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Teaching with Technology
Gabriela C. Weaver
Achieving Greater Feedback and Flexibility Using Online Pre-Laboratory Exercises with Non-Major Chemistry Students
Purdue University West Lafayette, IN 47907
Gail D. Chittleborough* Faculty of Education, Deakin University, Burwood, Victoria 3125, Australia; *
[email protected] Mauro Mocerino Department of Applied Chemistry, Curtin University of Technology, Perth, Western Australia 6845, Australia David F. Treagust Science and Mathematics Education Centre, Curtin University of Technology, Perth, Western Australia 6845, Australia
This paper reports on the design and effects of using online pre-laboratory exercises in an introductory first-year university chemistry course that assumes no previous knowledge of chemistry and is designed for non-major chemistry students. The Importance of Laboratory Work Laboratory work provides students with opportunities for the integration of knowledge in a meaningful way (1). However, laboratory work is often criticized for not being relevant to the coursework, and being a recipe task in which the students simply follow the instructions without understanding what they are doing (2). Consequently, along with factors of cost, safety, and time, the importance of laboratory work in chemistry has been contested in recent years (3). The importance of pre-laboratory preparation is crucial considering that what students already know determines what they will learn (4). Indeed, research has shown that students’ attitude towards chemistry is enhanced when the laboratory activities are related to the theory being studied and when the rules of behavior expected in the laboratory are clearly outlined (5, 6). The working space in the brain is limited; Johnstone (7) is critical of the overload that instruction in laboratory manuals can demand, forcing students to adopt a recipe-like procedure. The technical, unfamiliar language often used in laboratory manuals puts additional demands on students’ short-term memory reserves (8). This situation is particularly true for inexperienced, non-major university chemistry students. Robinson (9) believes that symbolic representations in the form of visual images in laboratory manuals can assist students’ understanding. This view is supported by Dechsri, Jones, and Heikkinen (10) who reported improved student performance in the cognitive, affective, and manipulative domains of the laboratory as a result of including pictures and diagrams with the text. Pre-Laboratory Exercises Laboratory activities should develop students’ skills in experimental techniques such as observing, classifying, using laboratory equipment, as well as applying conceptual 884
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knowledge, developing procedural knowledge, and applying inquiry tactics such as identifying variables and interpreting data (11). The need to work at these various levels simultaneously is demanding, even for major chemistry students. Preparation is one way to ensure that the students maximize the benefits of the introductory chemistry class. Laboratory work is a compulsory component of this firstyear introductory chemistry course. Students must attend at least 80% of the laboratory classes and complete the laboratory work to a satisfactory standard. The laboratory manual provides detailed written instructions on the weekly laboratory work, although it is printed in an economical format that lacks illustrations and diagrams. The expectation was that students would read and understand the required pages from the laboratory manual before arriving for the laboratory class. The laboratory manual serves all the first-year university courses for both major and non-major students. The students mostly do the same experiments because of the logistics and economics of equipment and chemicals. Despite their ability to follow written instructions, the non-major students’ understanding of the aim of an experiment is sometimes obscured by the tasks required to conduct the experiment. The authors proposed that a more thorough preparation for the laboratory class would improve this situation. The pre-laboratory exercises have targeted those aspects that have been shown to affect learning particularly for nonmajor chemistry students. A previous study (12) with a similar cohort of non-major chemistry students identified characteristics that could constrain students’ understanding of chemistry, including: students’ level of appreciation of chemical representations and diagrams; the students’ prior knowledge in chemistry and mathematics; students’ lack of motivation to understand chemistry at a deeper level; and students’ poor time management in completing necessary tasks. With the reduced cost of technology and greater accessibility, there has been a large increase in the use of online resources at all levels of education. Economic factors, perceptions and expectations of students and administrators have driven this trend often without assessing the educational value and merit of such resources. The term “online learning” is used loosely and somewhat presumptuously, whereas the term “online resources” may be more appropriate and accurate,
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with the learning being that which occurs in the learner, not in the computer. In light of this difference, the analysis of data will be discussed in terms of the impact of the online pre-laboratory exercises on the students’ perceptions of their learning of chemistry and the appropriateness and suitability of using an online learning forum. The objective of introducing online pre-laboratory exercises was to have students identify the aim of the weekly experiments, to show students pictures and diagrams of unfamiliar equipment, to outline the methods and the sequence of events, to encourage students to read the laboratory manual more carefully, and to promote students’ confidence in the subject. In addition, students could use the additional resources available through the online facility such as the solutions to typical tests, e-mail, and the discussion board. The aim of this study was to address the research question: What is the impact of the online pre-laboratory exercises and resources on students’ learning in the introductory chemistry course? Educational Design and Context The students involved in this study are described as “nonmajor” chemistry students because they are not intending to continue in chemistry after their first year of university studies. This is compared to “major” chemistry students who have completed chemistry to a high level at high school and are studying chemistry courses at university for a period of at least three years. Nevertheless, the non-major students are completing a science degree and are required to master a minimum level of chemistry. The non-major students are enrolled in degree courses for environmental biology, health sciences, human biology, and environmental health. Responding to the needs of the non-major chemistry students, weekly online pre-laboratory exercises were imple-
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mented to better prepare students for the weekly experiment and provide basic information for students with little or no chemical background. Students were required to access, complete, and submit their answers to the pre-laboratory exercises electronically prior to the laboratory class each week. The exercises are deliberately designed to be straightforward and uncomplicated, endeavoring to help the students understand the practical and theoretical aspects of the experiment and to provide positive feedback. The online pre-laboratory exercises were designed to take approximately 10–20 minutes per week to complete and were worth 2% of the students’ final grades. Even though the value of the task is very small, it is compulsory and designed to be a learning opportunity rather than an assessable task. Students are asked an average of eight questions each week, in formats including multiple-choice, short-answer, and matching. The Web-based assessment provides students with immediate feedback. The correct answers are positively reinforced; hints are given when students answer incorrectly, thus helping them identify misconceptions. An example question and the feedback for each alternative response are shown in Textbox 1. The desired outcomes of this project were to improve links between theory and practical work and provide immediate feedback to students, suggesting reasons for their incorrect choice as well as reinforcing correct answers and instilling confidence in their abilities. This instructional strategy was designed to encourage a positive learning environment without the pressures of assessment and to provide an avenue of communication with other students and staff. With multiple opportunities to do the pre-laboratory exercises, students receive feedback on their responses and thereby have an opportunity to reflect on their understandings. Students were initially given three opportunities to do the pre-laboratory exercises when the data were collected: this has now been reduced
Textbox 1. Example of a Pre-Laboratory Exercise with Feedback Why should a constant, minimum amount of indicator be used in titrations? (Question 5, Semester 1, Week 4)
Alternatives (Possible responses)
Reasons (Feedback for corresponding responses)
Indicators are expensive and should be used sparingly.
Incorrect. Many indicators come from common plants and other natural sources. The success of the titration is dependent on having the right indicator. Indicators provide evidence that the equivalence point has been reached.
A lot of indicator must be used to ensure the change is observed.
No, it is better to have enough indicator to see the color. Use white paper for contrast. Indicators provide evidence that the equivalence point has been reached.
To ensure constant color intensity.
Correct. Indicators provide evidence that the equivalence point has been reached. It is best practice to use the same amount of indicator for each titration.
The amount of indicator used does not matter.
No, it is better to use the same amount of indicator in each titration so that the results can be compared. Indicators provide evidence that the equivalence point has been reached.
General Feedback Indicators provide evidence that the equivalence point has been reached. It is best practice to use the same amount of indicator for each titration.
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to two because there was concern that the task lost value and could be trivialized in allowing three attempts. The data indicate that students take the second attempt (Table 1) and value it as an opportunity to learn and improve their grade. The study was conducted at Curtin University over one academic year, involving 98 students (48% female and 52% male) in the first semester and 115 students (46% female and 54% male) in the second semester. Information on the use
of the online chemistry site and student responses to the online survey form the primary data sources in the study. The online survey was administered to investigate students’ opinions about using an online facility, the value of the pre-laboratory exercises, the additional online resources, and the impact on the experimental work. The survey consisted of 19 items, shown in Table 2, using a Likert scale of 1–5 where 1 was strongly disagree and 5 was strongly agree, as well eight
Table 1. Data Comparison of Students Completing the Pre-Laborator y Exercises for Semesters 1 and 2 Students, by Semester
Average Number a of Students per Week
Mean Score on Exercises (%)
Average Number of Attempts
Average Time Spent b per Test (min)
Average Time Spent b per Week (min)
Semester 1 (11 weeks)
088
83.2
1.7
10.2
17.6
Semester 2 (12 weeks)
103
87.7
1.9
07.0
13.4
aApproximately
90% of the students from the sample, on average, completed the exercises. with the test page open, not necessarily the amount of time spent taking the test.
bThis
is a measure of the time students were online
Table 2. Distribution of Student Responses to an Online Survey of Attitudes about Pre-Laboratory Exercises, by Statement Item
Statements for Response (N = 115)
Mean Scorea (SD)
Strongly Disagree, %
Disagree, %
Neutral, %
Agree, %
Strongly Agree, %
01
My computer skills are good enough to use the WebCT program effectively.
4.5 (0.8)
2
2
6
23
67
10
Being able to try an exercise more than once helped me learn from my mistakes.
4.4 (0.8)
1
3
6
36
54
09
Getting immediate feedback on the online pre-laboratory was valuable.
4.2 (0.8)
0
4
13
46
37
06
The online pre-laboratory exercises allowed me greater flexibility with my time.
3.8 (1.2)
6
10
12
39
33
12
I understood the experiments better having done the online pre-laboratory exercises.
3.8 (0.8)
0
8
23
52
17
13
The pictures and diagrams in the online pre-laboratory exercises were valuable.
3.8 (0.8)
0
7
23
53
17
07
The online pre-laboratory exercises provided feedback on my understanding.
3.7 (1.1)
6
9
16
52
17
08
The online pre-laboratory exercises helped me to learn and understand the concepts in the experiment.
3.7 (0.9)
3
8
19
56
14
11
I had to read the laboratory notes in order to do the online pre-laboratory exercises.
3.6 (0.9)
2
9
30
44
15
14
I use the solutions to the typical tests on the Web site regularly.
3.5 (1.2)
7
17
19
37
21
17
I usually completed the pre-lab exercises before the laboratory session.
3.3 (1.2)
9
17
22
36
16
16
I find the e-mail facility useful.
2.9 (1.0)
10
18
53
11
9
15
I monitor the discussion page on the Web site regularly.
2.7 (1.2)
21
29
23
20
7
18
I find the calendar useful.
2.7 (0.9)
10
23
53
12
2
02
Without good computer skills I could not use the pre-lab exercises effectively.
2.6 (0.9)
7
47
32
13
2
19
The Web site has directed me to relevant Internet sites.
2.6 (0.8)
10
33
49
7
1
03
I had difficulty accessing the Web site from home.
2.1 (1.1)
33
40
14
10
3
04
I had difficulty keeping the Web site up and running.
2.0 (0.9)
32
47
11
9
1
05
I had difficulty navigating the Web site for the unit.
1.9 (0.8)
34
53
8
4
1
a The instrument required students to indicate the extent of their agreement with the statements on a five-point scale where 1 = Strongly Disagree, 2 = Disagree, 3 = Neutral, 4 = Agree and 5 = Strongly Agree. Percentage frequency values have been rounded to whole numbers.
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questions that required written responses. Two examples of the questions requiring written answers are “What aspects of the pre-laboratory exercises are helpful to your learning of chemistry?” and “Do you think the pre-laboratory exercises are achieving their objectives?”. The results of the survey items investigating similar issues (including both Likert and written responses) were compared to ensure that the responses were consistent. Data on the frequency of use, mean score and number of attempts were used for cross-checking the survey results. Results and Discussion Students commented on the flexibility of being online, being able to learn at their own pace, getting immediate feedback, working problems out for themselves, having the opportunity to revisit problems and learn from their mistakes, forging links between the theory and practical course components, and building confidence in the subject. In brief, those factors identified by the data include: feedback, motivation, self-efficacy, organization, and utilization of online resources. Data supporting each factor are presented and discussed. Feedback The primary objective of the pre-laboratory exercises was to provide students with feedback on very simple concepts related to the weekly experiment. With 83% (Table 2, item 9) of students agreeing that “getting immediate feedback on the online pre-laboratory exercises was valuable”, and 90% (Table 2, item 10) of students agreeing that “being able to try an exercise more than once helped me learn from my mistakes”, the value of feedback and renewed opportunity appears to be appreciated. When asked about the value of the pre-laboratory exercises to their learning, in the written questions of the Online Survey, students’ replies supported the quantitative data. For example: • Getting immediate feedback, plus knowing that the right answer is there. If you get it wrong, makes it easier to work it out yourself.
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exercises helped students to build understanding and confidence in the subject: • The [pre-lab exercises] have certainly helped me to gain a better understanding of the labs when I go into the experiment having already completed the pre-lab questions. And I like knowing how well I understand each topic, so the feedback is extremely helpful in that sense. • This is the first time that I have done any chemistry, and I have to admit that the first semester was a chore, and I did not enjoy it. However, this semester, I have gained my confidence in the lab, and through the structure of the unit I am actually enjoying it. • I personally benefit from WebCT as I can access it from home. It gives greater flexibility to my time and helps me clear doubts I have during my course of learning. • In labs, I feel more confident as a result of doing prelab exercises and reading hints.
The comments about confidence and preparedness, as well as those referring to understanding the content, provide some insight into the importance of the students’ self-efficacious beliefs about their learning. Organization Many students (59%) agreed that the pre-laboratory exercises forced them to read the laboratory notes (Table 2, item 11) and the majority of students agreed (72%) that the online nature of the pre-laboratory exercises allowed them greater flexibility with their time (Table 2, item 6). The written responses support these results, for example: • Yes. It’s a help cause you do them as they are worth marks and this forces me to learn. • Yes, if you do these pre-labs before the lab you get a better understanding of what to do in the lab instead of wasting time trying to think what to do. • I think that the pre-labs are an excellent idea as they force you to think about the lab before you go, you know you are getting the correct information and saves the instructors some explaining in the lab.
• Yes—when studying at home it is hard to know if your understanding is correct without assistance from the lecturer. With WebCT I can see straight away where I am going wrong and focus on that area.
The time restraints imposed by the pre-laboratory exercises force students to maintain a regular effort.
• The ability to do it in your own time, the immediate feedback, multiple goes at each one.
Utilization of the Online Resources
These responses reveal students’ perceptions of their learning and show that many students are interested in learning and understanding chemistry, and in appreciating the role of feedback in the process of learning. Motivation and Self-Efficacy The responses to items in the online survey provide support for the social–affective perspective of learning. For example, with the majority of students (70%) agreeing that “the online pre-laboratory exercises helped me to learn and understand the concepts in the experiment” (Table 2 item 8), the students’ perceived benefits are apparent. Supporting this perspective are indicative examples of the students’ written responses that demonstrate the claim that the pre-laboratory www.JCE.DivCHED.org
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Although the pre-laboratory exercises were worth only a very small percentage of the students’ final grades, many students took advantage of the opportunity to redo the exercises and improve their score, as is seen in the average number of attempts (Table 1) of 1.7 and 1.9 for semester 1 and 2, respectively. The mean score for the pre-laboratory exercises was 83.2% and 87.7% for each semester (Table 1). This high score is in line with the objective of the exercises to give the students confidence and to help them learn from their mistakes. The exercises were designed to take only 10–15 minutes, aiming for regular positive reinforcement, and to better prepare the students for the laboratory session. The results of 17.5 minutes per week for semester 1 and 13.4 minutes per week for semester 2 spent by students completing the exercises are consistent with this objective.
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Having to access the Web site regularly to complete the online pre-laboratory exercises meant that students could become more familiar with the additional resources available on the Web site. The online survey results indicate that 58% of students agreed that they used the solutions to the typical tests on the Web site regularly (Table 2, item 14). This is confirmed by a typical written comment from the online survey: • The typical test solution showing the workings has been extremely helpful in LEARNING, not only getting the answers, as each problem has been set out step by step. [Emphasis in original]
The results indicate that the other facilities such as email, calendar, discussion, and links to Web sites were not valued so highly by the students. Even though many students did not post messages themselves, the data indicate that they did access the page to read what other students had written. Conclusion The survey results indicate that the majority of students involved in this study considered that their learning opportunities were increased by completing the online pre-laboratory exercises and using the online resources. The study has addressed the research question, “What is the impact of the online pre-laboratory exercises and resources on students’ learning in the introductory chemistry course?”. Survey results show that the majority of students believed the online pre-laboratory exercises were advantageous because they: • Allowed flexibility in time and location of taking the exercises • Provided feedback on both correct and incorrect responses • Provided opportunities to retake the exercises with no penalty • Prepared students better for the laboratory activities than the previous format of reading the laboratory manual • Provided exercises that targeted the level of understanding of the learner • Provided visual supplements
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The additional online resources were considered to be of mixed value, with the typical test solutions being valued by the majority of students, whereas the calendar, e-mail and discussion facilities were less valued by the majority of students. There are obvious advantages in using an online forum that can provide access for a large number of students to a variety of resources in a flexible manner. The students’ comments, however, indicate that the strength of the online forum was in providing feedback both through the pre-laboratory exercises and through the worked solutions to the typical tests. Students appreciated the feedback because it provided them with an opportunity to learn. Literature Cited 1. Hofstein, A.; Lunetta, V. N. Sci. Educ. 2004, 88, 28–54. 2. Gallet, C. J. Chem. Educ. 1998, 75, 72–77. 3. Nakhleh, M. B.; Polles, J.; Malina, E. Learning Chemistry in a Laboratory Environment. In Chemical Education: Towards Research-Based Practice; Gilbert, J. K., De Jong, O., Justi, R., Treagust, D. F., Van Driel, J. H., Eds.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 2002; pp 213–234. 4. Ausubel, D. P. Educational Psychology: A Cognitive View; Holt, Rinehart and Winston, Inc.: New York, 1968. 5. Wong, A. F.; Fraser, B. J. Res. Sci. Techn. Educ. 1996, 14 (1), 91–102. 6. Tsaparlis, G.; Gorezi, M. Canadian J. Sci., Math. Tech. Educ. 2005, 5, 111–132. 7. Johnstone, A. H. J. Chem. Educ. 1997, 74 (3), 262–268. 8. Gabel, D. The Complexity of Chemistry and Implications for Teaching. In International Handbook of Science Education; Fraser, B. J., Tobin, K. G., Eds.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 1998; pp 233–248. 9. Robinson, W. R. J. Chem. Educ. 1998, 75 (3), 282–83. 10. Dechsri, P.; Jones, L. L.; Heikkinen, H. W. J. Res. Sci. Teach. 1997, 34 (9), 891–904. 11. Garnett, P. J.; Garnett, P. J. Australian Sci. Teachers J. 1995, 41 (2), 26–32. 12. Chittleborough, G. D.; Treagust, D. F.; Mocerino, M. In Focusing on the Student; Bunker, A., Swan, G., Eds.; Professional Development@Learning Development Services: Perth, Australia, 2002; pp 43–5.
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