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Archive for the ‘physical science’ Category

Today’s freebie is my collection of digital notebook documents for the 6th grade chemistry unit. See the earlier posts with more documents for scientific inquiry and ecology. To learn more about why I use digital notebooks and how to set them up, check out my digital notebook page here.

Chemistry Unit

chemistry mouseoverAlthough I call this a chemistry unit to my students, it’s really more of an introduction to matter. It’s not until 7th and  8th grade that our science curriculum delves into a close study of the periodic table and specific chemical reactions. The main learning goals for this unit include learning how to classify matter (substances and mixtures), measuring matter (volume, mass and density), and describing the states of matter and how they change. Some parts of this unit were adapted from the FOSS unit Mixtures and Solutions (which I love from my days teaching elementary), and the culminating CSI project was conceived entirely by my creative predecessor Krista Bouhaidar.  (more…)

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and no teacher hears it, what’s the point of putting together the workshop in the first place?

Or at least that’s how I felt last week when a grand total of 1 teacher showed up for my after school PLOT (Professional Learning Opportunities for Teachers) workshop about revising the scientific method. But even if the workshop didn’t happen quite as I had imagined it- with lively dialogue and moments of hands-on discovery- at least I can share it here, on the blog I’ve been neglecting so badly the past month. Here’s how the Scientific Method Makeover workshop was supposed to go down…

I’ve already detailed my thoughts behind revising and updating the tired and unrealistic scientific method on this post, so I won’t repeat myself here. Suffice it to say that the scientific method we learned as kids needs a makeover, but I do believe in teaching the process of science- as long as it’s flexible enough to incorporate the different ways scientists actually learn. My attempt at improvement is the scientific cycle:

How does this cycle work? Let’s put it into action and find out! Since it’s getting a little cold these days in Qatar (down into the 60s at night- brrrr!) everyone’s probably wondering where they stashed their portable electric heaters (buildings in Qatar don’t have centralized heat for obvious reasons). But how does an electric heater really work? We have your question– Boom! The scientific cycle commences, this time for a bout of secondary-source learning, aka research. Before diving into Google, I have teachers take a step back in the cycle and try to pre-explain how an electric heater works. Getting those preconceptions out there is important to encourage further questions and critical thought about any misconceptions that might exists. Got a vague and probably incorrect notion of how they work?? Great- back to Google, let’s investigate.

I give teachers a few guiding research questions to investigate on their own, then and there on their laptops:

  • How do electric heaters work?
  • What are electric heaters made of? (in particular the heating element)
  • How does electrical energy turn into heat energy?

Now everyone’s research and comprehension will be a little different, so to analyze their research findings I have teachers share and compare in small groups for a few minutes. Really, they’re a doing a synthesis of their research- compiling information from different sources and reconciling any discrepancies, which in turn gives them a better understanding of the “data”, in this case their research.

To explain I have them draw and label a picture explaining how an electric heater works. Better understanding than your pre-explanation? You betcha. In a nutshell, that was a much-simplified scientific round of research. It’s important to note that it might not be such a clean flowing cycle though- new questions could come up and cause a scientist to go back and re-investigate, or compare findings with someone else to re-analyze. But the general process is there: question-investigate-analyze-explain.

But wait- what about experimentation and all that? Let’s do another round of the cycle, but this time it’s hands-on. How do scientists answer a question when there’s nothing in the research to help? Let’s do an experimental cycle…

I show the teachers how a coil of wire attached to a D-cell battery creates a very simple electric heater (similar to the electromagnet circuit at right, except no nail necessary, wrap around a thermometer bulb instead). Technically it’s a short circuit, so the current is trying to race through, only slowed by the resistance in the wire, which generates heat. Hmmm… I wonder if it matters what kind of wire we use- some are thicker, some are thinner. Which wire would make the best heater? As before, let’s make a prediction, our pre-explanation, which we will revisit and revise later. And we’re off, investigating by having teachers creating a quick controlled experiment, something to the tune of comparing the different thicknesses of wire (but same length) in identical circuits, and wrapping the coils around thermometers to measure the temperature increase.

After 60 seconds of heating we’ve got some data, let’s analyze: in this case we can use mathematics to add different groups of teachers’ data together and find the mean for each thickness of wire. This has the same effect of doing repeated trials for accuracy (as long as we did a decent job controlling variables). A few calculations, and what do we find…. Try it yourself! Sorry, the elementary teacher in me just can’t spoil the excitement of discovery for you. Just try it out- I was excited myself to discover the difference, especially when it started to make sense, which brings us to…

Explain by writing a conclusion statement, supporting your claim with evidence. And there you have it, two complete tours of the scientific cycle in under an hour, with hopefully a demonstration of how versatile and useful the scientific cycle is as a new-and-improved scientific method. Whether you’re doing research-based investigations or experimental ones, the same general process applies. So the cycle is a framework, reminding students of the importance of making predictions (pre-explain), critical thinking (analyze) and meaning-making (explain). It also serves as a reminder of the cyclical process of scientific learning, as one question leads to another. The scientific skills at each step can vary, and with practice students could even learn to decide which skill would be appropriate to use as the learning demands.

End scene. I’m still wondering how this workshop would actually fly in real life, but in the meantime I’d be satisfied with any thoughts or comments you have (especially if you try your own electric heater experiment!).

 

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Khan Academy has stirred up a lot of debate among educators about the value of video lectures. On one hand the proponents tout the fact that students can watch them on their own time, at their own pace, and review again if needed. Some educators (like these guys) have even been employing video long before Khan’s rapid rise to notoriety, using video lectures to “flip the classroom” so valuable school time isn’t wasted on something students could just watch at home. The critics of Khan call foul because of the questionable value of lecture itself. A lecture on YouTube is still a lecture, a one-size-fits-all, listen-and-receive-my-knowledge affair. If lecture shouldn’t play a large role in the classroom, what is there to be “flipped” in the first place?

I agree with the critics that KA isn’t anything new under the sun. The media spotlight it enjoys is more about our country’s need to find a new direction in education than any new brilliance of KA. In fact beyond the videos, the “gameafication” of learning that has been created by KA team for teaching math through incentivized drills has much more in common with old-red-school-house pedagogy (Frank lays this out well here).

But despite all the flaws in KA-style teaching, lectures are still an occasionally useful tool in a teacher’s arsenal, and a video lecture probably even more so. So let’s not flush video lectures down the toilet in our disgust at the media’s KA lovefest, instead let’s figure out what this tool is good for. Without further ado, here are my 4 S’s for the best use of video lectures:

  • Short: This should go without saying. Any form of direct instruction needs to stay within the confines of its audience’s attention span. For my elementary students this seems like 2 to 3 minutes.
  • Shallow: If well done, students will remember the content of a video lecture, but only on a shallow, memorized level. Without first-hand experience and mental engagement to let them process the idea in their own mind, there’s not much opportunity for any deep understanding to be created. So keep expectations for learning shallow.
  • Sticky: I mean this in the Malcolm Gladwell sense, not like the gum on your shoe. For the (admittedly shallow) learning to take root, the video lecture must have some memorable appeal that sticks with you: humor, intrigue, a storyline, whatever. I usually opt for humor, maybe because I secretly wish I was Bill Nye.
  • Spot-on: How many times have you teachers out there put on a video for review and realized midway through that it’s not quite what you had hoped? (I know I have!) Maybe the vocabulary doesn’t match what you’ve been using in class, maybe the approach is too complicated or too simple, but it just isn’t fitting for your students’ needs- and you end up with more confusion than when you started “reviewing”. A good video lecture needs to be crafted for a very specific audience and purpose- most generic videos won’t cut it.
How do I put these into practice? I end up making a lot of my own short video lectures to teach scientific vocabulary or review simple facts. It’s not as dramatic as a flipped classroom, but it does mean small bits of direct instruction and basic review can be done at home, and available to the students who need it more than once. I know there are plenty of pre-made video lectures out there already on the internets (BrainPop is a biggie at my school, and is useful at times), but nothing beats a teaching tool that’s been crafted especially for a specific learning purpose. Plus students have a weird fascination with seeing their teachers on-screen. Maybe it’s the era of reality TV we live in, but sometimes I get the feeling that they listen more carefully to video me than actual me!
To give you an idea of what I’m talking about, here’s a few of the videos that I’ve made for our 2nd grade Forces and Motion unit. They were all edited using iMovie, and I swear I didn’t spend more than an hour or two making each one. In fact the gravity video I made yesterday in about a period. So from a cost-benefit analysis perspective, video lectures of this kind are a win-win, even if they don’t deserve headlines about “revolutionizing education”.  As long as video lectures are used as a supplement to thoughtful, contextual, inquiry-based learning experiences, they are tool teachers should keep handy.

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My 3rd graders will soon begin their first science unit on light and sound, which in my opinion is a great way to start the year- it’s hard to beat making noise and playing with flashlights. Despite all the hands-on investigations that we’ve done in the past though, there’s always one phenomenon that students have trouble with: refraction, the bending of light. 

I think refraction stumps students because it contradicts their particle-based intuition. Other kinds of light behavior (absorption, reflection, and transmission) make sense even from a particle perspective because they have simple analogies: a sponge absorbing water, a ball bouncing off the ground, sand passing through a sieve. But light bending inside something?? It’s a lot to wrap your head around, even for teachers.

Since we tend to stick to observable phenomenon in elementary science, we don’t get into a discussion of light changing speeds in different mediums (not that that makes it any easier to comprehend anyway!). Instead we merely observe different examples of refraction: a “broken” pencil in water, lens magnification, prism-made rainbows, etc. Sure, students can be trained to say that refracting light is “bending”, but that’s only a superficial understanding of the phenomenon- why bother? This would seem to make refraction a candidate for the chopping block with the new effort to trim standards to only core ideas, but even in the new framework refraction is suggested at the elementary level:

[By the end of 5th grade students should understand that]… because lenses bend light beams, they can be used, singly or in combination, to provide magnified images of objects too small or too far away to be seen with the naked eye. (page 108)

So, how to deepen student’s understanding about refraction? Similar to my past post about making sound waves visible, this year I’m planning on using a simulation to supplement the experimental observation, and hopefully deepen student’s understanding. The simulation is called Bending Light from PhET, the University of Colorado at Boulder’s fantastic treasure-trove of free, online physics simulations. Most of the simulations are intended for older students, like this one is, but the interface is user-friendly enough that I think even my 3rd graders will be able to get a lot out of it. From my Master’s in Ed days though, I remember reading that the main shortfall of using simulations is that students don’t always make the connection between real-life and the simulation. To avoid this, I’m going to try using the simulation and real-life observations in tandem.

For example, take one of our more traditional investigations, like observing the effects of concave and convex lenses. Students would usually look at a penny under the lenses and notice that the convex lens makes the penny look bigger, while the concave lens makes the penny look smaller. Big deal. Why do the different shaped lenses do this? Ummm…. What the students can’t observe easily is the bending of the light, so the lesson usually ends with me drawing a bunch of complicated looking ray diagrams on the board… and the students looking on blankly.

Let’s try that again. This year, right after students observe one the effect of one of the lenses on the penny, they’ll use the simulation to recreate the same setup. Take a look at the simulation screenshot of light shining through a convex lens. 

The cool thing about the simulation is that it shows what the light rays are actually doing with a simple ray diagram. So although they won’t necessarily understanding why refraction is occurring, they should get a deeper understanding of what is happening to the light. In the case with the convex lens above, the light is being bent together (or focused) so it makes objects appear bigger.

However, I should admit that I think there’s going to need to be some prep work done before we roll out the simulations to ensure that students understand what a ray diagram is in the first place. Since we begin the unit the more straightforward light behaviors, that would be a good time to introduce simple ray diagrams as a way of drawing what’s happening to light. For example, students should be able to observe and then draw what happens when light shines on glass: most of the rays transmit and a few are reflected. If students can grasp the ray diagram representation of light, and connect their observations of real-life with the simulations, I think their understanding of light will really shine this year (sorry, couldn’t resist :).

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Over my years of teaching I’ve probably used Google image search about 10,000 times. I like to create a lot of my assessments and worksheets from scratch, so I’m constantly searching for that perfect photo or piece of clip art to illustrate something. But as others in the bloggossphere like Dan Meyer have pointed out, using hokey clip art in this age of giga-pixelated multimedia is inexcusable. Using videos in the place of clip art leverages the engaging and real-world qualities of a video clip, and encourages students to see the science in real life. So, this year I’m going to experiment with video assessments. The idea behind a video assessment is that students will watch a video and then explain it demonstrating their scientific understanding (as a side note- videos could also be used to great effect for introducing a new concept, or could even be made by  students themselves to demonstrate understanding- but this is for another post!).

The inspiration for this came from Greg Schwanbeck and his post on dy/dan a couple weeks ago. In the comment thread one of the teachers asked about the logistics of doing a video assessment in the classroom, and it is a little tricky. After all, you want students to be able to watch the video at their own leisure, and go back to a certain part if they want. Anyway, I gave this some thought, and I’ll share with you my prototype Video Assessment 1.0 for your critique: click here to check it out.

The assessment is admittedly simple- I’m just reworking a pre-assessment that I give to my second graders at the beginning of their unit on Forces and Motion. What I’m looking for as a teacher is to see whether they can identify the kinds of pushes and pulls acting in each video, and whether they are familiar with their scientific names (friction, gravity, etc), and any misconceptions they hold. I would also like to include a clip with magnetic force, but try as I might I couldn’t find a good one, so I’ll probably just have to film one myself.

The webpage for the assessment was made using GoogleSites, which allowed me to embed the questions from a GoogleForm that I created (both of these Google tools are free, and I highly recommend using GoogleDocs if you aren’t already). There is an option to embed videos from YouTube directly, but because I wanted to resize the videos to make them fit together tightly on the page, I first ripped them from YouTube using this website and then uploaded them to GoogleDocs in the GoogleVideo format, which lets you resize them.

The cool thing about using GoogleForms for an assessment like this is that when students click “Submit”, their responses are automatically collected in a spreadsheet for you. I work with seven 2nd grade classes at my school, so this is a very seamless way to collect a lot of data. All I’ll need to do is simply send the link of the assessment webpage to teachers so they can share with their students. By using laptop carts and headphones, each student will get their own laptop so they can do the assessment on their own and watch the videos as many times as they need.

One design issue I have is that I would prefer to place each video directly next to the question, but GoogleForms doesn’t allow for embedding videos. So students will have to do a lot of scrolling up and down between watching videos and answering questions. Anyway, we’ll see how it goes down- but in the meantime I would appreciate any constructive criticism you have.

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My 3rd graders will be starting of the year with a unit on sound and light, which has always been one of my favorites (so much to play with and observe, and so obviously relevant to students’ lives). The sound part of our unit is pretty heavily based on the FOSS unit Physics of Sound which many teachers are probably familiar with. However, there appear to be some changes coming down the pipeline with the impending national science curriculum and this summer’s release of the K-12 science framework from the NRC (for a primer on this, check out this article from Education Week) The new framework has a new approach to physical science standards that could change the emphasis of units like mine.

Instead of grouping sound and energy under energy standards, as many standards documents have done in the past- the NRC’s committee decided to create a separate physical science standard called “Waves and their applications in technologies for information transfer”. Whoah- that’s a mouthful, but it’s cool to see information technology specifically mentioned. Why call out waves specifically? In the committee’s words on page 88:

This idea is included in recognition of the fact that organizing science instruction around core disciplinary ideas tends to leave out the applications of those ideas. The committee included this fourth idea to stress the interplay of physical science and technology, as well as to expand student’’s understanding of light and sound as mechanisms of both energy transfer and transfer of information between objects that are not in contact.” 

I think this is dead on: even thinking about my own unit, we spend a lot of time playing with tuning forks and flashlights, but very rarely emphasize more technological applications such as speakers or radio waves. I realize there are developmental reasons to keep a sound and light focused on observable, visible phenomenon, but surely there are ways to make technological applications of waves more accessible to elementary and middle school students. Here’s one idea that I’ve used with success in the past to make sound waves visible:

Get a sound microphone probe, such as the one sold by Vernier at right. No need to buy one- I borrowed one from my high school physics department, so ask there first. You’ll also need to borrow the software that goes along with the probe to graph it’s output, for example Logger Pro . Now it’s time to play- get the probe set up to collect data, and put it near an instrument that can create pure tones (a electronic keyboard works well, especially on a setting like “Whistle”). Start collecting data and playing your instrument, and you should see the data graphing from the probe. It will look like a mess at first- so stop recording and play with the axes of the graph. You’ll need to stretch out time on the x-axis because most audible sound waves will be so packed together you won’t be able to see the wave. Once you’ve stretched out the x-axis enough that you can see a wave (like the one pictured ont the left), now comes the fun part! Start collecting data again, and experiment with playing notes at higher and lower pitches as well as louder and softer volumes. Pretty neat, huh? You’ll be able to see exactly how the sound wave  changes- how volume is related to the height of the wave and pitch is related to it’s wavelength (or speed of vibration).

Once you’ve got the hang of it, any invisible sound wave can be made visible… which can lead to all sorts of class investigations. I wish I could find an online version of a sound wave visualizer that utilizes a laptop’s built-in mic, because that could allow many students to work with it at the same time. If anyone out there knows of one- let me know!

Any other ideas out there? How else can traditional teaching of waves be updated to include modern technology applications? I’m all ears!

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