Questions for Wed:These are some questions regarding density that could go on the blog.
1. Did the true value for density fall within the confidence interval? What is the significance of the confidence interval with respect your experimentally measured density and the true value of density? No. Our average density was 5.5 g/mL. Zinc's true density is 7.1 g/mL. We originally followed the protocol and used more than one balance. After determining that one of our values was substantially different than the others, we went back and used one balance for all of our masses. Had we chosen the other balance, our results would may have fallen into the confidence interval. Using the calculations, the 95% interval was 5.08 g/mL-5.92 g/mL.
2. Does the interval increase or decrease and as the confidence level changes from 90 to 95 to 99% and is the change intuitive? Could you explain the change to your students conceptually?
The interval increases as the the confidence level goes from 90 to 95. I would use an analogy to explain it to students. If a finite (e.g 100) amount of raffle tickets were available for purchase and you wanted to guarantee yourself a 90% chance to win, you would need to purchase 90 tickets. If you wanted to guarantee an even higher percentage of success (success being the likelihood that you would win) you would buy more than 90 tickets - giving yourself a larger number of opportunities (larger interval) to win.
3. The procedure for measuring density for the liquid used a graphical approach as opposed to our three trials and average method for determining the density of the solid. If you made a determinant (human) error for your first measurement in the liquid density portion, would this error plague or affect the subsequent measurements? (try to think of a situation where it would not and a situation where it would). If you were using cumulative measurements, it should only affect the first measurements. If you were going back and subtracting the starting measurement from each subsequent measurement, it would have a greater effect because the the error would be repeated several times. If the error was not in the measurement of the unknown volume, but was instead an error in measuring the mass of the beaker and parafin, that error would be repeated throughout the experiment.
4. Look at the plot for light intensity, again. Look at this expression of yesterday's question: Can you think of any light sources that might not give a inverse square law drop off? Also,determine the power output of your bulb in the light lab. We determined the power output to be 67mW.
5. Discuss the tech tools you are using (blog, google docs, excel, lab quests and probes) and how you might use them (or not) in your teaching? Why?I have been thinking about this quite a bit the last few days. The lab quests and probes are not something that I would generally use in my current teaching situation. I could see that they could be valuable tools, however.
As for the blog, I can definitely see some opportunities for teaching. I think the blog could serve not only as an "assignment notebook" of sorts, but it is also a great tool for communication. It would allow students to provide nearly instant feedback about a lecture or an assignment. It would be a great tool for formative assessment as students might feel more comfortable sharing struggles in the form of a blog than they might feel about asking a question in class.
Google docs has many potential benefits as well. While we did have some trouble sharing Excel workbooks with graphs, I could see that this could be a great storehouse for information. It would allow teachers to share with students and vice versa. It could also be a great place for colleagues to share helpful teaching tools. I could see that administrators might be willing to let us use it to collaborate more between disciplines.
I still need to work with Excel to unlock some more of its capabilities. I have no doubt that it is capable of far more than I could ever think to use it for. I do feel like I have learned quite a bit about the mathematical value of the graphs that we have practiced in just the 2 days we have had so far.