Constructivism and Alternative Conceptions in Chemistry
Alternative conceptions are those concepts that do not agree with those accepted by the academic
community; e.g., the scientific or chemistry community. Alternative conceptions are also called
pre-conceptions and mis-conceptions. Some examples of alternative conceptions identified by
education research include:
heavier objects fall faster than light objects
the direction of force on a projected object is always in the direction of motion
the mass of a tree comes from the nutrients extracted from the ground
a continuously applied force results, eventually in a maximum speed
attractive force by the nucleus is shared among the electrons
sodium fluoride is made up of sodium and fluorine
Cause and effect research, correlational research and anecdotal evidence all agree that alternative
conceptions are created early in life and are very hard to change. The area of education research
that studies this phenomenon is called constructivism; i.e., the construction of concepts--
alternative or otherwise. The basic idea of constructivism is that learners are not ‘blank slates’
or ‘empty cups’ to be filled with knowledge, but that they already have a huge body of
knowledge and life experience. Knowledge is constructed within the individual learner--
regardless of the group teaching that is done and regardless of the assumed learning that is
occurring. There are a variety of kinds of constructivism that are advocated by different
education researchers and learning psychologists. However, the basic advice to teachers are
fairly common; e.g.,
Students should be actively engaged in their learning, rather than passively receiving.
Learning should begin from ‘where students are’ in their knowledge.
Science students need opportunities to test their knowledge frameworks against other
knowledge and against the physical world. (See Popperian falsification as part of the Create-Test-
Use section of the www.CRYSTALAlberta.ca Outreach website.)
It is important for teachers to understand, as far as possible, their students’ ‘prior knowledge’ –
what the students already bring to class in their minds. In this context, knowledge should be
understood as a rich, complex network, rather than as a simple list of ‘school facts’ already
A constructivist lesson plan needs to allow students the opportunity to safely (without
embarrassment) express their alternative conceptions and to test these conceptions (not just the
conceptions accepted by the scientific community). For example, research indicates that students
may provide an answer in a test indicating that all objects (ignoring friction) fall at the same
acceleration (or with the same time from the same height). However, when asked either years
later or asked out of the classroom setting, their original conception persists (i.e., that heavy
objects when dropped from the same height will hit the ground at the same time).
See the PowerPoint file below and also the sample constructivist lesson plan for more detail.
Constructivism is one of those counterintuitive ideas that need time to sink in--it needs to go
slowly through the phases of awareness, understanding and action. Try to remember this in your
everyday classroom teaching.