Trends in histology laboratory teaching in United States medical schools

Authors

  • Robert A. Bloodgood,

    Corresponding author
    • Department of Cell Biology, University of Virginia School of Medicine, P.O. Box 800732, Charlottesville, VA 22908
    Search for more papers by this author
    • Dr. Bloodgood is professor of cell biology at the University of Virginia School of Medicine (UVSOM) since 1980, has taught histology to medical students as a faculty member since 1977, and has been course director for the cell and tissue structure course at UVa since 1999. He is cochair of the committee of all first- and second-year course directors at UVSOM and a member of the School of Medicine's Curriculum Committee. His research interests are in the area of cell motility.

    • Fax: 434-982-3912

  • Robert W. Ogilvie

    Search for more papers by this author
    • Dr. Ogilvie is professor of cell biology and anatomy at the Medical University of South Carolina, where he directs the medical histology and embryology course. He has directed medical histology courses in three medical schools since 1965. He is coeditor, with Jiang Gu, dean of Beijing-College of Medicine, of Virtual Microscopy and Virtual Slides in Teaching, Diagnosis and Research (2005). His research activities over 40 years in academia have included microcirculation of teeth, lung/pulmonary tumors, hyperbaric oxygen treatment, therapeutic effects of exercise, and growth factors on improving circulation to the lower limbs in older persons.


Abstract

Owing to competition for faculty time among the three major missions of today's academic medical centers, as well as the rapid development of computer-based instructional technologies, laboratory instruction in medical schools in the United States has been undergoing dramatic change. In order to determine recent trends in histology laboratory instruction at U.S. medical schools, a detailed Web survey was administered to histology course directors, with about two-thirds of schools responding. The survey was designed to identify trends in the number of hours of histology laboratory instruction that each medical student receives, the amount of faculty effort devoted to histology laboratory instruction, and the use of various computer-based technologies (including virtual microscopy and virtual slides) in histology laboratory instruction. Consistent with the long-term trend of declining total laboratory teaching hours in U.S. medical schools, there is an ongoing reduction in the number of hours of faculty-directed histology laboratory instruction that each medical student receives, with a concomitant reduction in hours of faculty time devoted to histology laboratory instruction. In terms of the tools used in the histology laboratory, there has been a dramatic increase in the use of various forms of computer-aided instruction (including virtual slides). The large increase in the number of schools using computer-aided instruction has not been accompanied by an equivalent decrease in the number of schools that utilize microscopes and glass slides. Rather, the clear trend has been toward a blending of the new computer-based instructional technologies with the long-standing use of microscopes and glass slides. Anat Rec (Part B: New Anat) 289B:169–175, 2006. © 2006 Wiley-Liss, Inc.

INTRODUCTION

Laboratory teaching in U.S. medical schools has experienced dramatic changes, from its rise in the 1870s (Milacek,1966) through its peak years in the first half of the 20th century following the release of the Flexner report (Flexner,1910), to its gradual decline during the past half century (Barzansky,1992; Genuth et al.,1992; Hotez,2003). Gartner (2003) documented a steady decline in laboratory hours in all of the anatomical sciences in U.S. medical schools between 1967 and 2001. For example, between the 1960–1961 academic year and the 1985–1986 academic year, total laboratory teaching hours at the Case Western Reserve University School of Medicine declined from just over 1,000 hr to approximately 350 hr (Genuth et al.,1992). Many factors have probably contributed to the decline of laboratory teaching in U.S. medical schools, including the rise of National Institutes of Health-funded research, managed care, changes in medical practice, reductions in total hours allotted to basic science teaching, and developments in computer-aided instruction. Increased emphasis on patient care and grant-funded basic and clinical research has provided competition for limited faculty resources within medical schools. As Ludmerer (1999) put it, “time spent teaching was incompatible with institutional values that gave priority to research.” Especially in the basic sciences, this has led medical schools to develop strategies for teaching medical students that are less faculty-intensive.

Traditionally, one of the major areas of laboratory teaching in the medical curriculum has been histology (also called microanatomy), where the light microscope has been the primary laboratory instructional tool. The rapidly improved sophistication and power of microcomputers has led to the availability of many forms of computer-aided instruction (CAI) in medical education, which is beginning to offer alternatives for how many areas of the medical curriculum can be delivered to medical students. Peculiar to histology and pathology laboratory instruction has been the development of virtual microscopy and virtual slides (Gu and Ogilvie,2005) as a logical extension of other forms of CAI applied to light microscopic imagery (Downing,1991; Mars and McLean,1996; McLean,2000; Bloodgood,2005; Lei et al.,2005; Ogilvie et al.,2005). Virtual slides can be experienced online (http://www.path.uiowa.edu/virtualslidebox/).

Because there is very limited data to document trends in histology laboratory teaching and how new technologies are being utilized, a detailed survey of histology course directors was conducted during February and March of 2005, and the findings of that survey are reported here. Data were sought primarily in two areas: time commitment of faculty and students to the medical school histology laboratory experience, and the choice of tools for use in histology laboratory teaching and learning.

The advent of computers and digitized images has clearly had a major impact on medical education in general, and particularly on those areas of medical education, such as histology, that are image-intensive (Bloodgood,2005). Increasing sophistication of computer technology has led to the development of attempts to replicate the experience of using a microscope in what is called virtual microscopy and the associated image files that are called virtual slides (Gu and Ogilvie,2005). Virtual slides constitute only one of a number of forms of CAI being utilized in histology instruction and carries a very specific meaning. A virtual slide is generated using a motorized microscope stage and 20× or higher objective lens to scan and digitize (as a series of tiles or strips) an entire glass slide one or more times. The separate digitized pieces are stitched into a single image that is then subjected to a compression algorithm. A sophisticated software program serves as a viewer, allowing a computer user to move around the digitized slide in the X-Y direction, to change magnification, and, in some cases, to focus by changing from one scanned Z-level to another. One of the aims of this study was to document how the recent development of virtual slides and other forms of CAI is impacting histology laboratory instruction in U.S. medical schools.

MATERIALS AND METHODS

The survey was administered via the Web using Survey Suite (http://intercom.virginia.edu/cgi-bin/cgiwrap/intercom/SurveySuite/ss_index.pl). The complete survey can be viewed online (http://intercom.virginia.edu/SurveySuite/Surveys/HistologyLaboratoryTeachingSurvey/index2.html).

Working from a list of histology course directors at U.S. and Canadian medical schools supplied by the American Association of Anatomists, an e-mail message was sent to course directors seeking participation in the survey and providing instructions for accessing the survey. The call for participation in the survey was sent by e-mail in February 2005 and almost all the responses included in the analysis presented in this article were received during February and March of 2005. Data from 82 medical schools are presented here (all but 3 are from U.S. medical schools; this represents slightly less than two-thirds of U.S. medical schools). It was specified that data were being sought specifically related to the teaching of medical students. Specific instructions in the e-mail sent to course directors included a specific definition of a virtual slide as a “digital replication of the tissue on a glass slide that includes all of the information at a given magnification that permits the user to view the tissue section at a wide range of magnification very similar to the experience of viewing a tissue section with a microscope.” When the survey refers to “the last time that you gave your histology course,” we presumed that this refers to the 2004–2005 academic year or the fall of 2005. When the survey refers to “the next time your course is to be offered,” we presumed that this refers to sometime during the 2005–2006 academic year.

RESULTS

Survey results received from 82 medical schools (79 being U.S. medical schools) have been organized into two major areas. Data addressing faculty and student participation in histology laboratory instruction are presented in Tables 1–4, whereas data related to the use of various instructional tools in histology laboratory instruction are presented in Tables 5–8.

Table 1. Which of the following best describes the laboratory component of your course?
Assigned independent study14.6%
Scheduled laboratory sessions with lab instructors85.4%
 Required54.3%
 Optional45.7%
Table 2. Faculty/student ratio in lab
10:116.2%
20:132.4%
30:124.3%
40:19.5%
50:18.1%
> 50:19.5%
Table 3. Has the total number of hours that each student participates in scheduled laboratory activities during the last 3 years
Increased4.9%
Decreased31.7%
Stayed About the Same62.2%
Not Applicable1.2%
Table 4. Indicate whether the number of faculty hours devoted to histology laboratory instruction during the past three years
Increased4.9%
Decreased30.5%
Stayed About the Same63.4%
Not Applicable1.0%
Table 5. For the last time that you gave your histology course, check all of the following that were major tools in the teaching of the laboratory component of your course
Student microscopes and glass slides71.0%
Video microscopes36.6%
Virtual Slides24.4%
Computer-based instructional tools other than Virtual Slides65.9%
CDs or DVDs for independent study35.4%
Table 6. Has your use of microscopes and glass slides for laboratory instruction during the past 3 years
Increased4.9%
Decreased24.4%
Stayed About the Same63.4%
Not Applicable7.3%
Table 7. Has your use of all forms of Computer-Aided Instruction for histology laboratory instruction during the past 3 years?
Increased62.2%
Decreased1.2%
Stayed About the Same31.7%
Not Applicable4.9%
Table 8. Indicate your plans for laboratory teaching for the next time your course is to be offered
Use of Real Microscopes65.9%
Use of Real Microscopes Only6.1%
Use of Virtual Slides50.0%
Use of Virtual Slides Only12.2%
Use of CAI (of all types)92.7%
Use of CAI (of all types) Only32.9%

A large majority of medical schools responding to the survey (85.4%) currently give scheduled laboratory sessions staffed with instructors; of those schools with scheduled laboratory sessions, approximately half (54.3%) require laboratory attendance while the rest have optional attendance (Table 1). At those medical schools offering scheduled laboratory instruction, the average number of hours of faculty-assisted laboratory instruction that each medical student received, during the most recent course administration prior to the survey, was 37.4, with a very wide range (1–75 hr). The staffing ratio of the laboratories also varied widely (Table 2). From the survey, 16.2% of respondents indicated a faculty staffing level in the range of 10 students/faculty instructor; 48.6% of respondents indicated a faculty staffing ratio of 20:1 or less; and 72.9% of respondents indicated a laboratory staffing ratio of 30:1 or less. Data were collected on trends in laboratory participation by students and faculty during the 3 years prior to the survey (Tables 3 and 4). While 31.7% of respondents indicated that the total number of hours that each student participated in scheduled laboratory activities had decreased during the past 3 years, 62.2% indicated that it had stayed about the same (Table 3). A similar trend was reported for the total number of faculty hours devoted to histology laboratory instruction during the previous 3 years, with 30.5% of schools indicating a decrease while 63.4% of schools indicated that the amount of faculty input has stayed about the same. Only about 5% of schools indicated a trend of increasing amounts of time devoted to histology laboratory instruction by faculty or medical students (Tables 3 and 4).

When respondents were asked to list all tools that were utilized for histology laboratory instruction during the last course offering, 71.9% indicated that they used student microscopes and glass slides, 65.9% indicated that they used some form of CAI (other than virtual slides), 36.6% used video microscopes, 35.4% used CDs or DVDs for independent study, and 24.4% used virtual slides (Table 5). In terms of trends during the past 3 years, 24.4% of respondents indicated that their use of microscopes and glass slides had declined, while 64.4% indicated that their use had remained approximately the same (Table 6). Less than 5% of respondents indicated any increase in usage of microscopes and glass slides (Table 6). In regard to recent (last 3 years) trends in use of all forms of CAI (including virtual slides), 62.2% of respondents reported an increase, whereas another 31.7% indicated that their usage stayed about the same (Table 7). Only 1.2% of respondents reported a decrease in usage of CAI in histology laboratory teaching (Table 7). Responses to another question on the survey support the observation that trends in the use of CAI in histology laboratory instruction may be accelerating. When asked about plans for histology laboratory teaching in the year after the survey, 92.7% of respondents indicated that they planned to use some form of CAI (including virtual slides), 65.9% indicated that they would use microscopes and glass slides, and 50% indicated that they would utilize virtual slides (Table 8). However, 6.1% of schools indicated that they would be using only microscopes and glass slides in histology laboratory instruction, 12.2% of respondents indicated that they would be using only virtual slides, and 32.9% indicated that they would be using only CAI (of all types; Table 8). Thus, comparison of the data for the year just prior to the survey (Table 5) with predictions about the year following the survey (Table 8) suggested a considerable increase in use of virtual slides (from 25% to 50%) with very little concomitant decline in use of microscopes and glass slides (from 71.0% to 65.9%). The data shown in Table 8 further suggest that we are rapidly approaching a point in time when most medical schools will be utilizing some form of computer-aided instruction in their laboratory teaching of histology.

The survey contained only one open-ended response question, which asked those surveyed to “share with us your philosophy of laboratory learning and teaching.” Not surprisingly, we received a wide range of comments and a range of positions on various issues raised by the other survey questions. Over a dozen respondents pointed out the critical importance (“instructors are the key”) of the faculty-student interaction in the small-group histology laboratory setting. One pointed out “the key feature of successful histology laboratory instruction: qualified faculty instructors working with small groups of students.” While pointing out that the debates over traditional microscopy versus virtual microscopy and faculty-guided laboratory experiences versus self-study are being driven by resource factors (money, faculty time), “students are best served by expert, stimulating teachers who can provide an effective intellectual framework and motivation for students through personal interactions in small group settings.” One writer speculated that the major loss for students (in a transition from microscopes to virtual microscopy) “is the decreased interaction they have with the faculty.” Another respondent pointed out a conundrum: that “students like working independently in the lab at times they choose, but they also like expert help available at their calling.”

A number of respondents emphasized that “active learning,” “active student participation,” or “personal investigation” is more important than the issue of the tools being used for laboratory instruction. In a related vein, it was pointed out that students need to learn to “interpret an entire specimen” and “students learn better and remember more if they have to search for things”. These comments were clearly an indictment of the use of passive, labeled digital images but did not necessarily distinguish between the use of glass slides versus virtual slides. The key, as pointed out by one respondent, is that medical students use “some sort of searching tool.” One writer argued that “virtual slides maintain the 'exploratory' and analytical aspects of traditional microscopy.”

Although the one open-ended question asked about the philosophy of laboratory learning and teaching, many of the responses addressed the nature of the tools being used for histology laboratory teaching and learning. While about twice as many respondents (32 vs. 14) specifically argued for the primary use of microscopes and slides than argued for the use of only virtual slides and other forms of CAI, more respondents reported the use of a mixture of both and some argued specifically that “improved access to multiple types of visual material … will aid learning.”

A distinction was made between the need to use microscopes and glass slides because they were the most effective tools for learning histology and for gaining the inquiry skills associated with searching and analyzing a slide [a skill well described by Cotter (2001) as learning “how to read microscope slides”], as opposed to the need to learn how to use a microscope as a skill that would be needed later in medical school (pathology, hematology, microbiology, clerkships), residency, and medical practice (particularly in the field of pathology). More respondents argued for the former than for the latter. There is clearly much controversy on both of these fronts. In terms of the need to learn the microscope as a tool for later use, one respondent stated: “After much discussion among ourselves and with input from clinical faculty (principally primary healthcare physicians), we (and they) felt that it was important for students to learn to use the microscope. We feel that one to two sessions with the microscope were inadequate for this.” Another respondent to the present survey pointed out that their “pathology faculty complained about poor microscope skills.” There were a few comments arguing that physicians no longer have to make as much direct use of microscopes as they used to.

An interesting variation on the use of instructional technologies was cited by a few respondents; laboratory instruction utilized primarily or solely CAI, but the laboratory testing utilized microscopes and glass slides, perhaps to ensure that students had some minimal working knowledge of the microscope.

It should be noted that a number of respondents emphasized the importance of medical students being exposed to variability in histological samples as a part of their laboratory training. Many of these respondents used this as an argument for the use of microscopes and glass slides. In this regard, there seems to be an error in logic, because, in either case, the amount of variability available to the student depends on how many different glass slides or digitized virtual slides of each tissue or organ type are provided to the students and not the technology by which it is being provided.

DISCUSSION

Widespread use of laboratory instruction in U.S. medical schools began in the 1870s (Milacek,1966), peaked during the first half of the 20th century, and declined during the second half of the 20th century (Barzansky,1992; Genuth et al.,1992; Hotez,2003; Bloodgood,2005). Ludmerer (1999) suggested that this decline, like changes in other aspects of medical education, likely resulted from the post-WWII rise in research-intensive medical schools and the somewhat later advent of managed care, both of which contributed to shifting faculty time away from the educational mission. As Ludmerer (1999) put it, “teaching experienced a decline in the value system of the institution.”

Prior to this study, there has been very little research that addressed trends in histology laboratory teaching. The present survey of histology course directors at U.S. medical schools was designed to collect data on trends in the amount of time students receive histology laboratory instruction, the amount of faculty time devoted to histology laboratory instruction, and the technology being used to deliver histology laboratory instruction.

One goal of this survey-based study was to identify recent trends in the numbers of hours of histology laboratory instruction that each medical student receives. Gartner (2003) performed a thorough survey of lecture and laboratory teaching hours assigned to histology courses in U.S. medical schools from 1967 to 2001 and found a 50% decline in histology laboratory teaching hours over that period (from an average of 89 hr/course in 1967 to 43 hr/course in 2001). Hightower et al. (1999) reported, from a detailed survey of U.S. and Canadian medical school histology courses administered in 1998, that there was an average of 46 hr of histology laboratory instruction received by each medical student. Drake et al. (2002) presented some data on histology instruction from a comprehensive survey of instruction in all the anatomical sciences, but it was not possible to determine the average number of hours of laboratory instruction from the manner in which the data were presented. The current survey found that medical schools had an average of 37.4 hr of faculty-directed scheduled laboratory instruction during the most recent administration of the course, with 32% of responding schools indicating a trend of decreasing hours of laboratory instruction during the previous 3 years. Coupled with the data from Gartner (2003) and Hightower et al. (1999), our survey documents a continuing trend toward decreasing numbers of hours of histology laboratory instruction.

A related goal of this survey-based study was to identify trends in the amount of faculty effort devoted to histology laboratory instruction. Our survey suggests a trend toward a reduced number of faculty hours being devoted to histology small-group laboratory instruction. In light of the observation cited above of a trend toward decreased numbers of hours of histology laboratory instruction, it is not surprising to see a concomitant decline in the number of hours of faculty time devoted to histology laboratory instruction. The interesting issue is the causal relationship. Has a reduction in availability of faculty time (due to pressures for publication and research grant productivity, for instance) led to reductions in laboratory instruction or has the trend toward a reduction in laboratory contact hours (due to independent reasons such as reduction in curricular time devoted to basic sciences teaching) simply released faculty to devote this time to other institutional missions? Our survey data do not shed light on the causal relationship involved.

In terms of the trends in the use of various forms of technology in histology laboratory teaching, our survey sought to address three major issues. One, has there been a dramatic decline in the use of microscopes and glass slides in the histology teaching laboratory? Two, has there been a dramatic increase in the use of various forms of computer-aided instruction? Three, has there been a trend toward increased use of the specific form of CAI referred to as virtual microscopy?

Coupled with the limited literature on this topic, our survey results indicate that there has not been a dramatic decline in the percentage of medical schools utilizing light microscopes and glass slides in some capacity in their histology laboratory instruction, although there is a downward trend. Hightower et al. (1999) found that approximately 90% of courses utilized microscopes (estimate from the histogram in their Fig. 1). An unpublished 2001 follow-up survey by Dr. Hightower (personal communication) found that 91% of medical schools were using microscopes and 85% of respondents felt that microscopes would continue to be used in their courses “for the foreseeable future.” Drake et al. (2002) reported survey data that found that 86% of medical schools utilized microscopes in their histology laboratory teaching. The current study found that, in the most recent course offered, 71% of schools utilized microscopes in histology laboratory teaching and 66% planned to continue doing so during the next administration of the course.

The advent and rapid rise in sophistication of microcomputer technology have opened up new avenues for the presentation of image-intensive information, such as occurs in the histology laboratory (Bloodgood,2005). In particular, the development of virtual microscopy (Gu and Ogilvie,2005) has provided an alternative to the use of the microscope and glass slides in histology laboratory teaching that, its advocates argue, provides an experience similar to the use of the microscope and glass slides. Fred (Dick) Dee, a pathologist at the University of Iowa, is the pioneer in the introduction of the use of virtual slides in medical student education (Dick,2001; Dee and Heidger,2005). His colleague at Iowa, Paul Heidger, was one of the first to introduce this technology into histology laboratory teaching (Harris et al.,2001; Heidger et al.,2002). Our survey results show a major trend toward increased use of computer-aided instruction in the histology laboratory. Over 62% of respondents indicated that their use of all forms of CAI (including virtual slides) had increased during the past 3 years and 92.7% of respondents indicated that they planned to use some form of CAI during the next administration of their course. Considering only virtual slides, there is also evidence for increased usage of this specific computer-based technology in the histology laboratory; while 24.4% of respondents reported using virtual slides during the last administration of their course, 50.0% of respondents reported that they were planning some use of virtual slides during the next administration of their course.

The most important conclusion from this survey study about the use of various technologies in histology laboratory teaching is that most schools are using a mixture of teaching tools in their histology laboratory instruction. Whereas 92.7% of respondents are planning to use some form of CAI during the next administration of their course, only 32.9% indicate that they will be using only CAI. While 50.0% of schools anticipate using virtual slides during the next administration of their course, only 12.2% indicate that they will use only virtual slides. Although 65.9% of schools indicate that they plan to use microscopes during the next administration of their course, only 6.1% report that they plan to use only microscopes. Clearly, the trend is toward embracing a new technology while not discarding the old; this does not mean that incorporation of CAI instruction has not resulted in altering the extent of usage of light microscopes and glass slides in the histology laboratory. While most of our survey data do not speak to this, some of the comments on the one open-ended question in the survey suggest that there is indeed a reduction in the extent of use of microscopes and glass slides at some of these medical schools that are continuing to use them, but in concert with computer-aided instructional materials. The choice of most medical schools to use a mixture of approaches in histology laboratory education is consistent with recent research (Lujan and DiCarlo,2005) showing that first-year medical students prefer multiple learning styles. Indeed, McLean (2000) reported that 86.3% of medical students agreed that “the successful study of histology requires a balance between microscopy and CAI.”

Does the technology used in the histology teaching laboratory make a significant difference in medical student performance in course level testing? Although there has been very little research addressing this question, some recent data suggest that the technology used in the laboratory may not be a very big factor in student performance on course level assessments of histology knowledge. Mars and McLean (1996) performed a small study at the University of Natal Medical School comparing the performance of two groups of medical students on an eye histology unit; students who used only the microscope and glass slides and students who used a CAI program (while still having access to the microscope) showed no statistically significant differences in pre- and posttests. Scoville and Buskirk (2005) performed a carefully controlled study at Eastern Virginia Medical School in which students were divided into four groups that used glass slides for both instruction and assessment; glass slides for study and virtual slides for assessment; virtual slides for study and glass slides for assessment; and Virtual slides for both study and assessment. No significant difference in test performance was noted among these groups. Krippendorf and Lough (2005) switched from all glass slides to all virtual slides and compared the laboratory examination performance of separate classes at the Medical College of Wisconsin using each of these approaches. Again, no significant difference in performance was detected. These studies clearly suggest that the instructional technology utilized in histology laboratory teaching is not a critical factor in student performance on course level assessments. However, this conclusion may well be dependent on the outcomes we choose to measure; we only know that little difference is seen when we test histology content knowledge over the short term. It does not factor in any measure of how long our students retain what they learn or whether performance later in medical school reflects the technology utilized in the histology teaching laboratory (or elsewhere in the curriculum).

In a well-controlled ethnographic study of the impact of introducing a computer-based atlas of images into a traditional microscope-based histology laboratory (Lehman et al.,1999), use of the computer promoted less interaction among students and instructors than did the microscope.

The histology teaching laboratory has the potential to address several goals, including enhancing the histological knowledge of our students; learning inquiry-based skills in the context of learning how to “read” a microscope slide (Cotter,2001); and teaching our students the skills of microscope use. The assessments we do in histology courses may not adequately measure success in attaining all three of these goals. Even though emerging data discussed above (Krippendorf and Lough,2005; Scoville and Buskirk,2005) suggest that various forms of CAI, as well as microscopes and glass slides, can assist medical students in learning histology content, we cannot be sure that the tools we choose to use in the histology laboratory may not affect our success in achieving the other two goals.

The specific reasons for the decline in total laboratory instruction and for changes in faculty involvement and changes in use of instructional tools have not been directly addressed by this study. However, there are anecdotal data as well as hints in the literature that at least some of the schools that have made these changes have done so for reasons other than the anticipation of an improvement in the quality of education received by the students. Examples include reduction in available curricular time (Cotter,2001), teaching laboratory space being converted to other purposes (Dee and Heidger,2005), availability of microscopes (Blake et al.,2003), and competition for faculty time with the research mission.

The widespread adoption of CAI into histology laboratory instruction appears to have been associated with reductions in faculty involvement and associated decreases in the number of hours of faculty-directed laboratory instruction received by medical students. The causal connection is somewhat unclear. Is it that the emergence and adoption (for sound pedagogical reasons) of the new technologies secondarily provided an opportunity for medical schools to shift faculty time away from histology laboratory instruction, release laboratory teaching space for competing institutional purposes, and reduce costs associated with purchasing and maintaining collections of microscopes and glass slides? Or, alternatively, was the shift toward CAI not a pedagogical decision, but rather a direct response to the unequal economic incentives (at the individual faculty, departmental, and institutional level) for use of faculty resources for the three main missions of academic medical centers (teaching, research, and clinical care)? In the latter case, it could be said that the availability of these new technologies may have allowed us to minimize the impact of changing institutional priorities on histology laboratory instruction.

The adoption of virtual microscopy and other forms of CAI should not lead logically to a reduction in the commitment of faculty hours to histology laboratory instruction. If virtual microscopy is designed to imitate faithfully the experience of using a microscope (Gu and Ogilvie,2005), and if trained faculty laboratory instructors were felt to be necessary when histology laboratories were taught utilizing primarily microscopes and glass slides as our teaching tools, why should we feel any less need for involvement of medical educators in the histology laboratory setting when we switch from one technology to the other (especially one that is designed to be imitative of the other)?

Regardless of the driving forces, it is important to ask whether the shift in histology laboratory education from the primary use of microscopes to the use of a mixture of computer-aided instruction (including virtual microscopy) together with microscopes and glass slides (or in a minority of cases a shift to only CAI) results in an overall medical education that is better, worse, or little different? Clearly, we are only beginning to see the advent of carefully controlled research studies addressing this issue. While the initial studies (Mars and McLean,1996; Krippendorf and Lough,2005; Scoville and Buskirk,2005) suggest that the technological tools that are used in the histology laboratory do not represent a significant variable in the performance of medical students on course level tests, the important outcomes occur after the students leave the histology teaching laboratory: success in the rest of the medical curriculum, success in residency, and success in medical practice. Bloodgood (2005) and a number of the course instructors who completed the present survey argue that the intimate involvement of the faculty member is the key to the quality of histology laboratory education and the success of our medical students. As Ludmerer (1999) states: “Teachers are more important than courses. Students should meet the best instructors—and be exposed to them for significant periods of time.”

Acknowledgements

Thanks go to the many histology course directors who completed the surveys that provided the data for this study. Sheila Scoville and Charles Flickinger have kindly read and commented on earlier versions of this paper. Portions of this work were presented in the platform session on “Virtual Microscopy in Teaching Histology” at the 2005 annual meeting of the American Association of Anatomists (Experimental Biology 2005) in San Diego, California.

Ancillary