A Teaching Sequence: Science is Tentative
The learners
This program is targeted at a mixed-ability co-ed class of year 10 students in a decile 7 Auckland
secondary school. They are doing an earth science unit and have already looked at the internal
structure of the earth, crustal features (mountain ranges, continents, oceans), earthquakes (how
they happen, events in New Zealand and worldwide), volcanoes (how they happen, events in New
Zealand and world-wide) and fossils (how they are made, types, dating). This sequence of lessons
starts to pull all this together as it develops the theory of plate tectonics.
The teaching sequence
I wanted to look at how scientific theories change (Nature of Science, NoS), but that hinges on
evidence so I needed to start with an aspect of earth science that linked well to evidence. Volcanoes
would have been more relevant to students but I could not find a clear enough link with evidence. A
recent New Zealand Herald article talked about where lava would flow if Auckland had another
eruption, but I could not find the evidence I could use effectively in the classroom that Auckland
would have another eruption. While Italian scientists have recently been convicted for not predicting
a fatal earthquake, evidence from which to predict earhquakes with certainty does not exist. That
took me back to fossils.
The need for evidence was followed by Wegener and continental drift which led to plate tectonics –
a really concrete example of a theory changing because scientists found the evidence of what drove
the whole process. Then I wanted students to look at other examples (from agriculture, chemistry,
biology and physics as well as earth science) of scientific theories which have changed over time.
I chose to use a hands-on type of assessment, which I believe is more appropriate for NoS. I also
decided to experiment with a group assessment. And I wanted to incorporate both the Tricky Tracks
(which linked back to fossils) and Tangram activities for this.
So this is the teaching sequence that developed:
Scientific theories and evidence
Specific Learning Outcomes:
By the end of this unit students will
 Understand that science is based on interpretation of evidence
 Understand that as new evidence is uncovered explanations change
Lesson 1: Fossils provide evidence
Learning Intention – To understand how fossils can provide evidence
 “Use the sheet What do we Know About Fossils? (Appendix A) to stimulate thought to answer
the question: What do we know about fossils?”
o Think – pair – share  build a spider diagram on the board
 Discuss:
o “Who has seen or held a fossil? Tell us more.”
o “Where can we find fossils in Auckland?”
 “These fossils can give us information. In fact they can provide evidence.”
 Discuss – “What do we mean by evidence? Where do we use it”
o Come to some consensus of scientific evidence being:
 Information accumulated through observations (of the natural world or during
experiments)
 to support or reject a hypothesis (compared with law, where the purpose of
evidence is to find the truth)
 collected systematically to avoid the bias inherent in anecdotal evidence
o Ask students to write a definition of scientific evidence
o “What might fossil evidence tell us?”
http://www.ucmp.berkeley.edu/education/explorations/tours/stories/middle/C5.html
images about evidence from fossils – only needed if students have minimal
understanding.
 Goya activity (Appendix B), students use the evidence of a fossil to decide what the animal ate
and identify a descendent.
 http://www.sciencelearn.org.nz/Contexts/Dating-the-Past/Sci-Media/Video/Peat-cores-andclimate-change A video clip about evidence from NZ geology – what NZ fossils can tell us about
climate change. To be used if there is time
 Students fill in a reflective journal – what did they learn today?
Hwk: Ask parents/older family members how some ideas have changed during their lifetime and
discuss reasons why they changed.
Lesson 2: Continental Drift
Learning Intention – To understand Wegener’s theory, the evidence and the gaps
 Discuss hwk findings – “what sorts of things have changed?”
o “What does this tell us about our world? About science?”
 Review yesterday’s lesson (Do Now): Students to record 3 ways in which fossils can provide
evidence.
 “We are going to explore a geology theory that has changed over time with the activity Historical
Overview of Wegener (Appendix C -1)
o Read info on Wegener as a group –
 Check understanding of key terms: continent, meteorologist, proposes
o Process this info – by writing speech bubbles to represent different perspectives (sheet is
Appendix C-2, but only use 1st 3 cartoons for this activity)
o Walk & gawk  Discuss what you read in others’ bubbles.
 Discuss as a group:
o Why was the shape of the coastlines of Africa and South America not enough to show the
continents had been joined?
o What is the significance of the rock and fossil evidence?
o “What were some reasons why Wegener’s ideas were not accepted?“ Along with
scientific reasons, include the idea of nationality and timing (a German in 1915) being
factors
 Students fill in a reflective journal – what did they learn today?
Hwk: Find some science ideas that have changed over time (2 nights for this).
Lesson 3: Plate Tectonics
Learning Intention – To see how the theory of plate tectonics developed
 Discuss hwk – this will continue tonight too.
o “What sorts of ideas are you finding out about?”
o “Which scientists feature?”
o “What search terms helped you find info on the Internet?”
 Review yesterday’s lesson (Do Now): Students to discuss with a partner - What was Wegener’s
theory? Why was it not accepted?
 “As technology developed the evidence started to point to the surface of the crust being
fractured into several plates.”
 Ask pairs of students to reassemble the jigsaw of tectonic plates (activity Appendix D-1). Then
discuss
o “How good is the fit?”
o “Where are the boundaries mostly?”
o “Where is NZ wrt these boundaries?”
 “So lets look at the evidence”
 Form students into groups of 3. Each student to take a special role – oceanographer,
seismologist or vulcanologist (this is their home group). Then ask all the students to form a
different group with others of the same specialty. Each is given their specialist research oceanography, vulcanology, or seismology - with information about the evidence from their
specialty that relates to plate tectonic theory (appendix D3 to D-5), and a copy of the blank plate
tectonic jigsaw puzzle (appendix D-2).
 Each specialty group transfers across to their blank plate tectonic map the research evidence
from their specialist research group, and discusses the questions on their sheet.
 Then all students return to their home group and share their findings till each student has all 3
lots of info on their blank map.
 Discuss:
o “Which pieces of evidence suggest tectonic plates form?”
o “Which pieces of evidence suggest tectonic plates collide?”
o “How does the theory of plate tectonics explain what your specialty research information
has shown?”
o Can this theory of plate tectonics explain all of the pieces of evidence we investigated?
o “Why did Wegener not have this information?”
o “Was Wegener / continental drift wrong?”
o “How does plate tectonics relate to us in NZ?”
o “How might we use plate tectonics to explain the big Christchurch earthquakes?”
o “Where do the Auckland volcanoes fit into this picture?”
o “Why do you think scientists form collaborative teams instead of working alone?”
 Students write a paragraph about the theory of plate tectonics (summarises the key learning for
the day so no reflective journal today)
o “What are some science words we should include in this?” Write them on the board
before they start their writing.
 Hwk reminder: You may have found several examples of science ideas that have changed over
time. Be prepared to speak about one of them tomorrow.
Lesson 4 & 5: Changing Science Understandings
Learning Intention: To understand scientific theories change over time
 Discuss Hwk:
- “What have you found out about science ideas that changed over time?”
- “Examples?”
- “Any patterns that you see?” (no teacher comment for now)
 Review yesterday’s lesson (Do Now): Students to record - What is the theory of Plate Tectonics?
What was the evidence for it?
 “We are going to look at some other science ideas that have changed over time.”
 Use activity: How science ideas have changed over time (Appendix E). 3 different tasks:
-



Match 3 theories with the evidence that overturned/changed it
Match 3 theories with their author and the date
Students choose one old theory from a list of 5 and find out some specific info, working
as a team, with access to books and internet (may take 1.5 periods). Then present their
findings to the class. Teacher needs to go through the roles with them carefully before
they start.
- Students record a sentence or two about each one during presentations
Discuss –
- “What are the patterns/similarities?”
- “Why do scientific theories change?”
- “Why is it important for us to know that science ideas change with new evidence?”
Students to write a sentence or two about why scientific theories change with a couple of
examples.
Students fill in reflective journal - what did they learn today? Ask them to include a comment
about their role in the group and how the group work went.
Lesson 5 (2nd half): What Have we Learnt?
Learning Intention: To assess the learning from this sequence of lessons
 Tricky tracks (Appendix F-1) – the first picture is put up on screen.
o In their groups students decide:
 “What can you see?”
 “Why were the animals heading to the same spot?”
o Now put up the second picture. The small group discusses:
 “What can you see?”
 “Why might this be happening?”
o Put the third picture up on the screen. The small group discusses:
 “What do you see?”
 “Why might this be happening?”
 “Based on the same set of evidence you may have several different theories of
what happened.”
 “Did your theory change between the 1st and the third picture?”
 “If so, how did it change?”
 If you didn’t change, why not?”
 What is the place of evidence and fossils and theory in this activity?
o General discussion
 What explanations did you find? What evidence suggested that?
 How did being in a group help in this activity?
o Students glue in the picture and record 3 different explanations
 Tangram (Appendix F) – as a group, students fit pieces together, then are given the extra bit and
fit them together again in a different configuration. Then each student to answer by themselves:
o How is this activity like what we have found out about evidence and theory?
o Give 3 real-life examples of these ideas?