e-mail: mckay@cmsu1.cmsu.edu

INTRODUCTION
PROCEDURE
METHOD
RESULTS
CONCLUSION
REFERENCES

At Central Missouri State University, we recognized the changing student demographics and increasing non-traditional composition in our courses. It was necessary to accommodate that population within the standards and limitations of the department's resources. In the chemistry department, we have focused on developing an electronic chemistry community to better serve our students. Using WebCT® or Blackboard® as the platform, we have enhanced our general chemistry laboratory experience. Video segments pertaining to techniques, calculations, and procedures from standard general chemistry laboratories, such as a Beer's Law and acid base titrations, were filmed, converted to movie files, edited, and placed on the department web server. On-line pre-laboratory quizzes in the electronic medium were used to gauge the students' basic understanding of the laboratory procedure and safety issues. Admittance to the laboratory was restricted to students that demonstrated appropriate lab preparation by passing a pre-laboratory quiz. The video and on-line quizzes were available on the Internet so that these materials could be accessed from the students' homes and at their convenience.

INTRODUCTION

There has been a significant change in the profile of the typical Central Missouri State University (CMSU) student. A larger number of students define themselves as non-traditional or as spending more time away from the campus addressing family or work concerns. Absence from the campus creates increasingly complex scheduling issues for the students and instructors. It has become increasingly difficult for the student to schedule not only on campus activities but also time to prepare for classes and laboratories. Web based tools [1-22] are an essential and necessary part of course delivery for the modern student.

A pilot program was instituted at CMSU for the purpose of better preparing both traditional and nontraditional general chemistry students for laboratory activities. Multimedia materials were developed and delivered using technology such as WebCT® online quiz and grading tools, Internet streaming video, and Macintosh's i-Movie®. The pilot project included two laboratories, a Beer's law laboratory and an acid/base titration laboratory, for the first semester general chemistry course.

Videotaping of laboratory exercises, laboratory techniques, and subsequent assessment via prelab quizzes is not novel [22-26]; however the thrust of these activities was to improve the student’s experience in lab using a combination of new technologies that would especially help non-traditional students. The incorporation of these technologies would provide a more manageable and efficient vehicle for departments that do not have an abundance of teaching assistants to better prepare students. This technology would greatly reduce the personnel hours needed for grading because the quizzes are graded and entered into spreadsheets automatically. WebCT® or BlackBoard® on-line course management programs allowed for convenient delivery of quizzes, automatic grading, quiz feedback, and instantaneous grade updates. During the course of this study the university replaced the WebCT® program with the BlackBoard® course management program. Both of these tools were adequate and instrumental in facilitating the student’s lab preparation expectations. Internet delivery of quizzes and video provided a great deal of flexibility and convenience for students, especially non-traditional students.

PROCEDURE

Ten to twenty minute segments of video were shot for each of the two laboratories in this study (Beer's Law part I , part II, part III, part IV; Acid/Base Titrations part I, part II). The video segments typically addressed technique, equipment, terminology, and pertinent calculations. The video was not intended to replace the traditional pre-laboratory lectures. Instead, the video segments and subsequent pre-laboratory assessments in the form of on-line quizzes were intended to reinforce key concepts, calculations, and techniques.

Specific goals (Table 1) and initial and final (Tables 2-5) pre-laboratory surveys (this research has been cleared by the Human Subjects Committee at CMSU) were generated with the assistance of the FLAG website [27]. One intended goal of this study was to increase the students' preparedness before entering the laboratory. Student's comfort level increases with familiarity of techniques, equipment, and calculations germane to a specific laboratory. The familiarity was assessed with an on-line quiz before performing the experiment. The survey was used to measure the effectiveness of the pre-laboratory video/quiz activities in meeting the goals and objectives of the experiments. Mitigating variables, such as initial background for the course and previous exposure to resources, were taken into account during the data analysis.

METHOD

Video segments were shot using a Panasonic color video camera wv-3240 Proline® in-house by the chemistry faculty. The video segments typically showed a faculty member actually demonstrating a technique, procedure, or a calculation. The video was downloaded to Macintosh's i-Movie® and converted to .avi files after editing. The videos were then compressed using QuickTime Pro®. The pilot videos included acid base titrations, Beer's Law experiment, and techniques such as titration, transfer of liquids, use of a spectrophotometer, and weighing. The videos also contained pertinent calculations and background for the specific experiments.

General chemistry I students were invited to complete two surveys for the laboratory portion of the course. The data was collected from three sections of general chemistry laboratories. An initial pre-laboratory survey was given near the beginning of the course and a final pre-laboratory survey was given near the end of the course. Two labs were specifically chosen to incorporate web-based components. The Beer's Law and Acid/Base Titration activities were chosen because they are well known and established general chemistry experiments and involved several important techniques common to many chemistry laboratories. The surveys were completely anonymous and voluntary. The students were asked to provide their own identifier known only to them so that the initial and final surveys could be correlated at the conclusion of the course.

The laboratory quizzes were typically available through WebCT® or Blackboard® one week prior to performing the actual experiment. The video segments could be accessed through the University's streaming server and viewed in either a 56k or T1 version, differing only in resolution. If the streaming server was experiencing difficulties, the videos were made available on local machines or were available in the on-line course management programs. There were no significant problems encountered by the students when the videos were served via the course management programs. On occasion remote sites could be interrupted, but the students could log back on and retake the quiz.

The quizzes were accessible 24 hours a day over the Internet by way of the on-line course management programs (WebCT® or BlackBoard®). Students were allowed to take the quizzes an unlimited number of times. A ten minute delay was required between subsequent attempts. Thirty minutes were provided to complete the quiz. If the quiz was not submitted before the time expired, the quiz could not be submitted for a grade. A minimum score of 80% was required to receive credit for the quiz. Entrance into the laboratory was prohibited until the student received a minimum score of 80% on the pre-laboratory quiz. A computer lab was available at the beginning of the lab period for those students that had not earned a passing score.

The purpose of the quizzes primarily was to be sure the student carefully read and was prepared to perform the laboratory. The quizzes typically contained key concepts, fundamental principles or arithmetic questions pertaining to the day’s laboratory for example:

		According to Beer's Law, on what does the observed absorbance depend?
		List the type of electromagnetic radiation from the highest energy to the lowest energy. x-rays, microwaves, ultraviolet, visible, radio
		A sample containing 10 drops of blue food coloring in 1.00 L is diluted using the following procedure: (1) 25.00 mL of the original solution is transferred by pipet and added to 25.00 mL of water; (2) from this solution, 25.00 mL is transferred by pipet and added to 25.00 mL of water. Determine the concentration of the diluted solution.
		A 15.00 mL sample of hydrochloric acid was titrated with a 0.08524 M standard sodium hydroxide solution. A total of 35.34 mL of the titrant was required to reach the endpoint of the titration. Determine the concentration of the acid solution.
		In an acidic solution, the indicator phenolphthalein is what color?

RESULTS

Three sections of General Chemistry I students were given intial pre-laboratory and final pre-laboratory surveys. The number of student responses is provided in parenthesis immediately following text in each table. Standard deviations are provided parenthetically immediately following the Likert value in each table. The surveys were used to measure the effectiveness of the pre-laboratory video/quiz activities in meeting the goals and objectives of the Acid/Base Titration and Beer's Law experiments. Analysis of the results from tables 2-5 were broken down by majors or disciplines into 5 categories (health related fields, geology, biology, chemistry, and "other") to see if the student's perception of the pre-lab exercises was in anyway dependent on the major of the student. The survey questions, based on a Likert scale, were rated as strongly agree, agree, neutral, disagree or strongly disagree with numerical values of 5,4,3,2,1, respectively. Several questions appeared in both the initial pre-laboratory and final pre-laboratory survey, including questions 2-8 from the initial pre-lab survey. These questions were compared explicitly in tables 2-3 and have been combined in table 4.

The initial pre-laboratory questions (table 2, questions 2-6) focused on providing information to the "confidence" or background of the students in chemistry and computer use. Students were initially neutral in confidence and comfort levels with chemistry equipment and techniques (table 2, questions 2-6). However, their confidence and comfort levels did increase during the course of the study (table 3, questions 1-5). Analysis revealed three questions (table2, questions 2-4; table 3, questions 1-3) out of this group that yielded statistically significant different responses (table 4). The relatively small increase in confidence and comfort overall was most likely due to the fact that most college science majors have had significant science in high school and feel they are fairly well prepared before matriculation. This was evident even more so in the significantly higher average responses to questions 1-6 from table 2 for chemistry majors.

Questions that pertained to computers (table 2, questions 7,8) were duplicated in the final pre-laboratory survey (table 3, questions 6,7). These two questions addressed the student’s “comfort with using on-line resources and “comfort with the use of computers. There was no significant difference between the initial and final survey average response to these questions.

Most students had little experience with pre-lab quizzes (table 2, question 9). Initially students did not feel that pre-laboratory quizzes would help them prepare more effectively for laboratory (table 2, question 10). However, there was a statistically significant increase (t = 4.00, p < 0.05, d.f. = 75, table 4) in perception by the students that the pre-laboratory quizzes did help them prepare for lab more effectively in the final pre-laboratory survey (table 3, question 8).

However, the main focus of this work was to determine whether the students perceive these pre-laboratory activities to be relevant within the context of the delivery method. The final pre-laboratory survey questions (table 3, questions 10-14) addressed these issues specifically. The students generally agreed that they were more motivated to prepare for lab (table 3, question 10) and they generally felt better prepared to conduct the laboratory experiment (table 3, question 11). Further, the students perceived a higher level of comfort when using the laboratory equipment, lab techniques, and the lab calculations as a result of the pre-lab activities (table 3, questions 12-14).

Overall data has been combined in table 4 for questions that appeared in both initial pre-laboratory and final pre-laboratory surveys for convenience and to identify statistical significance. The ultimate goal of this work was to find methods to better prepare students for the general chemistry laboratory and facilitate success in the laboratory portion of the course. In table 5 we compare students who completed the course to those who withdrew from the course. The students who did not succeed in the course perceived themselves as not being familiar with equipment, or comfortable with using equipment or confident in their technique or ability to carry out calculations (table 5, questions 2-5). In general, the students perceived themselves as poorly prepared to enter a college chemistry laboratory. The activities may benefit the students who perceived themselves as poorly prepared by giving them more confidence before they enter the laboratory.

CONCLUSION

The pre-laboratory activities were perceived by the students to make them more confident in their technique (t = 2.75, p < 0.05, d.f. = 75) and ability to successfully complete the laboratory. This may provide a welcome relief of stress that can accompany many laboratory environments. Many of these activities require a great deal of time to tape and format the quizzes. However, the students were receptive to the materials and generally perceived them to be beneficial and worthwhile.

We find that the most efficient method to deliver video content was to use the course management programs that many universities have adopted. There was no need for special stream servers or additional hardware to deliver the video and quizzes. Digital video can be quickly edited in Macintosh’s i-Movie® and exported as Quicktime® movies, but be prepared to have at least 20GB available on the hard-drive to make 15-20 minute videos. The video in this work was shot and edited entirely in the department of chemistry at CMSU. However, access to professional media arts personnel is highly desirable and will improve the quality of the product and in the end reduce the amount of time to produce quality video segments.

REFERENCES

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CEJ Vol. 8, No. 1, Contents