K-8 PRESERVICE TEACHERS’ CONCEPTIONS ABOUT THE
IDENTIFICATION OF ORGANISMS AS INSECTS
Dr. Linda Schaffer,
Abstract<= o:p>
This
study used an insect survey task and semi-structured interviews to assess 98
preservice teachers’ conceptions of organisms they considered to be i=
nsects
and to identify the sources for their ideas. The results indicated that the stu=
dents
harbored a number of misconceptions about the identification of organisms as
insects and held non-scientific conceptions about what constitutes the class
Insecta. Most of them did not have an understanding of classification conce=
pts
in general. Correct scientific terminology was sometimes used, but incorrect
definitions or understandings were often associated with them. They focused=
on
visual cues and ignored scientific criteria. The students cited school, fam=
ily,
prior experiences and books as the sources for their ideas. The participants
thought that their school instruction about insects and other living organi=
sms
was inadequate and that concepts related to animals were learned in a rote
fashion.
Introduction
&nb=
sp; During
the past 30 years, much science education research has focused on the
conceptual learning process that lies behind student thinking concerning
natural phenomena and objects. In
an attempt to understand learners’ science ideas, researchers have
conducted studies which reveal that humans do not passively receive new
information, but actively generate their own meanings (Driver & Bell, 1=
986;
Osborne & Wittrock, 1983). Teachers are expected to facilitate the
generative process so students may build literate ideas about science topics
and processes (National Science Standards, 1996).
&nb=
sp; However,
research data imply that teachers have not been very successful at facilita=
ting
science learning. Teachers have been confounded when, despite their best
efforts, many of their students do not understand the fundamental concepts =
they
have covered in class (Gilbert, Osborne & Fensham, 1982; Tobin, Tippins
& Gallard, 1994). One rea=
son
for this is that students bring very strongly held personal conceptions into
the presumed that humans construct personal ideas through observant experie=
nces
from daily life in an attempt to explain the physical phenomena they encoun=
ter
(Clement, 1982; Nussbaum & Novak, 1976). Even when the ideas are scientific=
ally
flawed, they make sense to the learner and can be persistent (Ausubel, 1968;
Ausubel, Novak & Hanesian, 1978). Various terms have been used to descr=
ibe
the dissonant constructions, the most common being misconceptions an=
d alternative
conceptions.
There
is a growing concern that learners’ non-correspondent ideas have adve=
rse
effects on their knowledge acquisition and understanding of broad scientific
concepts (Hawkins, 1978; McDermott, 1991; Novak & Gowin, 1984). It is
theorized that when students hold alternative conceptions about its compone=
nts,
an alternative framework of the concept is developed (Adeniyi, 1985; Champa=
gne,
Gunstone, & Klopfer, 1983; Driver, 1981; Trowbridge & Mintzes, 1985=
). In order to preserve their personal
concepts, students may disregard anomalous observations and the teacherR=
17;s
ideas. They may also blend the
teacher’s or the scientific ideas with their alternative ideas, or use
the former concepts for school and their alternative ideas for the real wor=
ld.
Students sometimes misinterpret information presented by the teacher and us=
e it
to strengthen their own pre instructional conceptions (Gilbert, Osborne &am=
p;
Fensham, 1982).
=
Ausubel (1968) asserted that learning is affected tremendously by the
knowledge students possess before instruction. His claim led to other studi=
es,
the results of which indicate that in order to promote intended conceptual
change teachers must be aware of students’ ideas about a particular
subject (Hewson & Hewson, 1983; Osborne & Wittrock, 1983). If this =
is
really the situation in regard to learning, then it would make sense that
teachers take students’ ideas into consideration when planning
instructional activities so they may address and challenge specific alterna=
tive
conceptions. =
=
Unfortunately, teachers may hold many of the same mismatched ideas as
their students. Teachers’ misconceptions about natural phenomena, as =
well
as the language they use in the classroom, can actually promote alternative
conceptions in children (Ander=
son,
1990; Veiga, Costa Pereira, & Maskill, 1989). Those teachers most likely
will not recognize their students’ flawed ideas. Doubtless, some
alternative conceptions are more detrimental to a person’s understand=
ing
of scientific ideas than others, but the holding of any one may affect a
teacher’s ability to help students achieve accurate understandings of
science concepts. The teacher=
may repeat
what the textbook offers, skim the topic over, or eliminate it completely f=
rom
the curriculum. It is importa=
nt to
determine what misunderstandings teachers have in the areas they will be or=
are
teaching, since alternative conceptions may significantly diminish their
ability as facilitators. It has been suggested that ineffectively taught
college classes and poorly written textbooks contribute to students’
persistent misconceptions (Wandersee, 1988). Accordingly, educators who tea=
ch
science content to preservice teachers may want to reconsider the nature of
their own instructional strategies, or at least, they should attempt to find
out what knowledge prospective teachers bring with them to subject matter
courses (Tobin et al., 1994).
The results of several studies conc=
erning
students’ abilities to classify animals have elicited concern among
biology educators. The data imply that they have significant problems gr=
ouping
animals into major taxa and that the misclassification of animals is common=
in
all age groups, including preservice teachers and other college students
(Braund, 1991; Crawley & Arditzoglou, 1988; Ryman, 1974a; 1974b; Trowbr=
idge
& Mintzes, 1988). Recommendations for improving their students’
abilities to name, group and classify living things require the classroom
teacher to have a good understanding of classificatory schemes themselves a=
nd
to provide more in experiences with animals (Braund 1991; Trowbridge &
Mintzes, 1988). An obstacle to providing students with those types of animal
activities may be that teachers themselves have weak backgrounds in the dom=
ain.
When teachers are not able to classify animals into scientifically accepted
categories, it is reasonable to assume they will avoid lessons on taxonomy.=
While various dat=
a have
been published regarding content specific misconceptions in biology, few of=
the
studies regarding classification of animals has focused on a particular gro=
up.
Investigations of this sort may be helpful to teacher educators as well as
practicing teachers. The results could provide them with specific, concrete
examples of their particular misunderstandings, and may help them to become
aware of their students’ misconceptions.
&=
nbsp; It
is expected that most of these preservice teachers will enter the teaching
profession and most likely bring whatever alternative conceptions they have
about insects to the classroom.
They may not be successful at facilitating the learning of the
scientific viewpoint in their future students, unless they are provided with
information that provokes them to alter their current conceptions. Teaching the characteristics of an=
imal
groups, including insects, is common practice in elementary and middle scho=
ols.
While some concepts are complex and inappropriate for elementary or middle =
level
students (Dykstra, 1987), the identification of living organisms requires
skills that most young school age children possess. Accordingly, teachers
should have the capability to distinguish the organisms themselves. They must be able to provide stude=
nts
with a mental model of the taxonomic group, and devise a variety of situati=
ons
where they can observe the attributes that separate non-members of a group =
from
the members (Trowbridge & Mintzes, 1985). Vernacular misconceptions are
more easily overcome than others are, since the learner is not required to
deconstruct a complex framework of ideas. However, traditional teaching met=
hods
probably do not cause learners to discard misnomers. Rather, revealing
learners’ ideas and probing for their origins may have an enduring
effect. Informing prospective teachers about disparities between their own
views of insects and those of the scientific community may inspire them to =
plan
and implement effective intervention strategies when approaching the study =
of
insects with their students.
The
purpose of this study was to investigate preservice teachers’
interpretations of the insect class concept and to ascertain the sources of
their conceptions. Specifically, it examined two related lines of query: (a)
What concepts do preservice teachers hold regarding the classification of
organisms as insects, and, (b) what do they perceive as the sources of their
conceptions?
Definition
of Terms
&nb=
sp; Some
classification studies are limited in the scope of taxonomic concepts (Bell,
1981; Braund, 1998; Tamir, P.; Gal-Choppin, R.; & Nussimovitz, R., 1981=
),
while others explore several levels of taxa (Trowbridge and Mintzes, 1985;
1988). This study is different in that it focuses on one taxonomic group, t=
he
class Insecta. As previously
published studies contain a plethora of terms regarding learners’
personal ideas, and there is no clear agreement on specific meanings of the=
m,
this study will utilize the following terms and definitions to describe
preservice teachers’ ideas. The terms should be considered peculiar t=
o the
results of this study, and reflect the understanding of the investigator.
Biological terms reflect the scientifically accepted view for animal concep=
ts.
1.&n=
bsp;
2.&n=
bsp;
3.&n=
bsp;
4.&n=
bsp;
5. &n=
bsp;
concept
that are not in agreement with scientific thought.
It
has been suggested that the term misconception implies a mistake and that t=
he
term alternative conception may indicate the sum of various subordinate
misunderstandings for a particular concept. For that reason, individual
incorrect responses, that may or may not be typical of the participant̵=
7;s
conceptual schema for the class concept of insect, were classified as
misconceptions. Incorrect responses that do not receive high confidence sco=
res
may be guesses. Therefore, they were labeled misclassifications.
Methodology
The participants in =
this
study were 98, K-8 preservice teachers at a large southwestern state univer=
sity.
The sample was by convenience, and consisted of all of the students attendi=
ng
fall semester science methods courses.
A
mixed design was employed in order to answer the questions posed. First a
survey was given that included an insect task as well as some multiple choi=
ce
and open-ended questions, and later, 14 semi-structured interviews were
conducted with a random sample of volunteers from the survey population.
Several
sub questions were used to focus the collection of data. They were:<=
span
style=3D'mso-bidi-font-size:12.0pt;line-height:200%;font-family:"Times New =
Roman";
mso-bidi-font-family:"Courier New"'>
&=
nbsp; The
survey task was designed to answer questions one through five, and the
interviews addressed questions five through eight. The questions posed duri=
ng
the interviews allowed the students to elaborate on their task answers, to
provide details concerning their ways of thinking about insects and to just=
ify
the choices they made on the task. They were also able to provide details a=
bout
the sources of their conceptions. Each interview lasted approximately 15
minutes and the following questions were asked:
The
students were shown their survey task, and depending on their answers they =
were
asked neither, one, or both of the following two questions (4 and 5):
All
students were asked questions 6-8.
In
response to the students’ comments, other questions were posed during=
the
interviews.
Data Analysis
The following data were collected:
1.&n=
bsp;
Student
task scores from individual survey forms,
2.&n=
bsp;
Confidence
score (of 1-4) for each response on individual survey forms,
3.&n=
bsp;
Item
(by organism) task scores from all survey forms,
4.&n=
bsp;
Mean
confidence score for each organism from all survey forms,
5.&n=
bsp;
Lists
of reported criteria that students used to make identifications of insects =
and
non-insects from all survey forms,
6.&n=
bsp;
Lists
of reported sources for students’ insect concepts from all survey for=
ms,
7.&n=
bsp;
Demographic
data, including numbers of life science classes taken in grades 6 - univers=
ity
level and ethnicity.
&=
nbsp; The
task survey data were analyzed by computing percentage scores for each
participant. Individual incorrect answers were paired with confidence scores
and identified as either guesses or personal misconceptions. Items (organis=
ms)
that received incorrect responses by at least 20% of the participants, and
received a mean confidence score of above 2.5 were labeled popular
misconceptions.
Lists of identification criteria we=
re
made and reported by frequency of their appearance on the surveys. These we=
re
used during the interviews, to gain information about the participants thin=
king
when they justified choices they had made on the survey task. Additionally,=
the
students’ reported sources for their insect class concepts were taken
from each survey, and tabulated in order of frequency.
Discussion of Results
&nb=
sp; In
the following section, the findings and their interpretation are discussed
question by question.
Questions 1: What percentage of the
preservice teachers is able to identify organisms that do or do not belong =
to
the class, Insecta?
<=
span
style=3D'mso-tab-count:1'> &=
nbsp; The
preservice teachers’ mean score on the classification task was 85.5%.=
The
scores ranged from 100% to 68%. Ten of the students (10%) selected all
organisms correctly, for a score of 100%. Thirty-one students scored above =
90%,
sixty-one scored between 77% and 88%, and six scored below 75%. If
non-arthropods (worms, reptiles, amphibians, and birds) are removed from the
scoring, the range of scores becomes 100% to 59%, and the mean 82%. The sco=
res
indicate that most of the students neither over nor undergeneralize greatly,
but only a small percentage of them knows and can correctly apply the
scientific criterion of six legs to identify members of the insect class. F=
or
the most part, they do not consider animals with backbones insects. This was
indicated on the survey by many participants who said that they clearly
eliminated organisms that fit into one or more of the classes representing =
the
vertebrates. Seventeen of the preservice teachers scored in what is conside=
red
the average range (70-80%). Almost half of all the students (46) scored in =
the
average range when non-arthropods are eliminated from the scoring.
Students who missed only a few ite=
ms on
the survey task may have done so through confusion about the illustrations.
But, while a score of 80-90% is normally considered a “good gradeR=
21;,
on the survey it can demonstrate that the recipient holds a non-scientific
concept of insects. For example, if a student thought that spiders were
insects, and made no other errors, they would have scored an “A”=
; on
the task. That person would still not have a correct concept of insects.
These results are by no means a re=
ason
for great concern, but hopefully, those individuals who scored in the avera=
ge
or below average range will gain more knowledge about the arthropods before
attempting to teach a unit to their future students. Otherwise, they will n=
ot
be effective in their endeavor to pass on accurate concepts.
Question 2: How confident are the
preservice teachers in their identifications of examples and non-examples of
insects?
There were a large number of perso=
nal
misconceptions (incorrect response with a confidence level of 3 or 4) held =
by
the preservice teachers. Eighty-four percent of the participants held one o=
r more,
for a total of 329 individual answers that were judged to be personal
misconceptions. Eighty-two students held from 1 – 10 misconceptions, =
the
average being 4.1.
It really is not possibly to relat=
e the
specific numbers of students’ misconceptions in this study to those in
others, for a few reasons. First of all, the criteria for what constitutes a
misconception vary among the previous studies. None of the reviewed works w=
ere
specific to the insect class, so comparisons may only be made in relation t=
o a
few organisms included in those studies. On the other hand, the results of
cross-age studies that included college students suggest that the frequency=
of
misclassifications among that group is considerable (Trowbridge & Mintz=
es,
1988). Since it is unlikely that new teachers will be aware of their specif=
ic
misunderstandings, it is up to university level science teachers to become
conscious of the beliefs that their students hold, so that the cycle of
misunderstandings can be broken before those preservice teachers become
facilitators of science learning in their own classrooms.
Question
3: Which organisms pose the greatest difficulty for the preservice teachers=
on
classification tasks?
There is no clear agreement about =
what
constitutes a misconception for a specific item on a survey task. Some
investigators have identified them as incorrect answers chosen by at least =
10%
(Ryman, 1974; Trowbridge & Mintzes, 1985; Trowbridge & Mintzes 1988=
) or
15% (Braund, 1991) of the participants, while others labeled responses that
were given by more than the number of people expected by chance (Crawley and
Arditzoglou, 1988). This study identifies popular misconceptions from the
classification task as incorrect answers that were chosen by at least 20% of
the participants, and received a mean confidence score of above 2.5. Those
organisms were considered troublesome for the students, and a few of them w=
ere
found similarly so in other studies. Thirty-one of the 35 organisms were
identified as personal misconceptions for one or more students, and eight of
them, all invertebrates, qualified as popular misconceptions. With the
exception of the earthworm, the other organisms were arthropods. The isopod=
(commonly
roly-poly or woodlouse), spider and centipede were identified as misconcept=
ions
in about the same percentages as in previous elementary and cross age studi=
es
(Ryman 1974; Braund (1991). The butterfly and earthworm have also been
previously cited as common misconceptions, but not in percentages as high a=
s in
this study. The millipede and pseudoscorpion, identified as popular
misconceptions for students in this study, were not reported as such in oth=
er
studies that were reviewed.
It is common that
researchers urge teachers or teacher educators to use the results of classi=
fication
studies in order to plan instruction, so that their students’ prior
concepts are revealed, and some sort of process to correct erroneous ideas =
is
undertaken. Considering that the students in this study held some of the ve=
ry
same concepts found 12 to 28 years ago, it is not likely that the research =
data
have been considered, at least not by the educators of the preservice teach=
ers
who participated. I believe that is unfortunate, since the concepts covered=
are
probably not difficult to remedy, given time and specific instructional
techniques. Those instructional practices have been previously suggested:
earlier and more experiences with animals as well as practice with examples=
and
non-examples (Gagne, 1970; Markle, 1975).
Twenty of the organisms on the surv=
ey
task were insects and sixteen were not. The insects received 124 of the 329
instances of personal misconceptions while the non-insects received 205. Se=
ven
of the organisms identified as troublesome popular misconceptions for the
students were non-insects, compared to only one insect, the butterfly. The
preservice teachers in this study overgeneralized far more than
undergeneralized to the class. This may be due to the personal concepts that
the students have regarding the insects -- that they crawl on the ground, h=
ave
many legs, and possess some sort of hard covering. Trowbridge & Mintzes=
(1985) called concepts of animal gr=
oups
that are greatly overgeneralized to, “garbage cans”. Braund (19=
91)
thought that children’s insect concepts fit with that
characterization.
Question 4: What percentage of the
preservice teachers who state that they applied the accepted scientific
criterion of the insect group (six legs, under natural conditions) to inclu=
de
or exclude organisms on the survey, select organisms that violate that
standard?
In determining the answer to this
question, many ideas emerged from the survey and interview data regarding t=
he
preservice teachers’ thinking about insects and how they apply their
knowledge. For that reason, I have spent more time on, and provided more
interview details about the subject of this question.
The scientific definition for a me=
mber
of the class Insecta usually includes a fairly complete description of a
generalized insect. It is typically described as an organism that as an adu=
lt
has six legs and three body parts. Most, but not all, possess wings and alm=
ost
all have antennae. Only one of the descriptors -- has six legs -- can
stand alone to describe an insect. Thirty-six students said that they used =
that
criterion only or combined with other characteristics to identify insects.
There were 43 other individual comments about legs, some general, like
“the number of legs” and others specific but not correct, like
“not more than 8 legs”. By far, legs were the most commonly cit=
ed
criterion, followed by “antennae” and “prior
knowledge/looks-like”. Other than the prior knowledge/looks-like
categories of answers, the individual characteristics used by scientists or=
in
school were given more frequently than other ideas. This indicates that the
students had encountered the scientific definition of insects either through
school instruction or elsewhere.
<=
span
style=3D'mso-spacerun:yes'> Had students who indica=
ted
the use of the criterion of six legs on the survey task applied that charac=
teristic
in each case; theoretically, they would have scored 100% on the task. At le=
ast
any organism with more than six legs would have been eliminated. In this st=
udy,
only eight, or 22% of the thirty-six individuals who claimed to have used s=
ix
legs scored 100% on the task. Twenty-eight (78%) chose organisms that have =
more
than six legs, excluded insects, or both. Students who did not use that
criterion would not necessarily be expected to know the insects compared to
other groups. But, for those participants who did, it was important to
determine how their other conceptions might have interfered with decisions =
made
during the survey task.
The
interview data revealed some idiosyncratic and important concepts held by t=
he
students, most of them previously reported in other classification studies.=
One
pervasive idea is the concept that insects are creepy and crawly. The belief
was used by at least half of all of the interviewees to justify answers that
defied their stated criteria. Unless that characteristic was intended by the
statements “prior knowledge or looks-like”, it was not mentioned
one time on the survey. The following excerpt from one interview illustrates
how that concept interfered with the student making correct choices:
I remembe=
r when
it came to the fly, mosquitoes, and bees that I really didn’t know wh=
at
they were. I didn’t know if they were in a class of their own. I think
that I have a prejudice about insects. When I think about an insect I think
about something that creeps and crawls, so when it came to something that
flies, I didn’t know.
=
After
pointing out to the student that she had correctly identified the dragonfly=
as
an insect she exclaimed, “I did the dragonfly! I guess I’m not
consistent.”
=
In one
interview a student who had used the scientific definition of an insect for
categorization purposes explains her thinking for the choices she made. This
participant did not select any organisms with more than six legs as insects,
but excluded some that did.
=
Interviewer=
: You
indicated that insects have six legs. Here is a flea. Can you count the leg=
s on
this?
=
Interviewee=
: Yes,
there are six.
=
Interviewer=
: Why
didn’t you choose the flea as an insect?
Interv=
iewee: I tend to think of insects as cra=
wly
bugs, and the flea jumps. Interviewer: This is a butterfly; can you =
tell
me about that? =
&nb=
sp;
Interviewee: I guess because it flies. I think it is interest=
ing
that I said insects have six legs, but when I looked at them I didn’t=
pay
any attention to that.
A few important points come from these
students’ discourses. One is that, like the students in earlier studi=
es,
these preservice teachers hold the concept that that insects creep and craw=
l.
Another is that, despite having scientific information about the identifica=
tion
of insects, the students relied on other visual cues to make their final
decisions. They eliminated some organisms regardless of the presence of six
legs.
Arnaudin and Mintzes (1985) called ideas
that are constant across grade levels stable alternative conceptions.
Considering that many of the preservice teachers’ idea that all insec=
ts
crawl was still held at the university level, I consider that concept a sta=
ble
alternative conception.
Some science educators have stressed that the pervasive practice of =
rote
learning in schools does not promote the kind of thinking necessary for
students to develop good classification skills. The prerequisite knowledge =
that
students must possess in order to make comparisons when classifying organis=
ms
includes clear and precise definitions for the taxonomic group. When rote
learning occurs, definitions are memorized but forgotten if they are not
applied in a variety of situations, particularly using examples and
non-examples. The references to “six legs” imply that the prese=
rvice
teachers had at least memorized the definition for insects. The number of
incorrect choices those students made suggests that, at the time, the
definition was not applied with examples and non-examples, or at least
memorized out of the context of comparing animal groups. It appears that mo=
st
of the preservice teachers did not possess precise, scientific mental models
for the insect class. For this reason, I believe that they depended upon vi=
sual
cues that developed from earlier out-of-school experiences.
The
gist of the comment “…when I looked at them I didn’t pay =
any
attention to that”, was repeated by other students; almost half of th=
em
alluded to the fact that for them it was really a “visual thing”=
;.
Several students mentioned that the presence of “a hard shell” =
was
an insect trait. That may be one reason why students have often thought the
isopod is an insect. The exoskeleton is reminiscent of some beetles, and
despite the presence of many small legs, for them, the visual stimulus of t=
he
“hard shell” outweighed the overabundance of legs.
=
It should be noted that some students were not consistent in applying
even their personal misconceptions about what is an insect. The participant=
who
chose the dragonfly, in spite of its aerial habit, was not the only intervi=
ewee
to recognize the contradiction of his or her own comments. One student, who=
was
not consistent in applying her stated criteria, even though her concepts we=
re
not scientifically acceptable, had remembered that insects have three body
parts, and used that to choose a non-insect:
=
Interviewer:
These are the criteria you used to identify organisms as insects. They have
more than four legs, most have antennae, and they are relatively small and =
have
little or no body hair.
=
Interviewee=
: Yes
=
Interviewee=
: Look
at number five [earthworm].
=
Interviewee:
Doesn’t have legs, antennae, but I don’t know what it would be
classified as.
=
Interviewer=
: What
were you thinking about when you considered the earthworm an insect?
=
Interviewee=
: I
was considering the three body parts, the head, the thorax, and the bottom
part. I didn’t put three body parts in my classification, because in =
my
opinion it didn’t match with some insects.
=
=
Interestingly,
while she used that characteristic to include a non-member, she excluded th=
ree
body parts from her written criteria on the task because in her opinion
“it didn’t match with some insects.” She also ignored her
statement that insects have more than four legs. This shows that the student
has a great deal of confusion regarding her classification criteria.
=
=
<=
/span>In
contrast to the confusion that the person in the previous example demonstra=
ted,
another student who correctly selected all of the organisms on the survey w=
as
clear about the application of his stated criteria. He used the characteris=
tics
of “six legs or three body parts” to separate the insects from =
all
the other organisms. I asked him, “What if an organism had three body
parts, but more than six legs?” He said, I wouldn’t call it an
insect; it would have to fit both criteria.” This person had scientif=
ic
ideas about what animals are insects, and was able to apply them without
exception.
&=
nbsp; One idea revealed during two of the
interviews and on one survey question was unexpected. It is so common to te=
ach
the life cycle of a butterfly in elementary school, that I am tempted to use
the term, universal, to describe the practice. Of all the organisms on the
survey, students may have had the most experience with the butterfly. While
many students in previous studies did not consider the butterfly an insect,=
I
assumed that it had to do with the presence of wings, since the authors said
that the students conceptualized insects as crawly organisms. In this study,
two of the interviewees justified their answers using that reason. But two
others gave different explanations. These interviewees did not consider
butterflies insects, even though they believed that six-legged organisms are
insects, and that adult butterflies have six legs. One discussion went like
this:
Interviewer: Tell me about the butterfly.
Interviewee: I know they go through metamorpho=
sis,
before they become butterflies- that they are caterpillars with more than s=
ix
legs.
Interviewer: Have you ever seen caterpillars&#=
8217;
legs?
Interviewee: I don’t recall.
Interviewer: Do you remember studying the
caterpillar as a child in elementary school?
Interviewee: Yes, the pupa, the larva, they ta=
lk
about the change of it more than the actual qualifications of an insect.
During the interview another partic=
ipant,
through personal observations, recalled the particulars of the pseudopod=
s
(pro legs) of a caterpillar:
Interviewee: I thought the butterfly was an in=
sect,
and the reason I decided the butterfly wasn’t an insect was because of
the caterpillar form. Interviewer: Can you tell me more about that? =
Interviewee: A caterpillar has more than six l=
egs,
so it isn’t an insect to me. And yet a butterfly does have six legs, =
so
it is an insect, so I really couldn’t decide.
Interviewer: What do the [caterpillars] legs l=
ook
like?
Interviewee: Not like an insect’s.
The student then describes the pseu=
dopods
of the caterpillar in almost perfect detail. She exclaims:
Interviewee: Oh, they aren’t legs at all=
!
Interviewer: Do you think you ever studied
metamorphosis of insects, like the changes they undergo from juveniles to
adults?
Interviewee: Yes, I did.
Interviewer: Have you ever examined a butterfly
before?
Interviewee: Yes.
Interviewer: How many legs do they have?
Interviewee: I think they have six.
A third student, who correctly classified al=
l of
the organisms except for the butterfly, wrote on the survey form;
“Anything with six legs was an insect. The butterfly changed, but was
never an insect.”
Shepardson (1997)
thought that students had a constrained view of metamorphosis due to the
singular use of the butterfly to demonstrate insect life cycles. Conversati=
ons
with the two students mentioned above indicate that there may not be a link
between the early instruction using butterflies as examples and the
identification of them as insects at all. It also supports the idea that
science concepts taught in elementary school may be too narrow in scope or
lacking in depth. While it is necessary and important for teachers to
demonstrate concepts such as life cycles with particular organisms (and ins=
ects
are readily available, successful in the classroom environment, and many
display markedly different forms during metamorphosis), it appears that
discussions and/or activities related to the understanding of insects as a
taxonomic group were absent or unproductively brief. One might conclude that
this is true for most groups of organisms studied in school, with the possi=
ble
exception of humans.
&nb=
sp; It
is likely that many students who use criteria for the identification of
organisms may not actually understand the scientific concept of using those
traits in classification systems. While models for classification of organi=
sms
change as new information is revealed, generally organisms may be included =
or
eliminated based on specific morphological characteristics. &=
nbsp; The
ideas revealed in this study are consistent with data from earlier studies:
that students rely on visual cues, rather that scientific classification
criteria (Natadze, 1963, Trowbridge and Mintzes, 1985; Braund, 1991) and th=
at
they conceptualize insects as creepy-crawly organisms (Ryman, 1974; Braund,
1991). This brings up a couple of questions that might be worth considerati=
on
by the science education community. One is: Have we paid enough attention to
the results of earlier studies regarding students’ personal ideas? The
other may be far more important: Are we teaching science in a way that prov=
ides
our students with the skills they need to systematically apply the principl=
es
of classification, or for that matter, any other science concept?
Question
5: What do the preservice teachers perceive as the sources for their
conceptions of insect class members?
Seventeen
categories of sources of the students’ concepts were taken from the
surveys: Eight from the multiple-choice questions, and nine self reported.
School was the most frequently cited (82 instances) followed by television
(47), books (41), and family (26). While only seven students mentioned dire=
ct
observation, it was cited fairly often during the interviews. One intention=
of this
study was to examine sources and look for their potential relationships to =
the
students’ abilities to identify insects, but that was not possible. T=
he
sample size was not large enough for both the scoring groups and the source
categories. Also, to complicate the issue, most of the participants cited m=
ore
than one source. While I will=
not
attempt to suggest a particular relationship here, it was interesting that =
two
students who scored 100% on the survey task, referred to recent activities
where they had to apply accurate concepts about insects for summer jobs. One
worked in a laboratory, sorting mosquitoes, and the other worked on an exhi=
bit
at the zoo. It is likely that the experience with examples and non-examples=
of
insects helped them to attain scientific conceptions.