Dissection
as an Instructional Technique in Secondary Science: Choice and
Alternatives
Alan
D. Bowd 1
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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