PBL approach in web-based instruction.

Web-Based Instruction is increasingly being recognized as a means of teaching and learning. In dietetics, the interactions between drugs and nutrients are complex due to the wide variety of drugs and their mechanism and interactions with nutrients. How to help student professionals acquired necessary skills and knowledge is important in a dietetic training program. This paper proposed an integrated problem-based learning (PBL) approach in a web-based context to help students acquire knowledge. Important aspects of the PBL framework such as the use of problem sets, instructional contents, basic knowledge, exploration, facilitator, and scaffolding were discussed. The application of the PBL approach to a web-based instruction was implemented and evaluated. Students' responses were gathered from different aspects, including: instructional functions, use of resources, use of discussion, and assignment.

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PBL has been adopted for the preparation of professionals in fields as diverse as medicine, engineering, law, and business. Its characteristic focus on the presentation of authentic cases as the starting point for learning has substantially enhanced the students' motivation to learn and augmented their ability to integrate knowledge from foundation disciplines in pursuit of a solution to practical professional problems (Albion & Gibson, 2000).

The main objectives of PBL are to develop the skills of self-directed learning, professional reasoning, and decision-making within an easily retrievable knowledge base. This task-oriented approach organizes the curriculum around a series of cases profiling dilemmas of practice, which student professionals read, diagnose, discuss and explore strategies for solving these problems.

The PBL approach emphasizes on experiential learning organized around the investigation and resolution of messy, real-world problems. Web-based technology can be used as a powerful tool for locating and organizing information, and a means of delivering and presenting a solution. The use of Internet can be considered as a way of "foraging for information or targeted hunting for specific information" in a PBL approach (Sage, 2000).

Several examples have shown successful integration of web-based technology with PBL, where students were provided with opportunities to use the Internet to search problem solution as well as to contact experts (Milbury & Silva, 1988; Sage, 2000). Using Internet has potential impact on students' experience of learning in a PBL environment in terms of electronic cooperation (Reznich & Werner, 2001). Particularly in science, mathematics, and social studies, students were inspired to learn, and organize visually their growing and changing understanding of the problems (Sage, 2000).

In light of enhancing students' necessary skills and knowledge in PBL, students are provided with opportunities to gather and analyze information about their topics, compare other cases with the specific attribute of their own problem, and develop a best-practice approach to the task (Harwell & McCampbell, 2002). Students are encouraged to take responsibility for their projects, develop a suitable plan, and use the Internet as a research and problem-solving tool that allows information to be retrieved quickly to facilitate discussion among members and synthesis of knowledge.

With the advent of web-based learning technology, students are facing new change in perceiving knowledge and setting new goals to manage today's world knowledge. The integration of PBL approach in solving realistic problems might add potential enrichment to a web-based instruction. Specifically, the purposes of this research were to (1) develop a web-based instruction employing PBL to enhance students active learning,, (2) study how students perceive and experience in the PBL approach of web-based context, and (3) evaluate the learning in terms of instructional functions, use of resources, use of discussion, and assignment.

Instructional Approach

To educate nutrition-major students become eligible dieticians, it is essential to help students understand various drug and nutrient interactions. Consistent with the constructivist perspective, learning is the contention of knowing and doing. To provide the real-life experience, the web-based learning was arranged around the framework of problem themes. Participation in an activity was aimed to help students experience learning and understanding.

Instructional setting and subjects

Subjects participating in this study were 56 college students enrolled in the course Drug and Nutrient Interaction. They were undergraduate students majored in food and nutrition, and were being trained to become dieticians. Drug and Nutrient Interaction was an elected course offered to junior students every other semester. The course aimed to acquaint students with the various interactions between drugs and nutrients, which they might encounter in the hospital when dealing with their patients.

In this study, clinical cases as a design scenario were used to explore the PBL experience in web-based instruction. Students signed up as a team of 5-6 persons for their choice of ca se study according to their interest. The web-based instruction, Drug & Nutrient Interaction (http://pbl.lins.fju.edu.tw) taught online was provided for learning. The presentation of course contents contains animations, still pictures, and textual information to enhance understanding of the mechanism of drug and nutrient interactions.

To encourage active participation in PBL teaming and to foster web-based interaction, students enrolled in the course were required to register, learn the instructional content, complete the assignment, and use the discussion column to communicate and exchange views with other group members about the final project.

PBL approach

Consistent with the constructivist perspective, learning is the contention of knowing and doing. Participation in an activity can help students experience learning and understanding (Brown, Collin & Duguid, 1989). Web-based learning activities were carefully planned and integrated in the course. To provide a PBL experience, the course activities were organized around the framework of problem themes. A task-oriented approach was employed to encourage students' active participation of learning. Several components that constitute PBL learning were identified as described in the following.

Problem Sets: Ten clinical cases were used as the problem theme that allowed students to interact with. These clinical cases contain drug-nutrient interactions most frequently found. In the problem sets, students were encouraged to analyze the cases from different perspectives using various resources. The use of problem cases was pre-shaped by authoritative resources. Students could sort among the divergent perspectives and conflicting priorities in any complex situation of practice, and think and act in ways that allowed a flexible view of a situation that would accommodate emerging details. Figure 1 shows a problem example used in the web-based instruction.

[FIGURE 1 OMITTED]

Basic Knowledge: Given the current debate regarding the use of PBL as the exclusive means of learning, the basic knowledge provided by the web-based instruction was designed to correspond closely with the problem sets. The course content included: "introduction to drugs", "mechanism of drug actions", "effects of nutrients on drug metabolism", "effects of drugs on nutrient metabolism", and "consulting techniques on drug and nutrient interactions". The organization of the instructional content is shown in hypertext structure on the screen, appearing as a 'Table of Content'. With this, students could easily access different lessons by clicking on the hyperlinks provided.

Exploration: Besides providing guidelines for preparing the final projects, the website also offers links to various medical databases in order to enable students to explore further into the related fields. Students were taught how to access information from various medical databases and resources from government agents, academic institutes, and public/private organizations. Through the hyperlinks to various information resources contained in the instruction, students were able to use the Internet to explore different learning contents pertinent to their research focus. Participants were able to gather information about their research topic, compare other cases to the specific attributes of their own problem, and develop a plan to accomplish their task.

Facilitator: In the study, each group was assigned to an online facilitator (an anonymous senior student who had taken the course before). The responsibility of a facilitator was to help the groups engage in their own discussion and learning. They set up brainstorming strategies, encouraged constructive evaluation of the contribution of each member, and kept track of the students' discussion to ensure that they were working towards the objectives of the course. When the group became more independent in carrying out their own discussion (one or two weeks later), the facilitator withdrew from active participation to become a quiet observer. This was to ensure that he/she would not override the focus of the group.

Peer Interaction: The class was divided into 12 groups. Students had responsibility toward their group members. In the learning setting, each student could act as an "expert" resource person, who provided clarification, personal anecdotes and summarized important concepts, which broadened the learning experience. Students could provide relevant information they had found, while other group members could aid in critical appraisal of the resourced obtained. Thus, each student had the responsibility to exploit his/her area of expertise and became a valuable learning resource for the others.

Scaffold Learning: In the PBL approach, scaffold learning was fostered through the frequent interaction between the instructor, students, and facilitators. The instructor and facilitators provided formative evaluation and offered comments on the overall performance and progress of each group. For groups to function effectively, the instructor and facilitators challenged and assessed critically students' learning and online discussion. They provided constructive and continuous evaluation of how the students approached learning issues and the quality of information students gathered. Under the guidance of the instructor and facilitators, students could achieve successful knowledge construction.

Evaluation

Data were collected to reflect the students' participation of the web-based PBL activities, including (1) discussion messages and (2) questionnaires, and (3) oral responses from the teacher, facilitators, and students. To keep track of the work progress among the members, each group owned an online discussion column, where they could reflect on the problem sets, identify and discuss the resources they found, and divide the responsibility for accomplishing the project. The messages posted on the discussion columns also served as a means for content analysis to help identify instructional problems and learning obstacles among the students.

The questionnaire used to examine students' reactions toward the web-based activities and PBL learning contents contains four major categories of items, namely instructional functions, use of resources, use of discussion, and assignments. The Likert's five-point scale was used, where 1 indicates strongly disagree and 5, strongly agree. Descriptive information about the web-based learning experiences was also gathered from the instructor, facilitators, and students.

Results

Group discussions

Messages posted by the 12 groups for online discussion were gathered. Excluding those from the instructor or facilitators, a total of 842 messages were posted. The degree of involvement in online discussion among the 12 groups varied. The content of students' discussion can be grouped into the following categories: (1) Topic Selection: messages about choosing a research topic for their final project, (2) Resources Posting: messages about identifying and sharing available articles found from related websites, (3) Project Content Discussion: messages about discussing the contents of their final projects, and (4) Others: messages of casual chat, reflections, and questions about the course content. Table 1 lists the total number of messages in each category. Students' interaction about preparing their final projects is not just limited to the online discussion. There was also face-to-face discussion, where communication could be more effective. For example, through group meetings, they divided the work among team members, selected appropriate resources, and decided on the content of the final report.

Web-based evaluation questionnaires

A questionnaire containing 42 items was used to assess students' affective responses toward the web-based PBL activities. Fifty-six participants filled out the questionnaire. The reliability test using Cronbach's alpha coefficients is 0.92 for the 42 questionnaire items. Cronbach's alpha coefficients for different response categories (including: instructional functions, use of resources, use of discussion, and assignment) are listed in Table 2. Tables 3-6 are the evaluation results of these categories.

Table 3 shows the results of items 1-10 evaluated for the major functional areas. As shown in the table, most students were more positive about the instructional objectives, interface design, organization, easy-to-use, lesson contents and future expectations. The means of items, items 1, 2, 4, 5, 6 and 10, respectively, are > 4.0. Table 4 reveals the 10 evaluation items (items 11-20) for use of resources. Among these items, students agreed more on items 15 (learning from the instruction extends their knowledge), and 19 (the related resources allow them to explore the topic of their interest actively).

Table 5 displays the students' reaction toward the use of online discussion (items 21-32). Comparatively, students agreed more on item 27 only (in-depth analysis of the problem) (mean for item 27 > 4.0; means for the rest items < 4.0). Although over 800 messages were posted on the 12 columns, most students might find it easier to communicate with each other face-to-face.

Items 33 to 42 probed into the reactions of student toward the use of assignment (final project). As seen in Table 6, students agreed with most of the items in this category. Average points on items 34, 35, 36, 37, 39, 41 and 42 greater than 4.0 reveal the positive reaction towards the use of task-oriented approach. The assigned task was to extend the students' observation of a problem, and help them realize how to apply learning in a realistic environment. From the PBL experience, students were provided with opportunities to analyze cases, assign responsibility among team members, and search related information. Students also agreed that the PBL approach helped them learn how to explore a problem and the skills they had acquired could be transferred to learning other areas of knowledge.

Discussion

From a constructivist perspective of teaching and learning, the traditional roles of a teacher and a student change significantly in PBL. Students are expected to shoulder greater responsibility in learning, while teachers become resources or tutors, guiding students in their problem-solving efforts (Ayres, 2002). To get involved in the instructional tasks, students started with the problem scenarios, interacted with the instructional contents, and selected the topic or issue for research. Results obtained by the web-based evaluation questionnaire shows that students found all the 42 reviewed items agreeable (means > 3.0). They agreed strongly to some of the items, especially those in the category of "Assignment". Students' reactions reflect strong agreement on the use of task-oriented approach in studying an issue of their interest.

Students learn better and remember longer when the learning is active and meaningful (Mierson & Paikh, 2000). Construction of knowledge counts not only on the content and meaning of the gathered information, but also students' management of the amount and form of information (Marcum, 2002). Examining the overall responses from the four categories of items reveals that the use of discussion was the least agreeable among students (mean = 3.66). In addition to online discussion, integrating different modes of interaction is needed, especially for clarifying complicated issues in a problem set. The use of face-to-face interaction was considered an essential component to foster management of information and conceptual understanding of knowledge among groups.

From the study, the variation in students' involvement in the process of reviewing and selecting appropriate information was observed when performing the instructional task. The web-based learning tool also served as a means of monitoring students' progress and involvement in participating the learning activity. A note from the instructor reveals that training of facilitators for coaching students' progress is essential. To see real growth in students' critical-thinking skills, PBL should be used as a regular organizing strategy in the classroom--not as a one-shot strategy. Facilitators need to be trained to alert the instructor to students' potential obstacles and problems. They also need to be familiarized with the use of various resources and databases in order to help students employ appropriate strategies to gather relevant information and evaluate resources collected.

Conclusion

In summary, this research explores the theoretical and practical issues of using PBL in web-based instructional design. On the theoretical aspect, this study raises the issues that constitute the use of PBL in a web-based approach. On a practical level, we conclude that the use of PBL achieves its intended purpose of fostering more meaningful learning. With the task-oriented approach, students learned necessary skills and synthesized knowledge. However, the application of PBL to other web-based designs merits further investigation.

Table 1
Types of message gathered from twelve discussion columns

             Topic     Resources    Content
Group      Selection    Posting    Discussion   Others   Total

Group 1        26          28          26         22      102
Group 2         6          43          23          9       81
Group 3        12          45          15          1       73
Group 4         9          53          11          2       75
Group 5        11          19          21          5       56
Group 6        10          92          34          5      141
Group 7        12           6          20          4       42
Group 8        19          28          24         21       92
Group 9         3          43          47         13      106
Group 10        7           2           8          2       19
Group 11        3           9           6          2       20
Group 12        8          16           9          2       35
Total         126         384         244         88      842

Table 2
Cronbach's alpha coefficients of questionnaire (n = 56)

Item Category             Cronbach's alpha coefficient

Instructional Functions   0.76
Use of Resources          0.93
Use of Discussion         0.78
Assignment                0.77
Total                     0.92

Table 3
Evaluation results for instructional function (n = 56)

                       Response Item                           Means

1.  I can easily identify the learning objectives from the     4.10
    website.
2.  The interface of the website is easy to use.               4.23
3.  The screen design of the website is attractive and         3.54
    arouses my interest.
4.  The instructional materials provided on the website are    4.04
    well organized.
5.  I can browse the learning content through the entire       4.06
    website easily.
6.  The lessons provided on the website help me learn.         4.08
7.  I can learn the course at my own pace.                     3.75
8.  Participating in the web-based learning activities helps   3.96
    me monitor my own progress.
9.  Participating in the web-based learning activities         3.63
    encourages me to learn actively from the instructional
    materials.
10. I hope more of this type of instruction can be developed   4.25
    in the future.

                         Total Mean                            3.97

Table 4
Evaluation results for use of online resources (n = 56)

                       Response Item                          Means

11. I often browse the resources provided on the website to   3.65
    get related information.
12. The resources provided on the website are very useful     3.81
    to me.
13. The links to related websites help me identify more       3.94
    learning resources.
14. The connections to online database allow me to search     3.98
    the information of my over interest.
15. Learning from the web-based instruction extends my        4.42
    understanding of related

Table 5
Evaluation results for use of online discussion (n = 56)

                       Response Item                           Mean

21. The group discussion activities can arouse my motivation   3.79
    in exploring knowledge
22. I participated actively in the online group discussion.    3.69
23. The group discussion helped us clarify the problems we     3.94
    explored
24. I often reviewed the discussions from our own group.       3.71
25. I enjoyed having online conversation with peers.           3.19
26. I enjoyed discussing with my group members.                3.19
27. From our group discussion, I learned how to have an        4.02
    in-depth analysis of the problem.
28. The group discussion can reflect the involvement of our    3.94
    group members.
29. From the group discussion, I learned ideas from our        3.85
    group members.
30. I often reviewed discussions from other groups             3.25
31. Browsing discussions among peers is helpful in learning    3.83
    the content area.
32. Browsing discussions among peers is helpful in knowing     3.46
    how to communicate with others.

                         Total Mean                            3.66

Table 6
Evaluation results for use of assignment (n = 56)

                       Response Item                           Mean

33. The assigned task allows me to relate real experience      3.92
    with learning content.
34. The assigned task extends my observation of the problems   4.17
    from different areas.
35. The assigned task helps me realize how to apply my         4.23
    learning in a realistic setting.
36. From the problem situations provided, I had analyzed the   4.23
    cases from different possible perspectives.
37. To accomplish the assignment, we assigned tasks for each   4.02
    group member.
38. The web-based activities encourage me to cooperate with    3.71
    other team members.
39. Through accomplishing the web-learning task, I learned     4.23
    to search related information to solve the problems.
40. From the web-learning activities, I learned how to         3.98
    synthesize information and report what I had learned.
41. Through the web assignment, I learned to explore a         4.29
    problem actively.
42. The skills I have acquired from the activities can be      4.25
    transferred to learning other related subject areas.

                         Total Mean                            4.11

Acknowledgement

This paper was originated in a project supported by a grat form the National Science Council (NSC 90-2520-S-030-001) whose financial support is gratefully acknowledged.

References

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Lih-Juan ChanLin, Department of Library and information Science, Fu-Jen Catholic University, Taiwan. Kung-Chi Chan, Department of Food & Nutrition, Providence University.

Correspondence concerning this article should be addressed to Lih-Juan ChanLin, Department of Library and Information Science, Fu-Jen Catholic University, Taiwan; email: [e-mail]