The Earth Scientist

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The Earth Scientist
Using student alternative conceptions in instruction
Using knowledge about student alternative conceptions to help students uncover their own ideas
may be the most powerful, and simple, use of conceptions research (Strike and Posner, 1992;
diSessa, 2006; Aikenhead & Jegede, 1999). We suggest that encouraging students to draw, write, and
talk about ideas is vital for encouraging students to evaluate and rethink their alternative conceptions.
Teachers can utilize these techniques at the beginning of a school year, or during instruction
as a way to introduce a new subject. By determining what students think prior to instruction,
teachers will gain an understanding of their students’ strengths, as well as those areas that need to
be addressed in order for students to grasp geophysics concepts. With this knowledge, teachers can
tailor their instruction to build upon student strengths and address areas of difficulty.
Figure 1. An example student
drawing related to the structure
of Earth’s interior. The student
was prompted to draw a model
of the Earth’s interior, including
the source of lava. Drawings
such as this can be used to
scaffold to other ideas about
geophysics. For example,
placement of earthquake wave
ray paths within the context
of this model would either
challenge the student’s model
or provide additional insight into
alternative conceptions about
earthquakes.
The approach used to encourage students to think deeply about their
own ideas depends on student age, as many approaches that might be
used for older students are inappropriate for students that are much
younger. However, we have found that methods used with younger
students are actually quite effective for use with older students, even
those in advanced secondary or college courses. Ideas held by younger
students, particularly those who are just beginning to write and read,
can be illuminated through drawings (Fig. 1) and classroom discussion.
In the geosciences, for example, drawings have been used across
many age groups to investigate plate tectonic and related conceptions
(e.g., Gobert, 2000; Sibley, 2005). We note that understanding how a
scientist illustrates a concept is an important step to using student
drawings to identify concepts that might need additional discussion
in the classroom. Student drawings can be compared to scientific
models, such as those available through the U.S. Geological Survey
(e.g.., http://pubs.usgs.gov/gip/dynamic/dynamic.html). We also
recommend asking a scientist to make a drawing for you. Overall, we
have found that geologists are more than willing to assist us in classroom instruction or research by
providing their own responses to the types of questions we generally ask students.
Although drawings provide excellent opportunities for students to express their conceptual understanding,
subsequent classroom discussion, one-on-one conversation, in-class questions (Fig. 2),
or other opportunities for students to verbally explore their ideas gives both students and teachers
insight into concepts that are difficult to understand. Verbal expression of ideas gives students the
opportunity to learn from one another, and become more confident in their own knowledge as
they use it to help a classmate. By posing questions to students in class, having them make predictions
about geophysical processes, and allowing them to manipulate and/or collect geophysical
data, students have the opportunity to challenge their own ideas and gather evidence that supports
scientific thinking. A good example of an activity that provides students with the opportunity
to construct their own knowledge is Sawyer’s “Discovering Plate Boundaries” activity (http://
plateboundary.rice.edu/intro.html). This exercise provides students with opportunities to make
predictions about where tectonic plate boundaries should occur, and to use geophysical and other
evidence to reason to the plate tectonic model. In our own instruction with undergraduate nonmajors,
we use this activity after first prompting students to draw pictures of tectonic plates and
provide written explanations for plate tectonic phenomena. We follow the activity with additional
probing about student ideas, giving us insight into concepts that might need additional attention.
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