Saturday, March 3, 2012

Reflections — Fossils 2

In 2010, I was nominated for the Presidential Award for Excellence in Math and Science Teaching—a prestigious honor for math and science teachers in the United States. The rigorous application process provided me with an excellent opportunity to reflect deeply on my classroom practice. Although I was not selected as a finalist, I value my experience in the process. Over the next three blog posts, I would like to share some of what I wrote for my application, which centered around a geologic unit on fossils.

The PAEMST application requires a written narrative on several dimensions of outstanding teaching, including the following areas:

  • Dimension 1: Mastery of Science Content
  • Dimension 2: Instructional Methods and Strategies
  • Dimension 3: Effective Use of Student Assessments

In this entry, I would like to share Dimension 2, Instructional Methods and Strategies...

I employ a variety of instructional approaches to help students understand fossils...

Rock cycle video and diagram
Students watch a locally-produced video about the Rock Cycle, which identifies the three main rock families, explains how they were formed, and shows many local examples from each family. Students collaborate after the video to complete a blank rock cycle diagram with terms about rock products and the geologic processes that created them.

Rock identification lab
Students engage in a hands-on process of rock identification to learn the various physical properties and characteristics involved in identifying rocks by family and name. As part of the identification process, students must provide convincing evidence to go along with their identification.

Law of Superposition activity
Students infer the relative ages of rock layers in a vertical rock profile by examining and discussing various clues. They discover that, in general, the oldest rocks and rock layers are at the bottom of a rock profile—the Law of Superposition.

Traces of Tracks activity
Students analyze an image of fossilized animal tracks and reconstruct the story of an encounter between predator and prey. Students collaborate to infer the story from the trace fossil evidence.

Finding Clues to Rock Layers activity
Students analyze fossil clues and data contained in rock layers to determine the relative ages of the layers as well as the physical environment in which the organisms lived. In general, the deeper the rock layer the older the fossils buried within. Additionally, various geologic processes, such as weathering and erosion, can expose fossil layers at the Earth’s surface. 

Fossil ID Cards
Over the course of several days, students “interview” various fossils to infer the life story of once-living, but now fossilized, organisms, and create a detailed fossil identification card for each fossil interviewed. This hands-on, inquiry-based lab allows students to fully engage in the process of science by observing fossil specimens; asking key questions; gathering evidence from physical clues and inference; using a variety of scientific resources such as fossil identification books, posters, and diagrams; learning to avoid bias by following the fossil evidence; sharing data and ideas through peer collaboration; and hypothesizing and theorizing about the past geologic environments in which the fossil lived. Students display their fossil cards on large posters for the rest of the school to enjoy. 

Examples of interview questions include:

  • What are the fossil’s physical characteristics? 
  • How did this fossil move? 
  • What did it eat? 
  • In what environment or habitat did this fossil live? 
  • What was its niche or purpose in life?

I identify and build on students’ prior knowledge, and incorporate this knowledge in my general teaching strategies...

Image courtesy of MorgueFile
I strive to ensure that my science lessons build logically from point A to point B and that common themes and ideas are continuously woven throughout each unit as well as throughout the school year. My goal is to promote the transfer of understanding from one lesson to another, not just one-time memorization to be forgotten quickly. I regularly ask discussion questions that help activate prior knowledge, that tie different lessons together, and that help students make logical interconnections among various ideas and concepts.
  • “Does anybody have a fossil collection? Tell us a little bit about your fossils.”
  • “Have you ever been to a museum and seen a fossil dinosaur on display? Where did all those bones come from?”
  • “Remember when we watched the rock cycle video? In which rock family would you most likely expect to find fossils? Why?”
  • “You can find fossil sea shells up in the Rocky Mountains. How can that be? What do these fossils tell us about Earth history?”
  • “Suppose you find a fossil of an X. What story can this fossil tell you? What are some clues you can look for to help explain this organism’s life?”
  • “Here is an example fossil. What characteristics do you see? What kind of organism was this? What did it eat? Where did it live? How do you know?”
In the video I produced for my application, I used many of the types of questions outlined above to help students learn how to interview fossils in order to uncover their life story. My goal was for students to develop a non-biased technique for uncovering clues and evidence contained in fossils. For our fossil lessons, it is most important that students learn to “listen” to the fossil evidence with an open mind rather than just try to quickly name the fossil.

The video shows the first day of our fossil lessons, where we worked together as a group to prepare for our in-depth fossil interviews. The following three days after the video, students interviewed fossils, gathered information and evidence from the fossils and various classroom resources, and created detailed fossil identification cards with the inferred life story of each fossil.

I use instructional strategies and techniques to meet the learning needs of all students, challenging those with stronger knowledge while ensuring learning for less accomplished students...

I utilize a variety of strategies to differentiate for the diverse learning needs of my students, and a few of these are outlined below:
  • Creating hands-on, inquiry-based, authentic learning experiences that encourage students to think critically and develop explanations based on evidence
  • Encouraging peer collaboration: students working together, talking science together, sharing data and ideas together
  • Accommodating for different fossil identification skill levels: 
  • Inferring basic to advanced information from fossil clues at increasing levels of descriptive detail
  • Interpreting fossil structures from simple (bones, teeth, shells) to complex (type of bone, purpose of tooth)
  • Working with incomplete vs. complete fossils (incomplete fossils are much more challenging to interpret than complete fossils)
  • Drawing upon multiple intelligences skills and multiple learning modalities: drawing/visualization, writing, questioning, spatial manipulation, kinesthetic/hands-on observations
  • Using effective questioning: engaging students (individually and within small lab table groups) with highly effective questions to encourage deeper meaning


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