx w w š w e ƒ. B ù û w ƒ š, ù e w š kƒ, w w w. ù w ƒ w w w w ƒ š» (w ) ù x wš w yw ww w ƒ., ñ (y» ) ww w» w x w w w j w ƒ. B x ƒ wš, mw ye 0ml, 2ml, 4ml, 6ml, 8ml, 10ml û w ƒw w. t. A-F¾ x û š ye, û ù yû û š ƒ ƒ ƒ? ƒ? wù wš ÿ? ü. B x š w w w wùwù w. w e. û. B ƒ w yw w»» Í ƒ» w.î š w. yw txwš. w w w B ƒ x w w. tx w, j ƒ š w ù, ƒ ww š

6 w 3w yû x w w w 379 txw ƒ. ù w š w w tx w w š w. l w e y w» w yû kw w š w. l w w, w x w yw». š ƒ w w w B z û w t xw š w txw» w. 7 ye ƒ g ƒ w, ƒ w ƒƒ w š û. ƒ w ƒ ƒ w ƒ w š û. ƒ û ¾? ye û ¾ û û ¾? ƒ. ƒ ƒw,. B w w w yw ƒ š», w š w š w w txw w š ywš w. ù w w ù w v w w w ƒ w.» x w v w v w», w w j ƒwš w x w ƒ w. C B w w. ye e, e š w. w,? š?? w. w w 3w w š q wš, š w. š w, w ù w w e w. ù ñ ww û w w» wš w. ye e ù š û û ù ã, û û š w, ww ƒ š ù e ù w w, w? w.,. ƒ? e. ù w e». š w w? š ww w ùkü. š w w w, e w ww wš,? w. w w w w ww w y, C û w yw w w š û e

7 380 Á x Table 3. The students responses according to the teachers Number of response (%) Response type Teacher A Teacher B Teacher C Total Type 1 * Nitrate, Potassium, Lead 13(16.3) 12(12.5) 10(10.0) 115(16.3) Type 2 Potassium Nitrate 21(26.3) 74(92.5) 77(96.3) 172(71.6) Type 3 Remained atoms 15(16.3) 11(11.3) 10(10.0) 116(12.5) Type 4 No response or the others 41(51.2) 13(13.7) 13(13.7) 47(19.6) * Correct answer w w. w û k z û w w» ƒ. C A w w x š ƒ w w š w w. x š mw w w ƒw x w ƒw x w w w Table 3 w. ƒw y k ye y û w yû x w. û ye e û û. x 1 w š w. w ù w yw ƒ š w,,, w w ù e û w kƒ w yw x k w e,, û ƒ x 1 w. A x û w š w, w š w š w. š w w y w y w š, x 1 w 16.3% w. B x û w w š, C x ü w w š š e. š w. x wš û w x w û, û w. w w š w e Table 3 mw y w. B C w 90% w e, y e û š w, û û š w w ùkû. x w w ùe w šw x mw z w ww y w. ù A 51.3%ù w w w. ƒ x v w w w š ww, yû x mw w q wš mw e y w» x. ùe ùe y ƒ w w w w w v ƒ š ƒw. ƒw x w ye ƒ g

8 w 3w yû x w w w 381 Table 4. Students responses about the materials of solution in the test tube Number of response(%) Response type Teacher A Teacher B Teacher C Total Type 1 * Iodide, Nitrate, Potassium 17(21.3) 14(17.5) 8(10.0) 139(16.3) Type 2 Potassium Nitrate 17(18.8) 44(55.0) 69(86.3) 120(50.0) Type 3 No response or the others 56(70.0) 22(27.5) 13(13.8) 181(33.8) * Correct answer ƒw x w w ƒ Table 4 w. û w y ye ƒ g, y, e y š û y w», y, e w š ƒ w w. w w yw» y e, e yw xkù,,, w xk w x 1 w. Table 4 Table 3 w ƒ ùk û. w w w A w 70% w w w w. ù x 1 w B, C w. B, C w x wš û š wš, ƒ w y š w w 55-86%. w ùkù y d û y jš, ye v w w xw w w ƒ w Table 5 w. x y j š j w. ã w w wwš w. ä ƒ š w, x w q wš w š w. w w» w x w» š w, x wš wš w w wwš x w x w w. ù x wwš, y j ë w š dw w 40%. š ù 60% w ƒ ùkú š dw ù w ƒ txw w. w p, w ƒ ùkû. w yû mw q w y w. Table 5. Students anticipation about the result of reactants exchange Number of responses(%) Response Teacher A Teacher B Teacher C Total Type 1 * Similar result 27(33.7) 34(42.5) 35(43.7) 96(40.0) Type 2 The amount of participation is different. 23(28.8) 29(36.2) 40(50.0) 92(38.3) Type 3 The amounts of participation of the all test tube are same. 17(18.8) 16(17.5) 11(11.3) 14(15.8) Or all of the amount are different. Type 4 There is no participation. 15(16.3) 15(16.3) 10(10.0) 10(14.2) Type 5 No response or the others 18(22.4) 16(17.5) 14(15.0) 29(11.7) * Correct answer

9 382 Á x Table 6. Students questions after the experiment Type Participation (232) Procedure of experiment (54) Compound, bond, or dissociation (29) Content Teacher A Teacher B Number of response Teacher C Why is the participation yellow? How make the other color participation? Why the amount of participation is not change any more? Why the participation form? Why the participation glitter? Why the participation sink? The state of the participation is solid? Where the participation is used? What happen if I exchange the process of the two solutions? What is the method participation sink fast? Is there a relation between amount of participation and temperature? Can I see the bonding process of Iodide and Lead directly? What is the meaning of the height of participation? Why the amount of Potassium Iodide solution increase in the experiment? Other solutions also react according to the raw of definite property? Why specific elements make bond when some compound mix with other compound? Why Potassium and Nitrate make participation? Lead Iodide compound has the properties of Lead and Iodide? What kind of reaction occurs when two materials don t melt in water? Total x z w ª x ww z x w ª w ù š w, (Table 6). š w w» w w t xw š w. w j w, x w, š yw w, w w x w. ù p. w w ª ƒ 232 ƒ. w n w»w ƒw, ùkü w w. p ƒ wš ª w w w,, k, ª w w w. yû w y» w» z. ù ¼¾?,» š w ¾? r, w x» ww w e ùkù q w wš. ù, yw w, w w w w. y w yw ù w ö ww yw ¾?, e ¾? w» w ww wš ùkü. x w w ¾? š» w w w w w w w w w w. w ƒ?,, ƒ ù?, y, y e ù? mw w x ww wš

10 w 3w yû x w w w 383. x ww w, w w. e w ww ³e w. y û w ƒ w (1), w w (2), š wù ƒw wš yw l ö ww w (3) sw. yû w x w w x š w. w w š y û x w w w wù. mw e y w» w w yû ƒ eš. w w w ƒ». 3 ww ƒ», w x mw š w w w. ù œm w x w wš ww j ùkû. w ƒ w w, w w w wš x ü w w, x ww v w ƒ w w xw ù, y ƒ w š w ùkû. w 3w w ü w ww w, w wš z ùkü w w d r v ƒ. yû x e w y j» w w x, ª l e mw l w w j. ù yû ye y j w yƒ w y j w w w ye y j x ww. l ù y š mw ye w v w. k ƒ, e l w x, ã l ƒ wš, yû x mw y w x x k. ù x»» l w x w. w» wš, l yû x w ö w w x ww w qw ƒ. w r ³e w v p ù l e w, š yû mw w ³e y wš, w ³e ùkù ƒ w e k. x ª, w k jš x mw z wš w w w w w š w. ù yû mw r, x ü w w ww w x d z ƒ j.

11 384 Á x w ³e ü e w x mw z w» w x ü v w š. x 1. «x. w w ü w š. w w w Abraham, M. R.; Grzybowski, E. B.; Renner, J. W.; Mark, E. A. Journal of Research in Science Teaching. 1992, 29(2), ;. w w wz. 1995, ½ ; ½ ; y;. w w wz. 2004, 24(5), ½ ; ; «; y;. w w w z. 2005, 25(7), ; ½. w w wz. 1993, 13(2), «ù. w w w y w p w. w w w w k. w p n w e w. w w w w «e ; x ; y; ½. w w wz. 2004, 24(6), ; š. w w wz. 2004, 24(5), ³ ; x; ½x ; û». w w wz. 2001, 21(1), ½ y..š w w w yw. w w w x. wywz, 2004, 48(1), Ÿx..š w w w yw :,, y,,. w w w w 3w yw ƒ e w, w w w w w. w w w w yw x w. w w w x; x., 2005, 21(3), Veal, W. R. Journal of Curriculum and Supervision, 2003, 18(4),