10. Teaching to Promote the Development of Scientific Knowledge and Reasoning About Light at the Elementary School Level

        While children are naturally curious in the way they investigate things, this does not mean they are scientific.  It can, however, be built upon to help teach them scientific ideas.  There is evidence students can develop the right framework even at early ages.  There is no unanimity as to the sequence of topics that should be taught in science; what is foundational for later science is what it means to engage in scientific inquiry.  This can be accomplished through many different topics.   Light is a practical topic that can be investigated with regular tools.  It is also a good topic because it conceptualizing it differs from our experience of it.  For example, light travels, yet we do not see it travel.  Thus the study of light requires a conceptual change.  Shadows, too, provide conceptions that are very powerful to explore in this context.  

Conceptual Understanding

        Some salient concepts for science include standards for communicating ideas, patterns in observation stated as knowledge claims, use of evidence to judge, hypotheses, claims being subject to challenge.  
        Salient concepts for light include that all objects reflect and absorb light, and some transmit it; there is an inverse relationship between reflected and absorbed light; what we see is light reflected from objects; a shadow is formed when an object blocks light; the color of an object is the color of light reflected by it.  

Prior Knowledge

        Some common beliefs are that shadows are objects and that light reflects only from shiny objects, that light travels (which we can't see), that is applies pressure (that we can't feel), that dark is when none of the colors are reflected, and that light can be described as a particle or a wave.  As daily experience reinforces ideas quite different then some of these, part of the approach is to have students test out their preconceptions.  


        Having students question their own assumptions is an entirely new way of teaching science.  For example, if a student thinks that only shiny object reflect light, they should challenge themselves to find evidence that other objects reflect light too.


        Having students observe phenomena is important to an inquiry approach because it may lead to discrepant observations that challenge their understandings, and it also gives them experience with the norms of scientific observation.  As inquiry is very time intensive, both 1st hand and 2nd hand experiences are built into the curriculum - the 2nd hand experiences being a fictitious notebook of a scientist who is testing out ideas.  

A Heuristic for Teaching and Learning Science Through Guided Inquiry

        A Heuristic showing a cycle for investigation (engaging, preparing to investigate, investigating, preparing to report, reporting) guided the inquiry.  
In the engage phase, students begin by asking questions such as what do I know, what do I want to learn, and what have I learned (KWL).  When students make claims about knowing something, teachers could ask about the nature of the inquiry used to reach that conclusion, which is a hallmark of skeptical science.  Next, the class can talk about the tools used to investigate.  From here, students should have developed questions which the teacher can further refine.  
        In the preparing to investigate phase, students need to figure out how they will investigate their question.  The teacher may provide information about procedures to use or students may invent them themselves.  Nevertheless, teachers must investigate why particular approaches and procedures are useful.  For example, they may ask the students to explain the advantages of using a particular tool.  During investigation, the teacher should periodically reassess students' understanding.  A critical part is also figuring out how the students will record their observations.  In group work, having roles can be helpful.  Modeling and role playing such roles can be useful in preparation too.  
        As part of the investigation, students document their observations.  The teachers role is to monitor them and attend to the conceptual ideas.  It is very important for the teacher to continually inquire and guide the students, particularly for the more complex tasks.  
        In the prepare-to-report phase, students prepare presentations for their classmates.  Focus becomes on convergent, instead of divergent, thinking.  Students can create posters to make claims, supported by their evidence.  Teachers can encourage students to draw and write their presentations.  Feedback process, which can take many forms, is important to sharpen the students' work. 
        The report phase includes the actual presentations.  It is complex and rich with opportunities for the teacher to engage in supporting students' thinking and actions.  Ultimately the class must decide about the legitimacy of the claims.  Oftentimes there are contradictions, which leads to questions about how to further investigate.  Oftentimes, students do not want to accept true physical claims, in which case they must be dealt with through further questioning of the scientific process (how can we provide more evidence? what would be convincing?) or other methods.  

Second-Hand Investigation

        As suggested by the National Science Education Standards, science instruction can also include learning from text-based sources.  These can focus students' attention on the core concepts.  The question is how to keep them actively engaged.  To do this, this unit created a fictitious notebook where the "researcher" thinks aloud.  The teacher started by giving the students an overview that included identifying the parts that made it a notebook.  There was also comparisons of the students' claims and those in the notebook.  One key aspect of making this notebook work was having the students take a skeptical approach to it.  


        Students can never understand all the concepts the first time through a unit.  Therefore, there needs to be cycles of investigation to allow them to "pick up" the concepts they didn't get the first time around.  These should be in different contexts.  

The Development of Conceptual Frameworks

        The common thread among all the cycles must be made explicit in a conceptual framework for deep understanding to occur.  This has been the critical factor in determining successful school reform efforts.  In four cycles in Ms. Lacey's class, after each cycle a concept map was produced to show the classes' knowledge on the subject.  This map was refined after each cycle until a clear one was developed by the end.  


        It is important that teachers know the concepts well so that when a students makes a poor claim, the teacher's uncertainty does not hamper effective decision making.  Furthermore, the teacher must also know what observations may convince a student to change their mind.  This is called pedagogical-content knowledge.  The more teachers understand about how their students think about a concept, how that thinking might unfold, and how they may ascertain the students' thinking at any moment - the better they can get their students to achieve the desired understanding.  


        Science instruction provides a rich context for the principles of How People Learn.  Teachers need quite a deep level of understanding to apply this well, so that students are not just learning knowledge, but understanding the nature of inquiry.  A heuristic was proposed in this chapter to guide this process, as well as how 1st and 2nd hand accounts can be used in the classroom.   

See Think Wonder
  • What do you see? (Looking at the heuristic for guided inquiry)
I see a cycle with arrows.  There are four areas as part of the cycle, and one without.  The four within have two rings - outer and inner.  The one concept that is not part of the cycle both feeds the cycle but also accepts feedback from one part of it.  First, I start with a question (eg. What is gravity?).  Next, I prepare to investigate.  I create methods and test explanation.  Next, I investigate, recording my observations.  Next, I prepare to report.  I identify my theories and conclusions, as well as my claims and evidence.  Then, I report first to a small group, then to the entire classroom for evaluation.  From here, either I re-engage with a question, or I find empirical relationships and new explanations that I must further investigate to solve the same question.  If that is the case, I must restart the cycle. 
  • What do you think about that?
I think this is a very systematic way of inquiring about a subject.  It is quite general, however, and without some practice or specific examples (which are given in the chapter) it could be hard to understand.  I do think it is a good model to get students to conduct their own experiments and make there own conclusion with the accountability to others (to make sure they are making sense).   
  • What does it make you wonder?
How can I apply this to other topics within science?  How often must you refer to it in the classroom explicitly, or should you just let it guide you, the teacher, as you plan.