What We Know
Life science education includes the investigation of cells, organisms and
living systems and their characteristics, structures and functions. It also
includes interactions of living organisms with their physical environments
such as cycling of matter, flow of energy and community changes over time.
Life sciences in the Ohio Science Academic Content Standards include all of
the biological sciences and span elementary through secondary education.
What are some common misconceptions in life science and how can they be
addressed through teaching?
Wandersee, Mintzes and Novak (1994) have found that misconceptions commonly
held by students often mimic the explanations offered by early scientists.
Researchers have identified a number of common misconceptions in life science.
For example, Ozay and Oztas (2003) found that many ninth-grade students fail
to make connections between the processes of photosynthesis, plant nutrition
and respiration. Further, students may believe that plants are not alive and
do not reproduce (Wax & Stavy, 1989). Another common misconception is that
students often limit use of the term “animal” to vertebrates (Trowbridge &
Mintzes, 1988). Another study by Mintzes (1984) indicates that young students
have limited ideas about function and structure in organisms; for example,
many believe that blood is manufactured in the heart. Many students also hold
misconceptions about meiosis and mitosis, creating difficulties as they begin
to solve monohybrid or dihybrid genetics problems. One problem in addressing
misconceptions is that some are found in biology textbooks (Cho, Kahle &
Nordland, 1985). Teachers’ use of analogies and models in instruction also may
inadvertently lead to student misconceptions.
Misconceptions often are deep-seated and resistant to change (Ozay & Oztas;
Smith & Anderson, 1984). Wandersee et al. concur, stating that deeply rooted
misconceptions often provide a faulty framework for learning new concepts.
Sometimes students simply ignore information that does not fit into their
pre-existing knowledge. At other times evidence that contradicts what a
student already believes brings about cognitive conflict (Llewellyn, 2002).
Ideally, the discomfort resulting from uncertainty in understanding will cause
a student to reconstruct his or her framework of knowledge. When this occurs,
a student begins to incorporate new information and release the misconception.
Llewellyn suggests that individual writing assignments may reveal
misconceptions which can then be addressed.
Concept mapping may also help the teacher identify and correct student
misconceptions. Concept mapping is a procedure for helping students organize
concepts into meaningfully connected, as opposed to loosely connected,
entities (Novak, 1977). Concept maps depict the hierarchy as well as the
relationships among concepts. A completed map represents an understanding (or
any misunderstandings) of the relationships between sets of concepts and
efficiently relates this understanding to others. Concept mapping has spurred
a great deal of research in life science education. Generally, the research
concludes that concept maps enhance meaningful learning and help students
identify and correct previously held misconceptions. Stoddart, Abrams, Gasper
and Canaday (2000) find that concept maps also are an effective means of
assessing learning on multiple levels (Stoddart et al.) and offer a means to
lead students to take ownership of their own learning (Lunsford & Herzog,
1997). (For more information on the use of concept maps, see Classroom
Assessment in Science Education.)
What are the roles of investigations, experiments and laboratories in
teaching and learning life science?
In life science, as well as in physical and earth and space sciences, active
learning has been called scientific inquiry, investigation, experiment,
laboratory and practical work. All of these terms suggest learning in which
the student is actively involved in constructing his or her own understanding
of a concept or phenomenon. In trying to explain the difference between active
and passive learning in science, Arons (1976) coined the terms backwards
science and forwards science to distinguish science as commonly
taught in schools from science as done by scientists in their laboratories. In backwards
science, students are introduced to a concept’s terminology first,
followed by an appropriate supporting activity. Forwards science,
on the other hand, is the way scientists practice science, where questions
lead to investigations with terminology applied later. More recently, the
National Research Council (2000) stated that laboratory experiences should
allow students to “act like scientists” while solving problems.
The National Research Council (2000) concludes that laboratory activities in
our schools are limited and often “cookbook” in nature. That is, students do
not conduct scientific inquiry; rather, they follow a tightly prescribed set
of instructions to reach a forgone conclusion. Such laboratories are
illustrative rather than investigative. Discussing the research of Nachmias
and Linn (1987) as well as Smith and Anderson (1984), the National Research
Council cautions that without careful experimental design and thorough
discussion of laboratory findings, students may become confused and
discouraged. Appropriately designed laboratories, however, can:
Challenge students’ beliefs about the natural world and lead them to struggle
with alternative ideas until they are able to construct the concept accurately.
Help students generate knowledge directly from natural phenomena.
Produce lasting memory and, if followed by discussion, can lead to deep
understanding of the phenomena investigated.
Help students learn about precision and accuracy in observing, record keeping,
measuring, and inferring.
Involve students in solving problems (National Research Council, 2000).
Allen and Stroup (1993) indicate students should discover through repeated
experimentation (i.e., replication) that there is seldom one definite answer
from a scientific investigation. Another outcome of laboratories or
experiments is the discovery of anomalies. According to Echevarria (2003),
anomalous events, such as the birth of a white-eyed fruit fly offspring to
red-eyed parents, generate new explanations and ideas that must be
incorporated into the learner’s existing knowledge. This is very similar to
the process scientists engage in when confronted with new information. When
presented with an anomaly, life science students are more likely to experience
conceptual change if the information is both intelligible and plausible.
Strage and Bol (1996) suggest increasing the amount of time allocated for
active experimentation in life science as a way to increase participation by
students who are poorly motivated. They caution that often teachers use
teacher-centered instructional techniques and assign seat work to unmotivated
students, while more motivated students perform lab activities and are given
assessments involving problem-solving. In an investigation of high school
biology students, Von Secker and Lissitz (1999) found that an emphasis on
laboratory inquiry experiences was associated with higher and more equitable
science achievement. (For more information on issues of equity, see Equity
in Science Education).
Von Secker and Lissitz analyzed over 2000 tenth-grade student responses
(representing 163 schools) from the 1990 High School Effect Study. The data
were collected as part of the second wave of the National Education
Longitudinal Study (National Research Council, 1990) of the U.S. Department of
Education. A questionnaire asked teachers (most of whom taught biology) to
identify which composite best described their instruction: first,
teacher-directed or the extent to which they used teacher-centered instruction
(lecture, demonstrations, etc.); second, critical thinking or emphasis on
“habits of mind” associated with scientific literacy, such as understanding
and application of knowledge, ideas and scientific inquiry processes as well
as emphasis on scientific writing; and, third, laboratory emphasis or how
often teachers provided experiences for students to engage actively in
scientific inquiry. The influence of instructional practices on student
achievement was estimated across different schools. Von Secker and Lissitz
found that “Teacher-centered instruction is negatively associated with
achievement...on the other hand, mean science achievement is expected to
increase with the amount of emphasis on laboratory inquiry.” Further, they
found that “emphasizing laboratory inquiry had a small equity effect,” while
“emphasis on critical thinking was associated with a magnification of gender
and minority gaps.” They concluded that “De-emphasizing traditional,
teacher-centered instruction is expected to increase average science
achievement and minimize gaps in achievement between individuals of different
socioeconomic status.” (For more information on issues of equity, see Equity
in Science Education.)
What are the roles of scientific inquiry and critical thinking in life
Scientific inquiry and critical thinking are two ways of describing how
students learn and process knowledge. Scientific inquiry may be active and
done in a field or laboratory setting, but it also may involve reading, posing
questions and reflecting. Rodger Bybee (2002) recommends that teachers help
students become critical scientific thinkers by teaching life science through
inquiry. Through scientific inquiry, students learn the intricacies of
investigation including experimental design, data collection, data
interpretation and explanation, and defense of results. Germann (1991) also
stresses that teaching science through inquiry is essential to fostering in
students the ability to solve problems in a manner exemplified by scientists.
Scientific inquiry enables students to discover that answering one question
often leads to the development of new questions. (For more information on
teaching science through inquiry, see Scientific
An integral component of all learning is critical thinking, making connections
between new information and pre-existing knowledge and experiences. Allen and
Stroup suggest that helping students to consider, reason and distinguish valid
evidence from beliefs aids in developing critical thinking. Wright and
Govindarajan (1992) concur that encouraging critical thinking and providing
students the freedom to express ideas and decisions are important in life
science education. Their research suggests that the development of new ideas
is a continual process in which information taken from one study or
observation leads to new questions and deeper understandings. As students
mature, they also will recognize the difference between observations and
deductions that arise from observations. Wright and Govindarajan recommend
that students be taught to solve real-world problems and be given
opportunities to practice problem-solving in life science.