1. During a hands-on investigation of minerals, students were asked to calculate the density of a set of minerals. Students graphed the set of minerals according to the density of each, and then answered questions that required them to use their graph along with information about other properties of each mineral. They key question was, “Is the density of a mineral related to its chemical composition? Are other mineral properties related to density?”

2. Students created a data table in Excel of minerals and their densities and then made a graph of this data. They answered follow-up questions based on the graph and a table of information about the minerals.

3. As was mentioned in a previous discussion, the data that students collect is not always very accurate. I still had the students collect their own data and pass it in, but the final data set we used was one that I put together. I didn’t want to spend the time doing this activity if they couldn’t draw any conclusions (or draw incorrect ones!) from their results. I think the students were more engaged knowing that the data they were using had been gathered by the class; it gave them some sense of ownership and tied the activity into other things we had done in class. (What they don’t know won’t hurt them – right?)
As students were working on this activity, I realized that many of them didn’t really know what to do with their graph once they had finished making it. I tried to include questions with the activity that would force them to use the data; of course some students did, but some did not. We’ve done a few more graph analysis activities since this first one and I think they are catching on! For many students, this was their first exposure to Excel, so they were introduced to making a data table, naming axes, labeling the axes, formatting the graph, etc. Some students were already proficient in Excel and I asked these students to help out others who had questions.

4. In the future, I will ask students to compare the use of data from a table versus a graph. I want to emphasize that it is the same information, but there are benefits to representing the data in a graph. I will also include more questions about the analysis of the data, to give students more practice.

Hi Becky, I am pleased to see that you found a creative way to integrate DATATOOLS into a mineral unit! Very clever. I like what you had your students do and I also stuggle with students both owning the data and having accurate data to help develop some concept. Sometimes I feel that maybe I should just do one or the other, but I like your solution here and have done it a few times. Maybe this is a reason in favor of the debate on the use of interpreting data sets rather than having students try to do both.
As far as analysis questions, what kind of patterns/explantions were they coming up with and is that what you were hoping for? I would think that their might be a connection with the chemical composition of the mineral, perhaps calculating formula weights for the minerals and seeing if their densities support those calculations.

Hi Becky,

I love your question about the relationship between chemical composition and density. That question should challenge the bright children. How many students were able to answer that well? Considering Chemistry is touched upon in a very elementary way in middle school, I am eager to know the outcome. Mitchelle has also done a similar lesson where the children compare the densities of various objects with that of water. Anyway, by using datatools for charting you have made children focus on 'density' and other related science concepts rather than calulations alone.

The comment on accurate data rings a bell. But sometimes I am actually hoping that we have some inacurate data in the data set.

Fo example I do a lab where we count the number of drops of water you can place on the head of a penny and the number of drops of water you can place on the tail of the same penny. The point of the lab is to see if using statitics can provide us with the answer to the age old questions "which holds more water the head or the tail of a penny" (By the way I don't think there is a statistically signficant difference.)

One of the things that happens a lot with this lab is that students get competetive and see who can get the MOST drops on a penny. (which has no bearing on the question we are studying actually.) They sometimes get so competetive they get "creative" with the answers they come up with - 80 - 90 drops of water....

Now this lets me open up a discussion of looking at data sets for anomolies and out liers and how different kinds of stats are more or less sensitive to them.

Now this only works if the majority of the data is useful I don't know what I would do if half the class decided to fudge their results, but that has never come up.

Z-YA

Jayanthi and Mark,

You asked similar questions about the analysis of the data. Most students were able to conclude that the most dense mineral, galena, was probably so dense because it contains lead. They could also see that the minerals at the top of the list all had dense metals in them, mostly iron.
But, when I asked them to compare density and hardness, most students didn't look at the data at all and just wrote that the dense minerals were all hard. When working one-on-one with some students, though, they did look at the data and saw that it didn't fit their first assumption, but they weren't confident enough to write, "No, there isn't a clear relationship." It was kind of a trick question, but I wanted them to see that no can be an acceptable answer if their data supports that.