Chemical Education Journal (CEJ), Vol. 12, No. 1 /Registration No. 12-3/Received September 20, 2008.
URL = http://chem.sci.utsunomiya-u.ac.jp/cejrnlE.html

Pre-laboratory Visualization Techniques to Support Learning and Teaching of Introductory Chemistry Laboratory

 

Tawfik A. Saleh*

Department of Chemistry,
King Fahd University of Petroleum and Minerals,
Kingdom of Saudi Arabia

*Email: abo_nor1hotmail.com

 

Abstract

The purpose of this study was to investigate the effect of using pre-laboratory visualization resources as a technique combined with pre-laboratory assignments in teaching and learning general chemistry laboratory. The research was conducted during one year, three semesters. A comparison statistical analysis of the grades of both control and experimental groups showed that this technique is significantly better. t-test is higher than the critical values. Effect size indicates that the performance in this technique is more than 35 percentile points higher than the control group. Experimental groups of students gained better understanding of the concepts and had better technical-skills acquisitiveness. Based on the research findings, pre-laboratory visualization techniques are recommended to be used in combining with pre-laboratory assignments in teaching and learning general chemistry laboratory.

Key words: pre-laboratory visualization, pre-laboratory assignment, first-year undergraduate, general, chemical education,

Introduction
Problem Statement
Laboratory Description
Viewing Procedure
Design of the Survey Form
Data Collection
Evaluation
Results and Discussion
References

Introduction
Virtually, every student who seeks a bachelor's degree in science or engineering must pass the general chemistry course; class and laboratory. It is important that general chemistry be an attractive introductory experience. Chemistry laboratory is used to provide students with chemical techniques as well as to support students understanding concepts. In chemistry education, most teachers use traditional pedagogical methods. However, learning a subject by practice or repetition is enhanced by thinking about and observing others performance (Oxendine, 1968). One of the most important key in laboratory teaching is to prepare students' minds for learning new concepts as well as new skills. Over the years, students have been and still are mentally prepared by the traditional short lectures presented at the start of the laboratory period, demonstrations, reading assignments, graded quizzes, and other pre laboratory assignments. The pre lab technique has undergone changes over the years. Out of pre laboratory activities reported in the literature are writing assignments (Pickering, 1987), addressing common mistakes made in the lab (Jacobsen, 1995; Zimmerman, 1996) and pre lab cooperative learning (Fleming, 1995).

Since 1970, CD-ROM began to appear in the literature ( Kempa, 1975; March, 2000). Pantaleo showed that videotapes shorten in-lab instruction (Palma, 1975). Russell, in 1985, did a comparison study between videotapes and videodiscs instructions in a freshman laboratory class and showed that using the videodisc as a pre-laboratory activity enhanced significantly the enthalpy experiment (Russell, 1985). The use of computer assisted learning (CAL) has also been reported in the determination of the percent oxygen in a sample of potassium chlorate (Moore, 1980); in four organic chemistry experiments (Wiegers and Smith, 1980).

In this study, pre-laboratory visualization techniques have been investigated. This paper starts with the statement of the problem followed by experimental description and design. Then, it highlights the data collection and evaluation, followed by discussion of the results.

Problem Statement
Here, at King Fahd University of Petroleum and Minerals (KFUPM), pre-laboratory assignments have been used for along period of time. However, it was noticed that students, either are not interested or face difficulty solving the pre-laboratory questions, especially questions related to the practical aspects. This can clearly be attributed to the fact that students have not performed the experiment, and have not seen the equipments or dealt with. Recently, there was a shift into the pre-laboratory graded quizzes; however, there was no significant improvement. To prepare students' minds for learning new concepts as well as new skills, I believe that pre-laboratory visualization techniques can be combined with this to help student visualize the experiment and prepare their mind to perform the experiment. Visualization plays a major role in science education, in teaching and learning of science at any level in educational systems.

Laboratory Description
The general chemistry course at KFUPM is designed for most freshmen, science and engineering majors. The control and experimental laboratory groups were designed to give students pre-laboratory assignments and graded quizzes.

 

Viewing Procedure
In the experimental groups only, students were given access into the WebCT in which videos, photographs, pictures and some brief instructions of each experiment were uploaded, consecutively. Students were asked to review the material and prepare to have a quiz and to perform the experiment. On the other hand, students of control groups were not given access.

Design of the Survey Form
The survey forms were designed in three parts. In the first part, students were asked if this technique was complementary to pre-laboratory exercises. Also, they were asked how this technique effected there performance. In the second part, they were asked if this technique was helpful in preparation and performance. In the last part, they were asked in which stages of the lab work this technique can be preferable used.

Data Collection
Data collection was designed to provide information about academic performance of both control and experimental groups. In addition, questionnaires were distributed to experimental-students. Excel and MINITAB software were used for analyses.

Evaluation
The evaluation of the pre-laboratory visualization learning techniques consisted of two parts: the statistical comparison analysis of the quizzes and report sheets grades of the experimental and control groups during two semesters, and the other part is the analysis of students' attitudes.

Results and Discussion
The goal of the pre-laboratory visualization techniques was to prepare students for the laboratory experiments. To measure the effectiveness of this strategy, a comparison was conducted between the laboratory performance of the pre-laboratory visualization users (experimental group) with the performance of sections of students who had not used pre-laboratory visualization resources (control group). The pre-laboratory visualization users did significantly better on the pre-laboratory written quizzes, the experiments and the final (Table 1). This is clear from the statistical results; t-test is higher than the critical value in the three parts. P-values are less than 0.05. In addition, we calculate the effect size (Bowen, 2000) for the three parts according to the following equation:

The effect size indicates that pre-laboratory visualization techniques can significantly enhance student efficiency and understanding. An effect size of 1.15 (Table 1), means that median students' performance is significantly improved from the 50th percentile in the control sections, to approximately 87th percentile in the pre-laboratory visualization users (Table 2).

Table 1. Statistics on Pre-laboratory Visualization Achievement
   Experimental Group  Control Group  Statistical Values
 Mean  S.D.  Mean  S.D.  t-test (critical value at P= 0.05)  p-value  Effect size*
 Written Quizzes  70.4  1.3  68.6  1.7  10.1 (3.18)  0.002  1.05
 Experimental Reports  87.1  2.91  78.9  7.13  3.69 (2.22)  0.004  1.15
 Final  89.3  2.7  84.0  3.9  4.42 (3.18)  0.02  1.36
* See table (2)

Table 2. Effect Sizes and Percentile Changes between Treatment and Control Groups

 Effect Size

  Percentile Standing

1.4
1.3
1.2
1.1
1.0
0.8
0.6
0.4
0.2
0.0

91.9
90
88
86
84
79
73
66
58
50

* (Cohen, J. 1988)

Students were asked to fill out survey forms that included statements to which they could agree or disagree. When asked how they found pre-laboratory visualization recourses, students agreed that pre-laboratory visualization was a good tool to solve pre-laboratory exercises and graded quizzes (Table 3.). They agreed also that pre-laboratory visualization was a good tool to prepare students' minds for learning new concepts as well as physical skills. It was a good technique by which motivation, efficiency and effectiveness of students were increased. They agreed also that this technique demonstrated a set of technical observations in interesting way. Students could review the resources at any time at any place. When they were asked how pre-laboratory visualization recourses helped them, students agreed that pre-laboratory visualization helped them better acquire technical skills, and to avoid laboratory accidents (Table 4.).

Table 3. Students' Responses to How they Found Pre-Laboratory Visualization:
   I found that pre-laboratory visualization resources:  % A  % D
 1.  were complementary to pre-laboratory exercises  85  15
 2.  gave me some sort of excellent mental preparations  100  0
 3.  improved my performance , skills and abilities  82  18
 4.  increased my independence and motivation  67  33
 5.  increased the efficiency and effectiveness of discussion  85  15
 6.  were a good tool to demonstrate a set of observations  79  21
 7.  presented experiments within an interesting context  79  21
 8.  gave chance to review the material at home, at any time that is appropriate to me  100  0
*A: agree, D: disagree

Table 4. Students' Responses to How Pre-laboratory Visualization Helped them:
   I believe that pre-laboratory visualization resources helped me:  % A  % D
 1.  prepare for the quizzes and experiments  85  15
 2.  understand the experiments' contents  79  21
 3.   reduce down the fair and hesitate dealing with the experiments and chemicals  67  33
 4.  understand how to conduct the experiment  73  27
 5.  perform accurate measurements  79  21
 6.  understand how to use some chemical equipments  76  24
 7.  understand the safety regulations  85  15
 8.   follow the recommended precautions  79  21

Table 5. Students' Responses to How Pre-laboratory Visualization Can be Used:
   How can pre-laboratory visualization be used?  % A  % D
 1.  As a preparation prior to students practical  94  6
 2.  As a preparation tool prior to an instructor demonstration  91  9
 3.  As tools that help students solving the pre-laboratory exercises  79  21
 4.  As a substitute for an experiment due to student's absence.  53  47
 5.  As a revision resource since they can be revisited quickly as many times as I wish and at a time and place convenient to me  94  6
 6.  As a plenary when the experiment has not been successful in yielding the expected observations.  70  30
 7.  As tools for the safety regulations and recommended precautions  82  18
 8.  As tools for the exam preparation  73  27

As to how pre-laboratory visualization can be used, students agreed that pre-laboratory visualization can be an excellent way to prepare for the experiments and exams, to understand safety regulations and recommended precautions (Table 5.). It is helpful when students have failed to complete the practical work, or have had insufficient time to understand the concept of what takes place. Sometimes, practical work does not yield the expected results or observation for one reason or another. In such cases pre-laboratory visualization techniques can be a useful tool to demonstrate perfect observations. In other cases, students can catch up experimental work when they have missed the laboratory due to absence. From a "safety" point of view, pre-laboratory visualization techniques can be a good way for students to learn. Since good laboratory practices are observed, the recommended precautions can be followed.

As a result of the availability of pre-lab resources, students can visualize the experiment before lab attendance. This gives them good idea of how to perform the experiment and lead to improve creativity and analytical thinking.

 

References
Bowen, Craig W. (2000). "A Quantitative Literature Review of Cooperative Learning Effects on High School and College Chemistry Achievement" J. Chem. Educ., 77, 116- 120.

Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Lawrence Earlbaum Associates.

Fleming, F. F. (1995). "No Small Change: Simultaneously Introducing Cooperative Learning and Microscale Experiments in an Organic Lab Course" J. Chem. Educ., 72, 718.

Jacobsen, J. J.; Jetzer, K. H.; Patani, N.; Zimmerman, J.; Zweerink, G. (1995). "Propylene Oxide Addition to Hydrochloric Acid: A Textbook Error" J. Chem. Educ., 72, 612-613.

Kempa, R. F.; Ward, J. F. Br. (1975). "The effect of different modes of task orientation on observational attainment in practical chemistry" J. Educ. Technol, 5, 62-71.

March, J. L.; Moore, J. W.; Jacobsen, J. J. (2000). "ChemPages Laboratory: Abstract of Special Issue 24 on CD-ROM" J. Chem. Educ., 77, 423-424.

Moore, C.; Smith, S.; Avner, R. A. (1986). "Facilitation of laboratory performance through CAI" J. Chem. Educ., 57, 196-198.

Oxendine, J. B. (1968) "Psychology of Motor Learning" Appleton-Century- Crofts: New York.

8Palma, R. J. (1975). "A technique-oriented freshman laboratory program" J. Chem. Educ., 52, 116-117.

Pickering, M. (1987), "What goes on in students' heads in lab?" J. Chem. Educ. 64, 521-523.

Russell, A. A.; Staskun, M. G.; Mitchell, B. L. (1985). "The use and evaluation of videodiscs in the chemistry laboratory" J. Chem. Educ., 62, 420-422.

Wiegers, K. E.; Smith, S. G. (1980). "The use of computer-based chemistry lessons in the organic laboratory course" J. Chem. Educ., 57, 454- 456.

Zimmerman, J.; Jacobsen, J. J. (1996). "Quantitative Techniques in Volumetric Analysis" J. Chem. Educ., 73, 1117.

References (in the order of appearance)
1. Oxendine, J. B. (1968) "Psychology of Motor Learning" Appleton-Century- Crofts: New York.

2. Pickering, M. (1987), "What goes on in students' heads in lab?" J. Chem. Educ. 64, 521-523.

3. Jacobsen, J. J.; Jetzer, K. H.; Patani, N.; Zimmerman, J.; Zweerink, G. (1995). "Propylene Oxide Addition to Hydrochloric Acid: A Textbook Error" J. Chem. Educ., 72, 612-613.

4. Zimmerman, J.; Jacobsen, J. J. (1996). "Quantitative Techniques in Volumetric Analysis" J. Chem. Educ., 73, 1117.

5. Fleming, F. F. (1995). "No Small Change: Simultaneously Introducing Cooperative Learning and Microscale Experiments in an Organic Lab Course" J. Chem. Educ., 72, 718.

6. Kempa, R. F.; Ward, J. F. Br. (1975). "The effect of different modes of task orientation on observational attainment in practical chemistry" J. Educ. Technol, 5, 62-71.

7. March, J. L.; Moore, J. W.; Jacobsen, J. J. (2000). "ChemPages Laboratory: Abstract of Special Issue 24 on CD-ROM" J. Chem. Educ., 77, 423-424.

8. Palma, R. J. (1975). "A technique-oriented freshman laboratory program" J. Chem. Educ., 52, 116-117.

9. Russell, A. A.; Staskun, M. G.; Mitchell, B. L. (1985). "The use and evaluation of videodiscs in the chemistry laboratory" J. Chem. Educ., 62, 420-422.

10. Moore, C.; Smith, S.; Avner, R. A. (1986). "Facilitation of laboratory performance through CAI" J. Chem. Educ., 57, 196-198.

11. Wiegers, K. E.; Smith, S. G. (1980). "The use of computer-based chemistry lessons in the organic laboratory course" J. Chem. Educ., 57, 454- 456.

12. Bowen, Craig W. (2000). "A Quantitative Literature Review of Cooperative Learning Effects on High School and College Chemistry Achievement" J. Chem. Educ., 77, 116- 120.

13. Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Lawrence Earlbaum Associates.

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