Science Teaching & Learning
Welcome! This page provides perspectives and practices useful for helping students to learn ideas about topics in school science & technology. "Learning Ideas" is the second of three phases in my framework for students' 'conceptual' education; that is, for encouraging them to reconstruct their conceptions about 'products' (e.g., laws & theories) of science & technology. If you have ideas, questions, comments, etc. about anything here, write to me.
"Learning Ideas" refers to opportunities often arranged by the teacher for students to learn ideas (e.g., laws & theories) that might benefit them now and in future. Which 'ideas' may benefit students is contentious - giving that students' lives are complex and different and that it is hard to predict their futures, and considering that there are competing reform views. A key issue about Learning Ideas, however, pertains to levels of teacher and student control of learning. I contend that teachers should try to control learning when pre- determined ideas are to be learned.
|Rationale for Teacher
Control of Learning
Before there was much formal schooling and, indeed, before children enter school, people were able to learn a great deal. Children can learn by imitating family members and friends. They listen to conversations and they learn from their mistakes. Generally, this sort of learning is inductive - which refers to the development of general ideas from specific observations. Closely related to this is abductive thinking, which involves reasoning to arrive at probable explanations for phenomena. Because both of these forms of reasoning are theory-dependent, it is difficult for learners to discover ideas they don't already have ideas about. It is particulary difficult for learners to learn pre-determined ideas. Learners generally need to be told or have read about specific new ideas. A relevent joke goes something like this: 'You can either read Shakespeare or wait for a chicken to peck it out on a typewriter.' In science & technology education, because of the vastness of its knowledge, it is particularly important that learners have direct, systematic instruction. It also is imperative that they gain access to science & technology knowledge because of the great influence these fields have on societies. Suggestions for such systematic instruction are provided below. Through instruction, students should have well developed understandings of new ideas. What they believe, on the other hand, can be settled by them through student-directed, open-ended inquires - through the Judging Ideas phase of my approach.
There are many approaches for teaching students 'content' (i.e., 'products' of science and technology, such as laws, theories and inventions). Many of these, such as those those at 'Teaching,' apply as well to science and technology education as they do to teaching and learning in any other subject(s). Other approaches - such as 'guided empirical activities' - tend to be used more frequently in science and technology education than in other areas of learning. The suggestions for teaching below are based on research on human learning, including constructivism.
i.e., Interative Teacher Demonstrations and Guided Empirical Activities.
Interactive teacher demonstrations, in which teachers engage students in question - response sequences while they conduct an activity for the students, are can be very effective. Questioning is similar to that in Socratic Instruction. Often, demonstrations with concrete phenomena and/or visual aids, etc. involve Aristotelian Logic; i.e., cycles between inductive (developing general ideas - such as hypotheses & predictions - from specific experiences) and deductive thinking (testing general ideas with specific experiences). Based on the model at right, teachers can encourage students to explore cause-result variables, with hypotheses, as the demonstration proceeds.
|Heat Transfer Demonstration
Purpose: to illustrate and explain the idea of movement of heat along a length of metal.
1. Set up the apparatus at left (paper clips are stuck to the rod with melted wax).
2. Ask students to suggest what might happen to the clips, and for what reason, as one end of the rod is heated. (Then, heat the rod.)
3. Ask the students why the results may have occurred. Teachers can let students know that scientists would explain that the clips drop off one after the other because heat makes tiny unseen particles vibrate along the length of the rod, passing heat on from particle to particle.
Note: A possible WISE Problem connection is to relate this to geothermal heating as an alternative to burning of fossil fuels.
|Air Expansion Demonstration
Purpose: to demonstrate the idea that air takes up more space when heated, a situation which can be explained by suggesting that particles of air move farther apart when heated.
1. Set up the apparatus as illustrated at right. Do not heat the flask immediately.
2. After explaining the set-up to students, ask them what might happen to the balloon if the flask is heated. (Then, heat the flask and ask the students to explain their observations.)
3. Explain that heat makes the balloon inflate because invisible air particles move faster and farther apart (filling the balloon) as they gain heat energy.
Note: A possible WISE Problem connection is to relate this to
Purpose: to demonstrate that carbon dioxide is a gas heavier than air, and that it does not support burning.
1. Light a small candle, melt it to aluminum foil, and rest it in the bottom of a tallish beaker.
2. Mix a small amount of baking soda and vinegar in a flask, and ask students what will happen to the CO2 (which you can say is released) when the flask is tipped over the beaker.
3. 'Pour' the (invisible) gas over the flame. Explain that the flame goes out because CO2 pushes oxygen away from the flame and because CO2 is heavier than air, making it fall.
Note: A possible WISE Problem connection is to relate this to
|An interesting and eclectic
series of teacher demonstrations are given
through the links at right. Each one was
performed by student-teachers in a secondary
science teacher education programme. No school
students were involved. So, these do not show
how dynamic such demonstrations can be with
students; but, they do provide some insights
into particular techniques that may be useful
for science teacher demonstrations. Of course,
teachers can - and probably should - adapt such
demonstrations to suit conditions in their
Photosynthesis Energy Transfer.
Effects of pH Changes.
Single & Double Displacement Reactions.
are, for many educators, an essential component of
any science (or technology) programme. There are,
however, numerous potential problems associated with
labs, in which students are expected to 'discover'
and/or to 'inquire into' phenomena and arrive at
particular pre-determined conclusions, are highly
problematic. It is apparent that they likely are
discriminatory, since disadvantaged students (e.g.,
from lower socio-economic groups) are less likely to
have appropriate notions about what they are
expected to discover and, therefore, are less likely
to discover them than advantaged students.
Meanwhile, there is research supporting the idea
that discovery/inquiry labs cause students to
inappropriately conclude that science is an
empiricist-inductive process, devoid of possible
influence by theoretical conceptions or ideologies.
For at least these two reasons, I recommend that
teachers avoid inductive discovery/inquiry labs when
the purpose is to teach pre-determined laws and
practical activities - in which students evaluate
(often using empirical tests) ideas about which they
have been taught - would be much better, although
not without issues, as well. These 'confirmatory'
activities (i.e., getting data to confirm laws or
theories) tend to cause students to conclude that
scientific knowledge building is a
'hypothetico-deductive' process, as Karl Popper had
suggested. This avoids, however, the strong role
that psychological, sociological, economic, and
gender factors play in influencing scientists and
technologists' conclusions. To overcome this
problem, teachers need to include in their
programmes instruction about the nature of science
and technology. Suggestions about this are provided
Learning. Also, they should regularly remind
students of some basic tenets
of the nature of science (e.g., NoS)
while they are engaged in practical activities.
Sources of labs are provided via the links below.
Web-based Instructional Resources for
Science & Technology (S&T) Education
In support of perspectives and resources provided on this page, links to relevant resources are given at right. Note that these categories are artificially separate. There may be inconsistencies and overlaps. If you have any comments, suggestions, and/or recommended websites, contact me.
Student Assessment & Evaluation
|There are benefits to
assessment (gathering achievement data) and evaluation
(judging the merits of such achievement). Research
suggests, for example, that regular feedback assists
students with their learning, partly because of its role
that is, thinking about and understanding their learning
and being able to take action to improve it. At the same
time, there are serious concerns regarding assessment
and evaluation. Because science and technology are so
economically important, a particularly troubling issue
relates to the importance of topics to be assessed. In
other words, just how important is it for students to
learn what is prescribed for them in science and
technology curricula? To what extent are those curricula
designed to benefit them, as opposed to those who most
influence curriculum making? I believe that,
unfortunately, science curricula in many jurisdictions
are engineered to benefit the most influential members
of society to a much greater extent than those to be
educated. It is apparent to me (and to many others) that
school science systems primarily serve interests of
business and industry. Some elaborations of my positions
are provided @ Educational
S&T Literacy, and Status/Reform of Science
Education. In light
of these concerns, I believe organized education needs
to be restructured in ways that provide every individual
with resources necessary for a happy and healthy life,
including fulfilling participation in healthy societies
and environments. Some suggestions for such reform are
provided @ Enlightening
& Empowering S&T Ed. Some suggestions
for assessment and evaluation in science education
based on these issues are provided at right.
More Democratic Assessment & Evaluation in S&T Education