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Dissection as an Instructional Technique
in Secondary Science: Choice and Alternatives
Alan D. Bowd1 LAKEHEAD UNIVERSITY, CANADA
This article examines the role of dissection in the teaching of
secondary biology and environmental science, within the context of the
development of attitudes toward animals. Retrospective data concerning their
experience in high school with dissection for 191 undergraduate education
students are described, and their reported use of alternatives to invasive
animal study are evaluated in relation to specific educational objectives in
secondary science. It was found that most students were required to perform
dissections, that many but not most experienced negative and stable emotional
reactions, and that teachers employed limited alternatives to dissection in
their classes. The implications of this for secondary science teaching and for
teacher education are discussed.
Dissection for the primary purpose of studying the anatomical
structure of animals has been used for centuries in science education, and
remains an important part of secondary biology and environmental science in
North America and elsewhere (Leib, 1985). Recently the practice of dissection
has come under increasingly critical scrutiny by educators and psychologists
concerned about the sacrifice of animals for teaching purposes (Morton, 1987;
Rowan, 1984; Shapiro, 1987).
Three broad aims are encompassed within secondary science
teaching. These are: (i) an understanding of the process of scientific inquiry,
(ii) the acquisition of skills considered essential for work in science and
technology, (iii) the development of a sensitivity about science and its
influence on, and response to societal issues and values. Laboratory-based
activities, including dissection, have been generally assumed to enhance
"scientific thinking" which is presumed to involve analytic and organizational
abilities, as well as practical investigative skills. However, there is a need
for research to document such assumptions (Hofstein & Lunetta, 1982).
The central affective goal in the secondary science curriculum
is that learning should engender a "reverence for life." This includes teaching
students appropriate care for animals, skills in handling them and returning
them safely to the natural environment, and the maintenance of their health,
comfort and lives (National Science Teachers Association, 1980). The humane
treatment of animals and the development of positive, caring attitudes, is a
recurrent theme in curricular documents across North America. Science teachers
themselves remain responsible for decisions concerning the types of animal study
to employ in the classroom, commensurate with the cognitive and affective
development of students (Boylan & Bowd, 1985).
Critics of dissection have argued that it is contrary to the
aim of engendering a respect for life (Russell, 1980). There is some evidence
that it may create negative emotional reactions in students, distance them
affectively from animals, and teach them to regard animals as expendable tools (Bowd, 1988; Heim, 1981; Kelly, 1986; Russell, 1980). However, there is only
limited data concerning students' emotional reactions to dissection, the degree
of choice permitted them in employing the method, and the actual implementation
of alternatives by teachers. For these reasons, as well as the ethical issues
raised by animal suffering and death, it is important for teachers to be
informed of alternatives to dissection and to employ them appropriately.
Method
Undergraduate education students attending a mandatory course
in educational psychology at an Ontario university took part in the study.
Participation was voluntary, and no available students declined. Of 250
enrolled, 191 in attendance took part (115 females, 76 males). Median age of
participants was 24 years (range 21-46). The majority of students (67%) had
completed grade 12/university entrance level biology or environmental science,
24% had completed these subjects to grade 11 and only 9% had completed them to
less than a grade 11 level.
Participants completed a self-report, anonymous questionnaire
in class. Directions indicated that the questions were designed to explore the
use of dissection and alternatives to it at high school. Age and gender were
requested, and respondents were asked to indicate the level of education
received in secondary biology or environmental science.
Seven items which followed dealt with students' experiences
with dissection. Objective response items addressed whether the student had used
dissection, whether it was compulsory in some or all relevant courses, whether
the individual had chosen not to enroll in a course because dissection was
required, the range of animals used and the employment of alternatives and
supplements in class. Two open-ended items were used to seek information about
the respondents, feelings about performing dissection at the time, and whether
those feelings had altered.
Results
The substantial majority of students surveyed (88.4%) reported
having carried out dissection in high school. Dissection is part of the biology
and environmental studies syllabus at the grade 11 and grade 12/university
entrance levels in Ontario. Students were asked to indicate whether they had
decided not to enroll in a high school science course because it would involve
dissection, and 10.5% indicated this to be so.
Participation in dissection was a requirement for most students
surveyed. Sixty nine percent indicated that it was a compulsory element of their
courses, 6% stated that it was voluntary in some courses in which they had
enrolled, but compulsory in others, and 19% reported that participation had been
voluntary.
The most commonly used species for dissection are invertebrates
and amphibians, although some mammals, largely rodents, are also widely
employed.
Table 1. Reported frequency of
species used in dissection
|
| Type of animal |
Percentage reporting use |
| Worm/other invertebrate |
61.0 |
| Frog/other amphibian |
81.4 |
| Fish |
27.9 |
| Bird |
5.8 |
| Rat/other rodent |
30.2 |
| Other mammals/separated organs |
41.3 |
Participants were asked to recall and describe their emotional
reactions when they first took part in a dissection procedure. Their open-ended
responses were classified as negative (e.g. "I felt disgust"), neutral/positive
(e.g. "I just felt it was a way to teach us," "I was fascinated") or mixed (e.g.
"I was interested and curious, but also felt revulsion, especially because of
the smell of formaldehyde"). The classification of statements into three
categories was in part determined by the data. A significant number of
participants provided responses which were non-evaluative, along with a
combination of positive and negative reports.
Table 2. Emotional Reactions
to Dissection Experience
|
|
Type of reaction |
Percentage |
| Initial |
Current |
| Positive/neutral |
29.7 |
5.2 |
| Negative |
26.7 |
9.9 |
| Mixed |
38.4 |
2.9 |
| None described |
5.2 |
|
| Unchanged from initial reaction |
|
82.0 |
A larger variety of negative responses to dissection was
apparent in comparison with those classified as neutral and positive. Concern
for animal welfare and conservation was expressed by some: "Bullfrogs will
become endangered eventually," "Animals are feeling creatures, not laboratory
tools," "I am a vegetarian and don't believe in killing animals at all." Others
referred to the instructional worth of dissection: "I didn't learn anything
because we were bored and just fooled about," "I didn't like dissection because
it seemed like a waste of time." A large number of negative responses concerned
physical sensations such as odour: "I hated it because of the smell," "Having to
cut animals open disgusted me: the slimey feel of doing it put me off." Most
positive comments focused on interest aroused in biology through a method seen
as practical and involving direct activity.
The current feelings of students when recalling their
involvement were also obtained and classified in the same way. The data reported
in Table 2 indicate that approximately 30% of respondents report experiencing no
form of negative emotional reaction to dissection, and are either positive or
neutral about the procedure. While 27% report negative feelings exclusively, a
further 38% report negative feelings combined with positive, most often that
their curiosity and interest was aroused. Thus, more than half experience
negative feelings, and about one fourth report negative reactions alone. Most
students indicated that their feelings had remained unchanged from the reported
earlier reactions.
Table 3. Experience with
Alternatives to Dissection
|
|
Alternative |
Percentage reporting experience |
| Charts and diagrams |
56.4 |
| Models |
54.1 |
| Human physiological measures |
31.3 |
| Videotapes or films |
19.2 |
| Internal microphotography |
14.5 |
|
Transparent organisms |
14.5 |
|
Computer simulations |
2.3 |
A majority of participants reported experience with some
alternatives or supplements to dissection (see Table 3). About half reported the
use of models, charts or diagrams in the science classroom, usually in addition
to dissection, rather than as a replacement. Human physiological measurement,
such as heart rate and respiration, was used by about one-third of respondents.
However, only relatively small proportions reported experience with more
sophisticated alternatives such as computer simulations, internal
microphotography films, and videotaped demonstrations.
Discussion and Conclusions
There are two methodological limitations to the present study
which imply that caution should be exercised in generalizing from the data
reported. As a retrospective survey, it must be recognized that memory
distortion may bias data. Respondents were asked to recall experiences which
occurred, on the average, six years previously. However, it should be noted that
the response rate to all items was 100%, including open-ended items, suggesting
that participants experienced little difficulty in recalling the information
requested.
Most participants in this study attended high school in the
province of Ontario, with approximately 10% having attended school elsewhere in
Canada. Secondary biology and environmental science curricula in Ontario are
comparable with those in other jurisdictions in Canada and the United States in
regard to aims, objectives and methods. However, caution should be exercised in
generalizing across education systems.
The data suggest that most students are not permitted choice
regarding participation in dissection when it is a scheduled part of their
secondary science program. It is likely that teachers mandate participation
because they have not been sufficiently sensitized to the central aim of the
life sciences at the secondary level, the encouragement of a reverence for life.
It may also be the case that many are unaware of alternatives, or have not been
encouraged to employ them. The British Veterinary Association Animal Welfare
Foundation has observed that "a very large part of school biology need not
involve dissection at all, and teachers should use the many alternatives which
are now available ... since the enforced practice of dissection can be upsetting
to many students" (British Veterinary Association, n.d.).
The data presented here confirm that many students, and not a
small minority, experience negative feelings about dissection, and that these
reactions are long-lasting. It is apparent that negative emotional responses to
dissection have several sources and do not simply reflect an ethical position
favoring the humane treatment of animals. In particular, students may express a
desire not to participate based upon feelings commonly referred to as
"squeamishness," and not because these feelings are accompanied by a logical set
of ethical beliefs. This observation raises an interesting question: Should
students be excused from dissection simply because they do not like it?
Certainly this would not be considered an adequate reason by many educators who
may cite initial negative reactions in other areas (mathematics, for example),
which disappear with mastery. The most compelling reasons for abandoning
dissection at the secondary level are pedagogical as well as ethical. The method
is ineffective in achieving stated objectives, contrary to basic goals in the
teaching of natural science, and easily replaced by superior alternatives.
Teachers need to be made aware of these facts, particularly in
relation to the likelihood that the vast majority of students forced to perform
dissections in high school will not be entering professions where such skills
will be applied. Sharpe (1988) notes that many British educational institutions
have endorsed the Students' charter of rights to violence-free science, a
statement endorsing the right of choice without academic penalty. The present
data tend to support the value of choice in reducing negative emotional outcomes
among students.
The present data suggest that teachers tend to regard
alternatives as supplements to dissection. This may be because they make less
use of the more sophisticated technological innovations now available. Teachers'
limited use of alternatives implies that science methods courses in teacher
education institutions should include training in this area. This should
supplement current emphases on field-based and ecological study, as the focus
continues to shift away from the laboratory to the investigation of life in the
natural environment.
Note
1. Parts of this paper were presented at the annual conference,
Canadian Society for the Study of Education, Quebec City, 1989. Correspondence
should be sent to Alan D. Bowd, School of Education, Lakehead University,
Thunder Bay, Ontario, Canada P7B 5E1.
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