An Introduction to Field Data Collection - Part 1
John Nevins Crandon High School Crandon, Wisconsin
The goals of this activity include:
Be sure to exercise caution if you use ceiling tiles. We used lab tables as a mode of access to the ceiling. Alternatively, ask the custodians if they have some damaged tiles.
Engagement and Exploration (Student Inquiry Activity
My students do not have an understanding of how a scientist would go about studying a large area. They are concerned about things like global warming or the ozone hole, mainly as a result of news coverage, but they have no idea of how the researchers gather the data and use the data to reach conclusions. As a result, they are not well equipped to judge whether information of the sort used for survey results, population studies and many other forms of data acquired by researchers produces valid information.
This activity helps to illustrate how scientists collect data from a large area (28,000 sq. km) and use sampling methods to make a judgment of conditions over a wide area while limiting the number of individual field measurements to a practical number. I sometimes like to think of this as counting the uncountable. What is an appropriate method for collecing a sample? How are the data extrapolated? How many samples are needed to be representative?
This parcticular activity is an outgrowth of one of those “Teachable Moments” that sometimes come along by accident. I was trying to explain the process used by many of their parents when they bid on timber harvesting (we live in the “North Woods” of Wisconsin and quite a few people make a living supplying wood products) and some of my students had their attention else where. I had one of those memories of watching the ceiling and wondering how many holes were in the acoustical tiles. The idea immediately sparked some interest and laughter so I decided to try to find out.
Elaboration (Polar Applications)
(An interesting thing happened the first time I tried this one. Our superintendent came through with a board member and several guests on a tour of the department just in time to see my students on stools and lab tables counting the holes in the ceiling. It’s a good thing they are not easily shocked by me. In fact, they acted like nothing unusual was happening in my class.)
When the students complete their counts along the transect, have them post their results on the board so that all the students can copy the results. Then go through a sample analysis with a part of the data. In that analysis they should calculate the average number of holes in a square meter and multiplied that value by the area of the ceiling.
(Another bit of information that can be figured out from the data is the number of lights in the room based upon how often the count was zero. When this is done it has poorer results with individual transects than it does with the whole data set from the class. This can help illustrate the degree of accuracy that can be achieved with this method.)
For example data and calculations see below.(insert table here)
Evaluation (Assessing Student Performance)