David Onwood Purdue University at Fort Wayne Indiana 46805
A number of reports1 have appeared which detail successful introductions of "open" laboratories. These have generaIly involved space dedication to a single course, and few time constraints beyond those imposed by building hours and perhaps the semester limits. We had experienced a decreased level of achievement and interest in the %hour laboratory sections of CHM 115-116 (a "quantitative" course for majors and others) and were anxious to respond appropriately. However, the constraints of the multiple uses to which our freshman laboratory rooms are applied, the administrative formulas applied to courses offered in a multi-campus institution, and preparation, supply, and storage limitations, effectively prohibited us from adopting completely "open" laboratories. Within these constraints, however, we have introduced a modified laboratory format which does carry many of the advantages of an "open" laboratory while diminishing the danger of procrastination sometimes associated with completely "open" labs. Each lecture section (-75 students) is assigned to one day a week in a 30-place laboratory, and students schedule themselves in a t times which maximize their own couvenience. Entry to the laboratory is conditional on successful completion of an advance study assignment (ASA) which is part of the manual used for the course.2 We have chosen not to discuss the specifics of laboratory work durine lectures. but rather to emnlov . . a svnchronized " slide-tape medium to compensate for the lack of a conventional lab lecture. This is produced by us and is composed of Kodak Ektagraphic "Write-on" slides together with color slides of salient Darts of the ~ h v s i c a manioulations l involved. The programs are avaiiabie freely during all hours the instructional facilities are open. Students follow a well-defined schedule for their extralaboratory endeavors. ASA's are due two days before the lab day, and are graded and returned the day before the lab day. Inadequacies in student preparation, as demonstrated by ASA performance, are remedied before lab entry is gained. This is controlled by having a successful ASA serve as an admission ticket by stamping i t conspicuously with the legend "ADMIT to LAB" (See figure). Flexibility is maintained by allowing students with occasional time conflicts to attend labs on a different day, with
A Flexible Modification of a Freshman Laboratory
SLIDE
-
PROGRAM The cycle tor students.
another section, and by keeping materials available for one full week after the scheduled use date. We appear to have generated a system within which our students perform well (possibly better than they would in freely "open" laboratories, due to the enforced preparedness resultine from ASA madine). This increased uerformance is reflected in student grades on lab material, and in subjective observations and student responses. We recognize that the improved performance is obtained as much by student time as bv the instructional format: Students average over three hours weekly on lab preparation and reports. Fortunatelv this has not diminished the attractiveness of the courseto our freshmen: the fraction of entering freshmen, who enrolled in CHM 115, increased significantly (chi squared = 9) with the introduction of this laboratory arrangement. Although some of our students complete their practical work in less time than was customary in the past due to the minimization of bottlenecks of the kind resulting from, for example, a student:balance ratio of up t o 15:l; we observe that many prefer to spend more time so as t o be personally satisfied with their observations. An important feature of our approach is that faculty with sections of smaller enrollment (evening classes, off semester, etc.) may choose to maintain the classical threehour format. If they do, they may exercise the option of using available recorded teaching materials as an alternative to a live introductory lecture.
-
'e.g.,
-
-
Cassen T., and Foster, L., J. CHEM. EDUC., 50, 560
(1973).
'Slowinski, E. J., Masterton, W. L., and Wolsey W. C., "Chemical Principles in the Laboratory," 2nd Ed., W. B. Saunders, Philsdelphia, 1973.
VOlumS 53,Number 2. February 1976 / 95
