Editor’s Note: Simulation using interactive multimedia has long been recognized as a means of reducing time and cost for hands-on learning. This study shows how easy-to-use computer software can achieve these advantages, provide additional learning enhancements, and support distance learning.

Development and Evaluation of an
Interactive Multimedia Simulation on Electronics Lab Activity: Wien Bridge Oscillator

Chetana H. Kamlaskar

India

Abstract

Use of interactive computer simulation to impart complex educational content enables students to experience phenomena related to abstract scientific concepts and principles. Also, it allows students to explore change in the simulated model before making changes in real world situations. The objective of this research project is to ‘design and create’ an interactive simulation to ensure students’ preparedness to perform basic electronics lab activities in a real laboratory and observe circuit behavior by manipulating variables such as supply voltage, component values, etc. This computer simulation presents a step-by-step procedure of a simulated laboratory practice. Macromedia Flash MX 2004 is a tool used to build interactive simulations because it offers a high level of interactivity, cross-platform capability, multi platform delivery and scalability, ease of authoring, and superior audio capabilities.

This paper attempts to demonstrate how the interactive simulation was developed. It also presents a study that investigates the effect of using computer simulation for comprehension of a procedure and its relation to the theoretical framework. The findings from the study demonstrate that this simulation package is a useful educational tool for ‘learning by doing’.

Keywords: computer assisted learning, multimedia, elearning, electronics engineering, it use, higher education, computer simulation, practical learning support, distance learning
 

Introduction

One hallmark of an electronics engineering technology programme is that laboratory classes accompany most lecture courses. Laboratory procedures are essential learning experiences in engineering and technology education. They enhance instruction in engineering courses and develop knowledge and skill required for practicing professionals. In traditional education, the learner has direct access to well-equipped laboratories and assistance. Distance learners go to a study centre in their region to perform lab experiments with traditional equipment, devices, methods, and techniques for measurements, data recording, and result analysis. What if the study center does not have an up-to-date laboratory infrastructure with qualified and experienced instructors? How can distance learning provide the practical skills, instructional materials, and easy access to mentors and tutors? How can they deal with non-traditional learners with learning styles that are not compatible with the opportunities available to them, or who cannot complete experiments in the limited duration of practical contact session at a regional study centre? All these factors contribute to loss of motivation, limit students’ understanding of fundamental concepts and theories, and reduce learning from the hands-on experimentation.

This clearly indicates that distance learning students require ‘additional innovative learning’ support to enhance, enrich, or improve laboratory courses. A viable solution is interactive multimedia experimental simulation, a technology with the potential to revolutionize the way we work, learn and communicate with distance learners to meet their laboratory requirement.

Multimedia Simulation has advantages over hands-on laboratory activity. It allows students to practice more complicated and hazardous experiments, work at their own pace, obtain reproducible results more rapidly, and foster a deeper understanding of the experiments due to integration of various media. True interactivity implies that the learning process is, in some degree, modified by the actions of the learners, thus changing the roles of both the learner and the teacher. Furthermore, it helps in developing knowledge and skills required for real world activities.

To proffer all the potential advantages of interactive multimedia simulation and provide healthy laboratory learning environment, ‘Wien Bridge Oscillator’ experiment from Basic Electronics Course were simulated using Flash MX 2004 as a prototype. This not only simulates media rich lab environment required to perform ‘Wien Bridge Oscillator’ but also engages the learner to,

• Perform lab activity on the computer before it was carried out in lab and real world environments;

• Practice in a low-risk environment, anytime, anywhere; without affecting real data/equipment,

• Observe the circuit behavior by manipulating variables such as supply voltage, components values, etc. and relate with theoretical concepts;

• Build self-confidence and enable learners to self-assess whether they are ready to perform lab activity effectively in real environment.

It was intended that the students use this lab simulation as part of their laboratory exercises to enhance their comprehension of lab procedure. It does not aim to replace laboratory work with simulated experiments, rather it provides students with a better idea of what to expect on entering into the laboratory. Researchers expect that this kind of pre-laboratory exposure will enable students to use valuable laboratory time efficiently and discuss the results of their work.

Research Objectives

This research project involved designing, developing and piloting interactive computer simulation. It implements instructional design principles to enhance learning via interactive multimedia in context with Electronics Lab activities.  Hence objectives of this research are to,

1. Develop interactive simulation environment to perform Wien Bridge Oscillator experiments using state of art computer technology

2. Design instructional patterns for development of Electronics experiments using distance education pedagogy

3. Test effectiveness of simulated environment on student comprehension using randomized self test based on theory and lab knowledge with immediate feedback.

4. Evaluate the instructional pattern of simulated experiment with total quality parameter feedback sheet supplied to students and experts

Review of Related Literature

A simulation model represents a real and/or imaginary system in action. The purpose of the simulation is to enable users to explore interactions between the elements, observe system operation over the time and ask what if questions about the effects of changes to any of the system elements or attributes (Banks, 1998, 1999; Sauve, Renaud, & Kaufman, 2005). In learning, developing and testing theories, more emphasis is given on the interactive simulation to achieve intended and desired learning outcomes.

The behavioural theories of learning offered major advances in simulation design by modelling student learning on that of a simple organism whose behavior will be modified in accordance with externally supplied feedback. This approach implied that desired learning outcomes could be achieved through assessment of a student's entry level skills, identification of differences between entry and target skill levels, and provision of structured practice with feedback until the predefined learning outcomes were achieved (Fosnot, 1984).

Further advances in understanding instructional simulation come from cognitive theories of learning. Cognitivists argue that each student should be considered as possessing unique ways of processing information from the environment and subsequently modifying their behavior. This approach de-emphasises the importance, and even validity, of strictly defining learning outcomes and focuses instructional design on providing an environment which supports, rather than directs, individual learning.

Simulations provide a learning environment which has the ability to ‘learn by doing’. This hands-on, experiential type of learning is one of the key features of constructivist learning theory. Constructivism is one which illustrates the concept well. "Learning is the construction of knowledge not the absorption of it ... The learner must be active and must be relating new knowledge to existing knowledge" (Burton, 1988). While being learner centred, constructivism does not imply that instructional staffs are unnecessary. Evidence that "learners benefit from guidance in their perception of the learning task" is well documented (Fleming and Levie, 1978). Indeed, without proper guidance the vagaries of an individual's perception could lead to unintended and undesired learning outcomes.

The researcher also reviewed some of these examples:. Hall (2000) studied the use of computer simulations (Electronics Workbench) to perform laboratory experiments for electronics engineering technology course and compared results with using actual components in the hands-on laboratories to perform the same experiments. The quantitative research showed no significant differences in the performance of control and experimental groups. However, he found from the recommendations garnered in qualitative research that incorporating elements of both hardware and simulation into the laboratory pedagogy should help improve students’ experience regardless of the environment in which the laboratory is conducted. Campbell, Bourne, Mosterman, & Brodersen (2002) conducted an experimental study as part of an on-campus beginning circuit’s course. The results indicated that student performance was equivalent to or better than the performance of students using traditional physical labs.

Like Hall and Campbell, this researcher is not directly comparing real laboratory work with simulations alone, or with simulations that are readymade and commercially available. This researcher will test the effectiveness of self developed interactive simulations based on instructional pedagogy which suits the targeted learning goals.

Methodology

Faculty and students of the aforesaid programme were asked to participate in the evaluation of the developed simulation lab activity using a rating instrument and interviews. The research described in this paper comprises a quasi-experimental research methodology.  Quasi-experimental is particularly suited to situations where it is impossible to have a control over subject characteristics like the level of knowledge, grasping capacity, background etc. and where it is necessary to select subjects for the different conditions from previously existing groups. According to Wiersma William (1991), ‘Quasi experiment research involves the use of intact groups of subjects in an experiment, rather than assigning subjects at random to experiment’. In this research, the intact group is fourth semester students (learners) of the B.Tech Electronics programme of YCMOU. Here, independent variable is product ‘practical simulation on wien bridge oscillator’ and performance level of learner is the dependent variable. Researcher had taken a sample of learners and measured their performance level by administering a randomized pretest, referred as pre-experimental evaluation. Then a group of individuals was exposed to a product (media stimulus) for a period of time i.e. the influence of independent variable and finally randomized posttest was conducted to again measure the performance level to see whether there has been any change in the score.

Further, faculty and students were asked to evaluate the quality of the developed simulation using an established rating instrument and provide feedback for improvement and effective dissemination of lab experience.

 

Design and Development of Prototype

Steps involved in development of Prototype
 

Figure 1: Design Process of Electronics practical Lab Simulation

After performing the need analysis for selection of topic, the learners’ profile was analysed to match the content illustrations and activities involved in the lab simulation to the target age group, interests, culture, background, environment of ESEP students.

Learners need to become involved and motivated by the materials and to take ownership of the skills and knowledge that they acquire (Derek Rowntree, 1993); for that, presentation of content of Wien bridge oscillator was based on distance education pedagogy (through Self Instructional Material). The organization of content is shown in the following figure 2.

Fig 2: Content Organization

Course Description

The content contained within the simulation was intended to provide students with a theoretical knowledge base which would enhance their ability to apply concepts in a variety of situations. First outline like the course title, sequence of content, prerequisites and relation to the rest of the course content, access flexibility etc. incorporated; since the learner may access the course content in non linear fashion.

Content Outline

Content outline showed a list of specific main topics and sub-topics, presented under the module headings. For instance, in main topic theory, several small topics were made and in each sub topic minimum content was placed which made the learners learning more effective. In theory topics, prerequisites are clearly mentioned. For enhancing comprehension of major concepts only static diagram with plain text explanation is not sufficient, researcher had given focus on animated diagram/graphics with explanation. At the end of this topic, summary is given to review main points covered to reinforce the content.

The Learning Environment

The learning environment determines how learners would to learn the content. Due consideration is given to the overall approach; focus is on the learning activities or the process rather than the content. For instance, for performing the Wien bridge oscillator in simulation environment, first the learner must enter various component values, required power supply voltage within specified range of voltage. Then learners could observe response of the oscillator circuit that is output waveform on simulated Oscilloscope. Hence learner could measure the amplitude and frequency of the output waveform manually. This would provide complete hands on, how to perform the same experiment in the real environment. The user could vary the components values to vary gain and frequency along with the power supply voltages (+Vcc and -Vcc) to explore both the ideal and real characteristics of the circuit.

Incorporation of such learner/computer interaction has undoubtedly enhanced the way electronics was taught or learned. In fact, circuit simulation through state of art computer technology offers following advantages.

• Learner's role turns from passive to active, which improves learner attention.

• Learner can visualize all circuit waveforms at once and relate cause and effect, which helps in the acquisition of concepts.

• Amplitude or frequency of output waveform can be readily measured without the need for actually inserting measurement instruments

• Learner can easily change a parameter value and investigate its effect on the circuit's behavior. 

Study Tips

List of reference books and web links were provided to access more information through Internet. The data sheet of IC 741 in PDF format was given to study its electrical characteristics and specification.

Home Assignment

To motivate the further reading and enhance comprehension, descriptive type of items based on the content covered were given as a home assignment.

Self Test

Self test was designed to get immediate, most realistic and effective feedback about the course content learned. The novel feature of this self test was ‘randomization’. Every time, questions were randomly pulled from large items of question bank, hence next question presented to learner was unknown to him/her. Self test consists of three types of items like ‘Multiple Choice Questions (MCQ)’, ‘fill in the blanks’ and ‘true or false’. Learner gets immediate feedback on his or her performance after giving. At the end of self test, learner’s performance is reported in the form of total correct answers, total wrong answers and total percentage.

At the conclusion of the activity, the learner is presented with a unique summary of what should have been learnt in the activity.

Media Selection

A good teacher seeks as many ways as possible to present information and ideas to learners and to stimulate their thinking for enhancing their learning process. The most common buzzword used in education is Multimedia, which is the integration of text, audio, video, graphics and animation into a single medium. Integration of different media multiplies the impact of a message. According to the research reports by Mayer and McCarthy (1995) and Walton (1993) 'multimedia has gained acceptance with many benefits derived from its use. Learning gains are 56% greater, consistency of learning is 50-60% better and content retention is 25-50% higher'. Instructional multimedia focuses on what the learner is expected to do upon complexion of the instruction.

Appropriate media selection is important to match the learning objectives and to synchronize the design and learning from it.

For example, Wien bridge oscillator circuit behavior for various components values could be shown through animation and also through a video programme. However, here multimedia is used as it offers interactivity. Learners could actually observe and feel sustain or overdamped or underdamped oscillations which were generated as per the component values provided by them; like an actual experiment. Similarly, to ‘Built oscillator circuit on breadboard’, a step by step activity is animated using different media text/photographs/images to make instruction effective.

Authoring Tool

Due attention is given in selecting the authoring tool on software features such as usability, animations, smoothness, integration, delivery, user friendliness, clientele and cost effectiveness. Each authoring tool has its own features, merits and limitations.

For creating animations Macromedia Flash is the industry standard. It is an authoring tool that allows to create anything from a simple animation to a complex interactive web application. It allows making Flash applications media rich by adding pictures/images, graphics, sound, and video. A file created in Flash is called a movie. A movie in Flash occupies very less file size, and hence is more popular for putting it on the Web. Flash MX 2004 is an excellent development environment for making interactive applications, enhancing productivity and ease-of-uses. It's possible to create graphical user interfaces for stand-alone and self learning (user friendly) product with increased interactivity by the use of ActionScript. This is a programming language build into Flash MX.

Interface Design and Layout

The next step was to decide about interface design and layout. Screen design serves as the internal cognitive structure that prepares the stage for learning, orienting the learning to the objectives and stimulating recall of previously learned information (Taylor, 1992).  It plays the same role as "gaining attention" in Gagne's events of instruction model. Well designed screens should allow for maximum learning from the materials while providing the learner with appropriate control of the learning process (Mlheim & Lavix, 1992). Good screen designs are expected to fulfill a number of requirements: 1) focus learners' attention, 2) develop and maintain interest, 3) promote processing, 4) promote engagement between the learner and content, 5) help learners find and organize information, and 6) facilitate lesson navigation (Grabinger, 1993; Hafinafin & Hooper, 1989; Mukhedee & Edmonds, 1993).

A screen design template was developed after deciding the location of status and progress information, navigational buttons, content display control buttons, and illustrations. The graphic devices such as shading, lines, and boxes were used to separate one area from another.

Navigational item location was consistent throughout a program so a learner does not have to search for the buttons (Hannafin, 1984; Milheim. & Lavix, 1992). Kensworthy (1993) stated that keeping the keys in the same locations throughout a program helps to build confidence in the learner. Hence, after finalizing text font and color scheme, same screen template was used consistently.

Visual: The decision about the graphics attributes like color, texture, pattern and animation is important for the effective communication through graphic presentations and the richness of developed products. Information presented in text is often better recalled and retained when supplemented with pictures (Hooper & Hannafin, 1988).

Animation: A chief element of creating practical simulation environment of this product is animation. Animation is designed as a simulation of movement created by displaying a series of pictures or frames. It is a visual illusion. It builds dynamism, energy and motion to inanimate objects. It also adds the dimension of time to graphics. In this product, using key frames and tweening, the various circuit operation steps and their waveforms, important concepts and key points (text/ graphics) etc. of Wien bridge oscillator are animated to both for the explanation of dynamic processes and for heightening the impact of presentation.

Interactivity: It is nothing but the interplay between different elements of an environment, also referred as navigation. The navigation actually enables the learner to navigate from one screen to any other screen. Some of the important navigation buttons used: start, end, next, previous/back, Main menu, experiment, update diagram etc. In the layout, the placement of the buttons and/or hyperlinks was also specified to jump to sections of interest in the material. Laurillard (1987) suggests that learners should be given more control over the content, access to the content, and interaction with the multimedia content. One way multimedia can give control to the learner by providing the ability to navigate through programs at the learner's own pace and ability level (Sponder & Hilgenfeld, 1994).

Actual Development of Prototype

Based on screen design, lab simulation was developed using Flash MX 2004. Each element of multimedia- text, visuals, animation and navigation was carefully embedded in the screen so that the learner understands the content being presented and should able to work through it faster than expected.  All learning activities were designed to boost the confidence in the learner's abilities and provide apparent feeling of performing Wien bridge oscillator experiment in reality.

Delivery Option for the developed lab simulation

Web compatible technologies and the state of art of compression techniques were used to keep small file size. It allows developed practical simulation of Wien bridge oscillator to be delivered for self learning in two different modes - World Wide Web delivery and stand-alone CD-ROM.

However, in today’s setup, researcher has not recommended web-based delivery of product because of the poor bandwidth of internet.

The CD-ROM drive has become a standard component of computers these days, and therefore it is one of the best options available.

Pilot Testing

Pilot study was conducted on a team of 7 members. The team consists of 4 experts and 3 students. Among the 4 experts, there were two subject experts to examine the content validity, one education expert to examine instructional pedagogy and one technology expert to examine interactivity, user friendliness and ease of use. The comments/suggestions of four students from Diploma in Electronics Engineering who had already performed this experiment using traditional laboratory method, was helpful to test the usefulness of this developed practical simulation while performing the same experiment in the laboratory.

On reviewing the feedback of above team, the relevant suggestions were considered and necessary changes were made in the field tryout of product.

Features of the Developed multimedia Lab Simulation

• Allows learners to navigate freely through the simulated exercises and enables them to pause and play at any time.

• Provides easy and click access to input and output devices, making it efficient to run simulations and conduct “What if …” investigations.

• Easy to use lab interface modeled on common lab procedure

• Allows repeating of lab activities for ‘n’ number of time and enables self-learning anywhere anytime.

• Provides learner with a better idea of what to expect on entering the laboratory and thus make efficient use of valuable laboratory time.

• Can be used as supporting or supplementary learning material for hands-on experimentation in basic electronics course, for both conventional and distance education learner

• Associated with randomized self test and immediate feedback mechanism

• Reports learner performance in the form of total score, total wrong and total correct answers to encourage them for the use of the lab simulation.

• Web Compatible and reduced file size

Participants

The sample for this study included 34 students enrolled in an electronics course offered at 4^th semester in B.Tech Electronics Engineering programme of YCM Open University. A course in basic electronics was a prerequisite for enrollment in this course. All over Maharashtra State, about 30 counselors offer academic support to total 300 learners enrolled at 30 different study centers. This represents 11.33% sample selection of total population of fourth semester. Following study centres were selected for evaluating the effectiveness and quality of the final product.

• Tee Tech Institute, Nashik

• Ahmed Abdula Garib Polytechnic, Mumbra

• Srujan Institute, Mumbai

• NDMVP College of Engineering, Nashik

• K K Wagh College of Engineering, Nashik

Other than students, total 15 faculty/experts/Counselors from the above study centres were selected for the investigation of the product.

Treatment

Evaluators were given a copy of developed lab simulation on CD (cross-platform for Windows operating systems) with both written and oral instructions, and an evaluation form to determine its effectiveness and impact on learning.

Instruments

Two separate questionnaires were specially designed and used by the researcher to collect faculty's and students’ individual assessments of the quality of the product and its effectiveness.

Table 1

Format of Questionnaire

Faculty’s Questionnaire:

The questionnaire for faculty/Counselor/expert consisted of total 26 questions / statements. Out of 26 items, on 14 items faculty were asked to assess quality parameters of the developed product in the following areas using a four point rating scale ranging from low to high and to provide a rationale for their score.

• Content

• Instructional Technology

• Language

• Multimedia and Technical quality

Whereas the remaining 12 items were open ended, asking general opinion about the product. These items were used to provide faculty with an opportunity to suggest modifications for improvement.

Learners’ Questionnaire:

Two separate questionnaires were designed to evaluate ‘Content Knowledge’ and ‘Total Quality’ of the product. The content knowledge was evaluated using pre test and post test. Both pre test and post test were randomized in nature and consisted of total 20 items related to theory and performing lab activity. Bloom's taxonomy (1956) was used as a guide to develop a blueprint for the pre test and post test.

To evaluate the total quality of the product, questionnaire of total 36 items was used. Out of 36 items, 8 items were used to collect the data regarding general background information of learners, 2 items ensured the media exposure and its use. Whereas remaining 26 statements were used to collect the feedback about the practical simulation of Wien bridge oscillator, each of which was followed by four answer choices indicating degree or intensity. All these 26 statements were rated by learner after use of the product. To evaluate the effectiveness of product, rating scale was used so as to enable the respondents to express themselves more precisely.

Data Analysis

A. Learners’ Response

Background Information: A total of 34 subjects participated in this study. Results of the questionnaire revealed that for B.Tech in Electronics Engineering Programme, 85% subjects were within a range of 15 to 25 years and maximum enrolled subjects for this programme were male (97%). The percentage of urban (52.9%) and rural (47.1%) showed nearly equal distribution of sample respondents. The questionnaire also revealed that maximum enrolled learners were SSC pass (58.8%), followed by HSC (29.4%), diploma (2.94%) and then ITI (8.82%) qualification. The maximum (71.94%) subjects were unemployed, learned this course full time or learned along with other education. Remaining was employed (17.65%) and self employed (2.94%), was doing this programme for self satisfaction or to acquire the latest knowledge.

From the questionnaire, it was further revealed that respondents had computer access at study centre (55.88%), home (20.59%), and (11.76%) at work place and /or at cyber cafe. Respondents were well acquainted with use of internet (73%) for performing various activities of home work, college and projects. 14.71% respondents were using CD ROMs for learning the subject content while 8.82% were subscriber to a various learning web sites.

Content Based Questions: The general awareness level of learners about the theory content and practical in-lab knowledge was collected through 20 pre test questions. It contained 17 multiple choice questions, 2 fill in the blank questions and one true or false type of question. Each question of pre test was given 1 mark, totaling it to 20 marks. Same pre test was administered as a posttest to test enhancement in understanding of content and performance level after exploring lab simulation. Both pre test and post test are randomized in nature and embedded in the product but for record keeping these tests were carried out in written form.

Questionwise Response of Respondents

The following figure 3 shows the number of respondents answered each question correctly out of 34 respondents.

Figure 3: Questionwise Response.

For 20 content based questions, the range of correctly answered respondents varied from minimum 5.88% to the maximum 91.18% for pre test and from minimum 11.76% to the maximum 94.12% for post test. The increased height of bar indicates that the rise in knowledge level after utilization of the product.

The above analysis indicates that the use of multimedia increased the involvement of learner. A active participation of learner helps to better understand content. The most positive responses for more than 50% questions after exposure of the product itself indicated the effectiveness of the product for better understanding. However, some respondents had shown unfavorable response, due to lack of curiosity, readiness to learn through other mode, their background, learning style etc. They required more practice or efforts to achieve command over the content.

It also indicated that the respondents are more likely to use such product to enhance the end examination performance as performance score is increased in the final post test. They also felt that the information given would be useful in understanding the content of text book as all questions in pretest and post test were content based.
 

Statistical Analysis of Pretest and Post Test Score

Table  2 summarizes the important statistical information regarding the pretest and post test data of 34 respondents.

Table 2

Statistical Analysis of Pretest and Post Test Score