Last update at : Wed May 3 10:44:49 1995

Net-Frog: Using the WWW to Learn About Frog Dissection and Anatomy

Net-Frog: Using the WWW to Learn About Frog Dissection and Anatomy

April 28, 1995

Mable B. Kinzie
Associate Professor, Instructional Technology, University of Virginia

Valerie A. Larsen
Graduate Research Assistant, Instructional Technology, University of Virginia

Joseph B. Burch
Computer Systems Engineer, Information Technology & Communications, University of Virginia

Steven M. Boker
Graduate Research Assistant, Center for Developmental & Health Research Methodology, Department of Psychology, University of Virginia


In this paper, we will first describe the instructional purposes and design of the Interactive Frog Dissection. We will discuss the importance of the web's HTML for development and for distribution and use. We will then describe the design of Net-Frog, and the ways that the heavily visited web site (over 62,000 separate visits were logged in its first eight months) is being used. Finally, we will consider how use of Net-Frog has encouraged use of the Internet.

To go to "Net-Frog," click here:


1.0 Introduction

2.0 Purpose of The Interactive Frog Dissection

3.0 The Importance of the WWW for Distribution and Use of Educational Materials

4.0 Design of Net-Frog

5.0 Use of Net-Frog: Quantitative and Qualitative Data

6.0 Evolution of Net-Frog and Educational Use of the Internet


Author Information

1.0 Introduction

The Internet and World-Wide Web (WWW) provide us with the potential to change the nature of learning. We can use it to increase access to effective instructional materials in a variety of media. With this increased access anyone with an Internet connection and a desire to learn can do so. Our success with the WWW version of The Interactive Frog Dissection, Net-Frog, provides us with an indication of some of what is possible.

2.0 Purpose of The Interactive Frog Dissection

Frog dissection in our nation's high schools is widespread. It has been estimated that 75 to 80% of the country's four million high school biology students dissect frogs [1]. Some of these students are refusing to conduct dissections on moral grounds. Animal rights groups have developed student and educator outreach programs encouraging alternatives to dissection. Legislation has been passed in some states (such as California and Florida) protecting the rights of students who do not wish to participate in dissection [1].

In addition, controversy has emerged surrounding environmental issues (specimens are collected in the wild), economic issues (specimens are expensive), and educational issues (students are not well-prepared to learn from dissection). (See [2] for a more complete discussion of these issues.) While some science educators and scholars advocate replacing the traditional dissection lab with the study of live organisms [1,3], others, such as Berman [4], Hoskins [5], and Igelsrud [6,7], express support for dissection. Their support, however, is conditional upon the use of great care and planning in the design of lessons using animal specimens.

Currently available alternatives include books, charts, computer programs, models, filmstrips, slides, transparencies, videotapes, and videodiscs. Many of these, however, can be faulted for their lack of realism and opportunities for student involvement. We initially developed the videodisc-based Interactive Frog Dissection to provide both realistic imagery and opportunities for student practice on frog dissection and anatomical identification. We also hoped the program would serve as both a substitute for laboratory dissection, where necessary, and as a supplement that would better prepare students for the dissection experience [8]. Versions of the program were created for the PC [8, 9] and the Macintosh computer [10].

Our research with these videodisc-based materials suggests that students using them instead of dissecting will perform as well as students who dissect, when tested on knowledge of frog anatomy and on dissection procedures [2, 8, 11]. Further, we found that students who used the materials prior to conducting a dissection performed the subsequent dissection more effectively than students receiving no preparation and more effectively than students viewing a videotape as preparation [2]. Students who dissected after using the materials as preparation also learned more about frog anatomy and dissection procedures than those who dissected without preparation [2].

Despite these positive findings, we experienced difficulties getting the videodisc-based materials into classroom use. While educators were enthusiastic about using them, we ran into problems on two fronts: hardware and software. In order to use the materials, teachers had to have access not only to a computer, but to a videodisc player and video monitor, at the least. If they were to use the PC materials, the difficulties increased because specific video overlay and videodisc controller cards were required, along with a touch screen. Software availability was also an issue. The materials had been developed with internal research funds. Once our initial pressing of several hundred videodiscs had been given away, there were no funds for additional pressings. Being a university school of education, we lacked the mechanisms for bankrolling, marketing and distributing educational software.

3.0 The Importance of the WWW for Distribution and Use of Educational Materials

With the WWW, widespread distribution of instructional multimedia programs, such as The Interactive Frog Dissection, is made possible. In our case, only one version needed to be created with HTML for access from a variety of computer types (PC-compatible, Macintosh, Workstation, etc.). (Previously, development for multiple platforms involved time-consuming porting activity for each platform type, ultimately limiting program access for users of certain types of computers.) Access to the resulting WWW version of the materials, which we call Net-Frog, is no longer restricted to those who have the videodisc containing the multimedia materials on frog dissection. All that is needed is an Internet connection, a web browser, and a QuickTime movie player (the last two have been readily available via the Internet).

As a research university, we are no longer limited by non-existent budgets for multiple platform development, and by our lack of software marketing and distribution functions. We can focus on what we do best: instructional research and development. Barriers for users, such as possession of a videodisc or access to specific hardware components, have been removed. In the first eight months since its Internet release in August, 1994, Net-Frog has been used more each week (an average of 1,943 visits/week) than the videodisc-based program had been used in its previous five years of existence. Note: This is a conservative estimate. For information on how this and other data were determined, see section 5.0.

4.0 Design of Net-Frog

Figure 1: "Net-Frog" Main Menu

Click to go directly to the Net-Frog Main Menu

Net-Frog provides a laboratory dissection experience on-line (sans the smell). Both preserved and pithed specimens are depicted with 60 in-line color images to highlight the visual similarities and differences in the frog anatomy. QuickTime movies (n = 17) are used to demonstrate dissection techniques, and provide information unavailable from still photographs, such as how to hold the skin with forceps when making incisions, or how the lung inflates. Interactive practice involves users in the experience, asking them to identify critical locations for various dissection procedures and to find various internal organs. Feedback is provided, and the user can always review before attempting a practice activity. In this way, Net-Frog goes beyond just providing information, as illustrated in these user comments:

We worked hard to make Net-Frog easy to use, through clear menu design and provision of navigational options. The photographic images and text are automatically presented. Users are allowed to choose whether or not to download the QuickTime movies or to engage in interactive practice activities. Common user responses include comments such as:

Since the release of "Net-Frog", the instructional worth of the materials has been suggested in comments submitted by biologists at other institutions:

5.0 Use of Net-Frog: Quantitative and Qualitative Data

The popularity of Net-Frog is illustrated by server-generated usage data and by user comments. The data reported below is from an eight-month period, from the announcement of Net-Frog on August 4, 1994 until March 31, 1995. (Two weeks of data were lost during October, 1994, resulting in a total of 32 weeks of data.)

5.1 Quantitative Outcomes

The WWW HTTP server access logs were used to extract the raw access data for Net-Frog. Then, a C-language program was written and executed to convert the raw access data into output files readable by SAS and Splus statistical software. The data was qualified in the process, to remove any non-pertinent data or records containing nonexistent path names or file types. In this way, unsuccessful attempts to access Net-Frog were excluded from our analyses. We also elected to remove all server requests from our own machine address, to ensure that we eliminated any records resulting from program servicing efforts.

Next, a program was written in the Splus statistical language to read the qualified data files. Table 1 contains our summary statistics.

Table 1: Net-Frog Summary Statistics, 8/4/94 -- 3/31/95

We elected to take a conservative approach to determining number of unique machine visits. (By unique machines, we refer to the number of machines for which the address string [whether, alpha, numeric or alphanumeric] is unique.) We considered all access requests received from a single machine address in a given day to be one machine visit. We recorded 62,201 such visits within the 8 month period.

We found that a number of the clients making these visits were repeat customers. We recorded 35,355 unique machine addresses served, suggesting an average of 1.8 visits each.

A total of 1,145,719 files and over 48.5 billion bytes were served, resulting in an average of 18.42 files and 780,107 bytes served per machine visit.

HTML files consisted of 26.3% of the files served (HTML files make up 37.9% of the total program), while 71.8% of files served were GIF images (GIF images make up 43.4% of total program files). QuickTime movies were 1.6% of the total files served (these movies make up 6% of the total program files).

One facet of the Net-Frog statistics that warranted further exploration was the number of unique network domains represented in the data. Our HTTP server software (NCSA HTTPD 1.3) attempts to resolve IP addresses into more human-readable domain names by polling a name-server at the time of access. IP addresses not having a corresponding domain name remain unresolved at this point. Only about 75% of our data was resolved to domain name, leaving about 25% unresolved.

We were curious as to whether these unresolved IP addresses could be further identified. To explore this possibility, we compared the unresolved IP addresses with entries obtained from a standard network reference ("" obtained from on April 6, 1995). If a match was found for the network identifier, we extracted its corresponding domain-style identifier and inserted this into the access logs in much the same way that the original server resolution had been accomplished. By this means, we were able to resolve about 95% of the previously unresolved addresses.

This additional data resolution resulted in the identification of 2 additional unique domain networks (previous figures suggested 68 unique domain networks; our resolution procedures resulted in a total of 70 unique domain networks.

Our clients were located primarily in the United States; 75.8% of the requests that could be tracked to a domain were US-related, with 33.6% from U. S. Educational institutions, 25.2% from U. S. Commercial addresses, 8.0% from Network addresses, 4.5% from the U. S. Government, and 2% or less each from the "United States" domain (2.0%), Non-Profit Organizations (1.5%), and the U. S. Military (1.3%).

Globally, requests from the United Kingdom (5.6%), Canada (5.5%), Germany (2.0%), Netherlands (1.7%), Sweden (1.6%), France (1.2%), and Australia (1.1%) were notable. See Table 2 for a summary.

Table 2: Unique Domain Networks Accessing Net-Frog: Major Players

Note: These proportions were computed following the IP address resolution efforts described in the text.

It is interesting to note that the address resolution procedures reported above did not result in substantially altered proportions (as compared to the proportions that had previously been obtained). The most obvious change was in the number of unique clients attributable to addresses in the United States--this figure increased by 2.5%, up from 73.3%. This increase was influenced by the additional resolutions of IP addresses from U. S. Government (1.1%), U. S. Commercial networks (up .8%), and "Network" addresses (up .45%). Slight decreases in foreign access were concomitant and equally small.

5.2 Qualitative Outcomes

Qualitative data on program use and effectiveness was collected through the use of user comment forms in the web materials. By clicking on the comments form and typing, users were able to send us their thoughts about the program, and their suggestions for future development. The User comments we have received complete the picture of success for Net-Frog:

While usage in schools is still limited due to lack of direct Internet connectivity in the classroom, we are finding that Net-Frog is an ideal tool for parents and children to use together, and for anyone at all to use who is interested in learning:

6.0 Evolution of Net-Frog and Educational Use of the Internet

Net-Frog has great potential for evolution. Many users have suggested companion programs, some of which would provide the on-line dissection experience for other organisms. We also feel that Net-Frog is stimulating greater use of the Internet. From user comments we know that parents and educators are introducing the Internet and WWW to schools, teachers, and students as a function of their exposure to Net-Frog. Bioethics researchers and animal-rights activists are publicizing Net-Frog's availability, and teachers are recommending it to one-another in Internet discussion groups. This exposure is also encouraging individuals to consider other possibilities for Internet use:

We hope that these experiences will continue to encourage innovative and effective instructional practice using the Internet as a powerful tool.


Orlans, F. B. (1988a). Debating dissection. The Science Teacher, 55(8), 36-40.

Kinzie, M. B., Strauss, R., & Foss, J. (1993). The Effects of an Interactive Dissection Simulation on the Performance and Achievement of High School Biology Students. Journal of Research in Science Teaching, 30(8), 989-1000.

Orlans, F. B. (1988b). Should students harm or destroy animal life? The American Biology Teacher, 50, 6-12.

Berman, W. (1984). Dissection dissected. The Science Teacher, 51, 42-49.

Hoskins, B. B. (1979). Sensitizing introductory biology students to bioethics issues. The American Biology Teacher, 41, 151-153, 188.

Igelsrud, D. (1986). Frogs. The American Biology Teacher, 48, 435-437.

Igelsrud, D. (1987). Animal rights and welfare. The American Biology Teacher, 49, 252-256.

Strauss, R., & Kinzie, M. B. (1991). Hi-Tech Alternatives to Dissection. American Biology Teacher, 53(3), 154-158.

Strauss, R., & Kinzie, M. B. (1990). Interactive Frog Dissection. In R. Hairston, (Ed.), The Responsible Use of Animals in Biology Classrooms (Monograph IV). Reston, VA: The National Association of Biology Teachers.

Foss, M. J. (1990). A Hypermedia Program of the Frog: A Laboratory Dissection of Rana Pipiens. In R. Hairston, (Ed.), The Responsible Use of Animals in Biology Classrooms (Monograph IV). Reston, VA: The National Association of Biology Teachers.

Strauss, R., & Kinzie, M. B. (1994). Student Achievement and Attitudes in a Pilot Study Comparing an Interactive Videodisc Simulation to Conventional Dissection. American Biology Teacher, 10.

Author Information

Mable Kinzie, Ph.D., is Associate Professor of Instructional Technology at the University of Virginia's Curry School of Education. She teaches, conducts research, and consults on the effective use of interactive technologies for instruction and information provision.

Valerie Larsen is a doctoral student in Instructional Technology at the University of Virginia's Curry School of Education. She is engaged in research and development on effective use of interactive technologies in adult and teacher education. She is editor of Interface, a national newsletter sponsored by IBM which covers topics relating to technology infusion and teacher education.

Joseph Burch is Computer Systems Engineer with the UNIX Systems Group of Information Technology & Communications, University of Virginia. He is an obsessive C and Perl programmer and is actively exploring web technologies, especially statistical techniques.

Steven M. Boker is a Ph.D. Candidate in the Quantitative Area of the Department of Psychology at the University of Virginia where he studies dynamical systems, the perception of time, and neural modeling. He is the author of several commercial software packages and consults on statistics, data management and software interface design.

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