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[dr_strangelove]

On preview, g_h is essentially correct, about acceleration and braking. Again, for braking, it is the frictional force between the road and your tires that actually slows you down.

Are Conjugate and I being confused again?  That's physics professor crazy talk!

And it looks like Boethius figured it out.

No, Dr. Strangelove is the one being confused.  Each of us knows who we are. 

Sadly, I'm never confused for anyone, I'm just confused.

[barcrossliar]

Just thought I'd weigh in, I mean add my mass, I mean put in my two cents of equal mass.

If we didn't teach anything until we could teach it with complete accuracy, we'd never teach anything.  We want our students to start teaching science before kindergarten.  We want them to keep teaching the  same basic concepts, but with greater detail and complexity as the years go by.

I'm with Poly here.  My elementary ed students have enough trouble with "mass is stuff and volume is how much space it takes up."  If they understand that and other basic concepts well enough to teach confidently, using inquiry and other effective methods, we've got generations of elementary school kids who will have a good background and interest in science who can learn more about it in college.

On the other hand, if we try to teach elementary ed students way more than they're prepared to learn, we get students who are so confused and intimidated by science that they avoid teaching it or will only read the book aloud.  We then have generations of science-phobic, ignorant students who will avoid science in college.

In a perfect world, science experts would want to teach in schools, and elementary ed students would be great scientists.  I don't live in that world.

[astrofraa]

Thank you, polly_mer, for your in depth and very helpful explanation.  I was quite sincere when I asked why "amount of stuff" worked better for you, and you have convinced me.  In fact, when you pointed out that students rolling on chairs would get them to mix up friction, velocity, and those other concepts, it's made me wonder whether my students last semester really got the point there that I thought they did!  :-)  We're going to get into mechanics in a week or two -- I'll find out!  I'm in my fifth TT year, and I have only taught non-major mechanics once (and a long time ago, to boot). 

The penny lab sounds great!  I may try that next year myself.  I save a big bucket of pennies for them to use as a physical model for radioactive decay; this would give me another use for them!  Thanks!

Yours sincerely,

Astrofraa

[polly_mer]

You're welcome, Astrofraa.  Teaching this physical science for teachers course (in addition to physics, we also cover intros to chemistry, astronomy, and earth science) last semester was an eye-opening experience since I did all of my education at schools set up primarily for STEM students.  The realization that most of my students had never thought about the phenomenon at hand (whatever it is), would not take two minutes to think about it when asked a direct question and given the opportunity to use equipment to try things out, and then tell me that it doesn't matter because no one uses it anyway just blew me away.  Consequently, I had to learn the hard way that everything has to start from the connections to their daily lives because they often discount whatever we do in lab or class as fake and mere examples of that "crazy science professor thinking" to modify Dr_Strangelove's phrase.

I can understand not being particularly interested in a given unit (myself, I'm not terribly interested in electricity and magnetism, but we still do a unit on it because it's important for these students to learn that material and I can get excited about it for that short length of time), but the idea that none of the material matters in daily life or even as something to teach their students just so that they get adequate job performance ratings just stuns me. 

To take a turn in direction, if anyone has any ideas about how to get my seriously math-phobic students to really get the hang of graphs in short order, I'm all ears.  My students are slightly more on track with that than G_H's.  I told them to slap a line of best fit through the data and they did.  Then, in the slots for the recording of two points on that line, they promptly recorded two random data points from the original data set with no regard for whether those points were on the line, in spite of my explicit instructions about how to select points that lay on the line and were at the intersection of the grid so that one could easily read them off the plot.

[anakin]

To take a turn in direction, if anyone has any ideas about how to get my seriously math-phobic students to really get the hang of graphs in short order, I'm all ears.  My students are slightly more on track with that than G_H's.  I told them to slap a line of best fit through the data and they did.  Then, in the slots for the recording of two points on that line, they promptly recorded two random data points from the original data set with no regard for whether those points were on the line, in spite of my explicit instructions about how to select points that lay on the line and were at the intersection of the grid so that one could easily read them off the plot.

I may be able to offer some help. I discovered that when I show students how to represent their hypothesis (its resulting predictions) on a graph, they thought that was the neatest thing ever. I get them to practice by coming up with goofy outrageous (therefore low-stakes, medium-humor, and high-retention) hypotheses - as the planet continues to warm, there will be more pirates. Then suppose we collect a bunch of data. I then plot a very "accurate" graph of data points through year 2000 with significant variation about what will become the line of best fit. Now, class, what do we want to be able to do with our results and graphs and such? Someone figures out it's 2010 and we want to predict number of pirates today. But how, how? Yes, we need a line! I eyeball it and draw it against a meter-stick. Then I ask how many pirates there were in 1880 (data point significantly above our line). They respond with the accurate number. "But why not Y?" (y-intercept of the LBF) I ask. Duh, they say, that's the line, not the data.

As I'm thinking about my process - this is good for me to do, helps me figure out why these things work. I'm thinking that connection with "real" data from tangible systems (everyone can visualize a pirate, and everyone's heard of global warming), and me asking them what to do next instead of telling, increases comprehension and retention. Also when I ask, I find out what they don't know that could interfere with their learning, and I get to deal with it right then.

[luvstowrite]

If I can add my two cents, I approach teaching science education with the view that it's all about looking at data and making decisions from what the data shows. We might consider historical data with our current data.

Why do/does (insert profession or industry here) do what they do? What are their options? How do they test new products (i.e., drugs) or procedures (i.e., harvest methods) against other new products or industry standards? As we do this, we also mix in new topics, sprinkle in new terms and concepts, and add a dash of calculations and (gasp), math and arithmetic. As we relate each topic to the next, biology isn't seen as a bunch of memorization of terms or stand-alone science experiments, everything is connected and what we learn from this may have an affect on how we think of that.

I love my job, by the way, and this method of teaching really brings it home for my future science teachers. They love doing each lab and going to the next logical step (the next lab, which I already have designed and ready for them...)

[european]

Consequently, I had to learn the hard way that everything has to start from the connections to their daily lives because they often discount whatever we do in lab or class as fake and mere examples of that "crazy science professor thinking" to modify Dr_Strangelove's phrase.

Interesting. I was aware of this argument as an Aristotelian objection to the notion of controlled experiment itself, but it seems to still exist.

[cc_alan]

To take a turn in direction, if anyone has any ideas about how to get my seriously math-phobic students to really get the hang of graphs in short order, I'm all ears.  My students are slightly more on track with that than G_H's.  I told them to slap a line of best fit through the data and they did.  Then, in the slots for the recording of two points on that line, they promptly recorded two random data points from the original data set with no regard for whether those points were on the line, in spite of my explicit instructions about how to select points that lay on the line and were at the intersection of the grid so that one could easily read them off the plot.

I have the *same* problem with my chem students. I don't think they really understand what a line of best-fit represents. They look at it as a line on the paper with no connection to the data.

Alan

[luvstowrite]

To take a turn in direction, if anyone has any ideas about how to get my seriously math-phobic students to really get the hang of graphs in short order, I'm all ears.  My students are slightly more on track with that than G_H's.  I told them to slap a line of best fit through the data and they did.  Then, in the slots for the recording of two points on that line, they promptly recorded two random data points from the original data set with no regard for whether those points were on the line, in spite of my explicit instructions about how to select points that lay on the line and were at the intersection of the grid so that one could easily read them off the plot.

I have the *same* problem with my chem students. I don't think they really understand what a line of best-fit represents. They look at it as a line on the paper with no connection to the data.

Alan

Can you discuss regression and how that helps us make better decisions with new points of interest?

[cc_alan]

To take a turn in direction, if anyone has any ideas about how to get my seriously math-phobic students to really get the hang of graphs in short order, I'm all ears.  My students are slightly more on track with that than G_H's.  I told them to slap a line of best fit through the data and they did.  Then, in the slots for the recording of two points on that line, they promptly recorded two random data points from the original data set with no regard for whether those points were on the line, in spite of my explicit instructions about how to select points that lay on the line and were at the intersection of the grid so that one could easily read them off the plot.

I have the *same* problem with my chem students. I don't think they really understand what a line of best-fit represents. They look at it as a line on the paper with no connection to the data.

Alan

Can you discuss regression and how that helps us make better decisions with new points of interest?

I'm not sure if our experiences correlate well.

Alan

[msparticularity]

Consequently, I had to learn the hard way that everything has to start from the connections to their daily lives because they often discount whatever we do in lab or class as fake and mere examples of that "crazy science professor thinking" to modify Dr_Strangelove's phrase.

Interesting. I was aware of this argument as an Aristotelian objection to the notion of controlled experiment itself, but it seems to still exist.

Richard Duschl has done quite a bit of writing about the difficulties of overcoming naive beliefs in science classes so they can be replaced by actual information. A friend of mine made a chart of it for me one time during a conversation, and there was this big blob in the middle that said "very messy." So it is.

[polly_mer]

To take a turn in direction, if anyone has any ideas about how to get my seriously math-phobic students to really get the hang of graphs in short order, I'm all ears.  My students are slightly more on track with that than G_H's.  I told them to slap a line of best fit through the data and they did.  Then, in the slots for the recording of two points on that line, they promptly recorded two random data points from the original data set with no regard for whether those points were on the line, in spite of my explicit instructions about how to select points that lay on the line and were at the intersection of the grid so that one could easily read them off the plot.

I have the *same* problem with my chem students. I don't think they really understand what a line of best-fit represents. They look at it as a line on the paper with no connection to the data.

Alan

Can you discuss regression and how that helps us make better decisions with new points of interest?

I'm not sure if our experiences correlate well.

Don't be lazy.  Plot it up and look.  Sheesh.

<serious hat on>
The biggest problem, Luvstowrite, is that students don't grok the graph.  They will make a graph because we told them to do so.  They will stick a line through the data because that's what you do with data on a graph.  But they often are seriously missing the point.  Even after I explained about how to construct a line of best fit by moving your ruler so that it touches as many points as possible before drawing your line, I still had several connect-the-dots pictures submitted instead of lines of best fit.  In spite of my demonstration with how to make Y versus X plot (X goes along the bottom, Y goes along the side, everything is labeled including units), I get random stuff where students apparently arbitrarily decide each point whether X or Y is listed first in the (x,y) pair even though the sheet has two columns of five blanks with each blank labeled in order something useful like x1 (first column, first row) or y5 (second column, fifth row) and I demonstrated how to go over x spaces and up y spaces before putting a point.

Even when I have the students plot using Excel and show them how to check the display equation box, they often cannot tell me what the slope of the line is.  Every class, I have at least one conversation about how the slope of the line is positive for this graph just like they vaguely remember from math class; the negative number in the equation is the intercept.

Talking about regression and correlation before I can get them to reliably put points on a graph and read points off of a graph is putting the cart way before the horse.

[southerntransplant]

Even when I have the students plot using Excel and show them how to check the display equation box, they often cannot tell me what the slope of the line is.  Every class, I have at least one conversation about how the slope of the line is positive for this graph just like they vaguely remember from math class; the negative number in the equation is the intercept.

And even when they manage to do all that, they don't tell you what the graphs mean. No interpretation at all. I even see this in grad classes. It's like, "Here's the damn graph you wanted. Happy now?"

[polly_mer]

Even when I have the students plot using Excel and show them how to check the display equation box, they often cannot tell me what the slope of the line is.  Every class, I have at least one conversation about how the slope of the line is positive for this graph just like they vaguely remember from math class; the negative number in the equation is the intercept.

And even when they manage to do all that, they don't tell you what the graphs mean. No interpretation at all. I even see this in grad classes. It's like, "Here's the damn graph you wanted. Happy now?"

Interestingly, my upper-level engineering students don't pull that nonsense.  After we had the first quiz on what should have been review material that was bombed by most of my students (average score of 12/40 with a low of 4, a high of 24, and I'm pretty generous with partial credit), they got with the program and started using their brains.  They've become pretty good about asking for necessary clarifications and actually coming to office hours with their class notes in hand to ask about "I've never seen this before.  Could you possibly clarify these points because I think I get the physical situation, but I'm not following the math?"

Now, my science for teachers sections still have a lot of what Conjugate described upthread with "I tried this and you marked it wrong.  I tried that and you marked it wrong.  I tried the other and you marked it wrong.  Just tell me what the hell you want and I'll do it, but stop making me read your mind" for things that shouldn't be mind reading exercises like "summarize your results in a paragraph that would tell your friends who didn't do the lab everything they would need to know for a quiz".  Apparently, they do not understand the words "summarize" or "results"...or possibly "friends"; I don't know because I'm at a loss for what to do with a paragraph that just lists the steps taken with no interpretation from the ten graphs that were part of the lab.

[galactic_hedgehog]

The biggest problem, Luvstowrite, is that students don't grok the graph.  They will make a graph because we told them to do so.  They will stick a line through the data because that's what you do with data on a graph.  But they often are seriously missing the point.  Even after I explained about how to construct a line of best fit by moving your ruler so that it touches as many points as possible before drawing your line, I still had several connect-the-dots pictures submitted instead of lines of best fit.  In spite of my demonstration with how to make Y versus X plot (X goes along the bottom, Y goes along the side, everything is labeled including units), I get random stuff where students apparently arbitrarily decide each point whether X or Y is listed first in the (x,y) pair even though the sheet has two columns of five blanks with each blank labeled in order something useful like x1 (first column, first row) or y5 (second column, fifth row) and I demonstrated how to go over x spaces and up y spaces before putting a point.

Another problem I see: inconsistent spacing.  Not just poor a poor choice (7 boxes for 5 meters?)  because they stretch the axes out to fill the paper in completely (and there are those that use very little of the paper, as well) regardless of whether the math comes out evenly, but sometimes there are weird jumps: 7 boxes, then 6, then 4...