Search 
Monday, September 6th, 2010   
  

  





Main Menu  

  
Sign Up for our Email Newletter!

* required

*







  
http://www.acadiapartner.org/index.php?module=ContentExpress&func=display&ceid=32

Latest Blog Entries  

  

Students and Graphs

Tuesday, February 02, 2010


 

Teachers at Saturday workshopThe "Acadia Learning" program is the outreach program at SERC that works with teachers across Maine to engage them and their students in science that is connected to research here at the park and at the Mitchell Center for Environmental and Watershed Research, our partner organization at the University of Maine.

This past weekend we conducted a workshop with teachers from Scarborough, Old Town, Mt. View, and Nokomis high schools to introduce some new thinking we have done in the area of helping students work with graphs.  Graphs are important because they are a way for students to express their understanding of what is going on in the streams, forests, and fields that they study. They are also a tool that teachers can use to see how students use data that they collect to develop that understanding.

Over the past three years of looking at students' graphs and poster presentations as part of the Acadia Learning project, we have observed that many students seem confused about how to express their findings on a graph.  The problems go beyond simple graph mechanics -- titles, labels, and the like.  A lot of graphs just don't seem to make sense in ways that we would expect.  So, over the past year we developed the first version of a written diagnostic tool to probe student understanding, and misunderstanding, of how to organize and present their findings.  The workshop this past weekend introduced teachers to the tool and engaged them in a day-long discussion about students, graphs, and data.

Many kids have real difficulty in making sense out of data.  This is true even when the data are pretty simple.  The difficulty comes in an interesting place:  the kids appear to have trouble thinking in terms of groups of things.

For example, on our written test we gave students some data on the abundance of dragonfly larvae in two streams.  The data consisted of a count of dragonflies found in each of ten samples, identified as samples "A" through "J," taken from the streams.  One stream had a rocky bottom; one had a mucky bottom.  We asked the students to "draw one graph showing the data in a way that helps you figure out if the type of stream bottom has to do with dragonfly abundance (number of dragonflies)."  What we were expecting to see was something that summarizes the results for each stream, comparing them in a graph something like this:

student graph of dragonfly data - expected result

However, what we got back from most students was a graph that looks more like this:

student graph of dragonfly data

In this graph each bar is the number of dragonflies found in each sample.  What is missing is an answer to the question of how the streams differ.  Most of the students responded in a similar way, dealing well with the individual data but -- for some reason -- failing to go beyond the data to create a generalization that answers the question that we asked.

Each of these students knows how to compute an average and probably would have done so had we asked for a comparison of the "average number of dragonflies" in each stream.  But we didn't tell them how to answer the question.  We just asked them to figure out the relationship between stream bottom and dragonfly abundance.  Given that question, and a set of data related to it, most students had difficulty connecting the data and the question.

We are concerned about this dificulty because science literacy involves being able to make useful generalizations on the basis of observed data.  Even more fundamentally, science literacy requires understanding how science works -- what it is. 

Last year we asked several hundred high school students some questions to get at this central notion: Just what is science?  For the most part, their notion of scientific discovery was much like the discovery of a new island or of a lost continent.  You look (using something called "The Scientific Method") and, if you keep looking, you find things.  Sort of like finding a lost sock.  The "discovery" was there all the time, waiting to be uncovered.  I suppose this notion might come from common perceptions of things like discovering a new miracle drug.  It was really there.  It is a fact and was always a fact.  It just took a scientist to "discover" it.

What was largely missing from the students' view of science was an understanding that science is constructed.  The discovery of a new drug builds on generalizations -- theories -- constructed over years by chemists, biologists, pharmacologists, and others.  More simply, the only way that you can begin to say anything about dragonfly abundance in two streams is to move beyond observed phenomena.  You need to be able to construct an aggregation of some kind, abstracted from all the individual observations.

It is not just the idea of using an average in place of all the individual observations that gives kids difficulty.  When we show them a set of data showing a relationship between two things, they have difficulty seeing the general relationship if there are couple of data points that don't quite fit.  Or, when comparing groups, they tend to make decisions on the largest or smallest values, rather than seeing the data as a group. The tendency to focus on phenomena, rather than on patterns and on generalizations supported by the data, shows up in many places.

Here's the problem:  we would like to work with students to get them to understand concepts such as the mercury cycle, food chains, or ecological balance.  And they do learn about these things and can talk about them, as concepts.  But when we send them into the field to put these concepts to use, collecting data and thinking about what their data might mean, they get stuck.  They have great difficulty finding meaning in the data, connecting what they observe to the bigger ideas.

A lot could be written -- and probably should be written -- about the danger of having powerful ideas that are not rooted in facts, or of having a lot of facts uninformed by insight.  Here I will simply say that it is at the heart of what science teachers try to help students learn to do.

The teachers who participated in our workshop this past weekend went away armed with the first, test version of the diagnostic tool that we developed and with classroom activities that we hope will help students make connections between things that they count and measure and the bigger concepts that we want them to think about and understand.  Over the coming months we will get some first-level evidence about how well this works and about how we might improve it.

This educational research grows directly out of the work we have been doing for the past several years, exploring ways to engage teachers and students in research.  That work has uncovered new problems and challenges, and we have extended our educational research and developed new professional development and curriculum materials in response to what we have learned.  In many ways, this is just another step along that path. 

But in other ways, this feels like engagement with issues that are somehow more general and fundamental. The ability to keep a question in mind as one looks at data, and to then use those data to shed light on the question, is at the heart of our use of science.  This is not know-how needed only by scientists, but also a capability that citizens need as they work to understand issues related to resource use and conservation.  We will keep you posted as we continue to work with teachers across Maine to understand what students are doing and to assist them in leading students toward new capabilities.

-- Bill Zoellick


  

Mission Contact Facility Reports and Articles