1. Light travels in a straight line. What is the evidence for this?
You cannot see around a corner! You only see something when the light that bounces off an object reaches your eye. You must be in the direct line of sight in order for them to reach your eye. https://www.youtube.com/watch?v=2nwK78F_4eA for more information.
2. When do light rays bend? What is the evidence for this?
Light rays bend when they change medium and hit at an angle. When we did the demonstration in class, the line of students changed direction when they entered the “slower” medium. Please see http://www.physicsclassroom.com/class/refrn/Lesson-1/The-Cause-of-Refraction if you want further clarification.
Other evidence of light rays bending was the appearance of a pencil or ruler placed in a glass beaker of water.
The part of the pencil in the water: When light reflected from the pencil reached your eye it traveled through the water and when it reached the curved surface of the glass, it changed direction when it changed medium – because the glass was curved, the light rays did not bend equally and therefore the image appeared magnified. The light rays reached your eye in a slightly different position.
The part of the pencil in the air: The light did not change medium, but traveled in air the whole time. The light rays stayed in the same relationship to each other and the image your eye perceived was not magnified.
When you looked at the pencil in the water, it appeared to be “broken” at the water line. This was because only part of the image of the pencil was magnified.
We looked through a triangular glass prism and saw that the laser beam was bent and did not travel in a straight line. We also saw that the prism refracted sunlight into a “rainbow” of colors.
3. A lens makes light rays focus at one point. This is called a focal point. What is the evidence for this?
When you looked through the magnifying glass you were able to focus the sun’s light to a single point. Some people used a flashlight to get the same effect.
When we projected the image of the window onto a piece of paper, there was one particular distance when the image was clear and upside down. This distance was the focal distance of the lens.
We saw that the differently curved lenses had different focal points.
4. A shadow happens when light rays are blocked.
This is evidence that light travels in a straight line. https://www.youtube.com/watch?v=2nwK78F_4eA provides more information.
5. You only see light when it is reflected into your eyeball.
Light can be there but we cannot see it unless it strikes something and gets reflected into the eye. A laser beam can only be seen when it strikes a surface such as a floor or the wall. However, when we placed a piece of paper in the air in front of the path of the laser light, the light reflected off the paper and traveled to our eye, so we could see it.
6. Convex lenses curve out. These are the kinds of lenses that magnify.
We saw that the magnifying glasses used convex lenses.
7. Why do objects appear black?
Black objects absorb all the light that reaches them. No light rays are reflected back to your eye.
September 17th, 2016 · JBMS
October 27th, 2015 · designing group-work, learning through discussion, STEM Education
These children are engaged in what developmental psychologist Barbara Rogoff calls “intent participation.” Each group is learning to perform an engineering task with no teacher. The girls at upper left are constructing a book support out of newspapers and masking tape. The other two groups are constructing parachutes out of coffee filters. None of them has been taught how to complete the product. They are learning what they are already doing.
The notion that a teacher, someone with knowledge, must tell learners what they should be thinking is the single most crippling unintended result of Modern European-American style education. Most Americans leave school feeling stupid, because they are unable to figure out what teachers are telling them to think. No wonder American students continue to perform so poorly on measures of problem-solving and critical thinking. If we want children to think for themselves they must have opportunities and encouragement to do so.
I am not, of course, talking about the elite children, those who are able to guess what the teacher is thinking and reproduce it. My experience is that most such children, who get good grades and score high on standardized tests, have a very difficult time performing unstructured tasks that have more than one solution. They wait to be told what to do.
Anyway, if we want self-reliant learners, who can figure things out for themselves, children must work in groups with peers with the guidance of an adult.
More tomorrow about learning in groups…
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October 14th, 2015 · Politics and education, Standards and accountability
I’m going to be a little poetic here. By which I mean turning my attention to that which is not tangible.
I have the opportunity right now to work one-on-one with several children. It’s a chance to go back to basics: children want love, acceptance, security. They want to find out about the world, while being respected as valuable. Cliches. And so easy to lose sight of when you are engaging with big issues of school reform, achievement gaps and standardized testing.
I live across the street from an elementary school. Every school day starting about 7:30 the cars start jamming the road. Right next door to our building is a large, usually empty parking lot with signs posted everywhere: No School Parking. People park there anyway, hurry their children out of the car, shepherd them through the tangle of behemoth SUV’s driven by people who patiently or impatiently seek to thread their way through the obstacles of cars and human bodies. By the time the school bell rings at 7:50, things have quieted down, a few stragglers, and by 8:00 all is quiet again until the loudspeaker starts blaring announcements.
I remember announcements; it was an unremarkable feature of school life, just like standing in lines. Socializing children to being managed, to take their places as bodies in the machine where everything is monetized.
What would it take, I wonder, to educate (in the original meaning of the word, “to draw out”) the mass of children? They are, in fact, not the mass, but individuals looking for love. Any good teacher knows this, which is why there is so much resistance to standardization of education. The goal of education is to engage with children in the kinds of relationships that will draw out the beauty of the human soul.
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June 5th, 2015 · professional information
Please scroll down to the links to the right.
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June 4th, 2015 · STEM teacher education
Critical Place-Based Teacher Education
In the current climate of accountability and standardization in (teacher) education, the prospect of PBE taking root seems preposterous. And Dr. D. does not suggest that this particular foray into PBE is exemplary. The process of participating in the research, both by observing in classrooms in a focused and local way has been crucial, as was the literature we reviewed, and the teacher candidates’ reading of the various drafts of this paper.
We leave the reader with Jolynn’s reflections on PBE for her future students:
Given the rich history of the area, we are now left with what to do with it. We have made ourselves accountable by discovering such a rich history and now must attempt to use it to structure lessons. When beginning the process of creating a place-based lesson, we must do what has already been done in this instance, and find out the history of the place and the people. When considering a place’s history, we must also juxtapose that with the present. Each school year brings along with it changes in the type of learners, and as teachers, comfortable in the ways in which we were taught and how we learn, we must not forget this. Student surveys of their personal learning styles as well as their intelligences (Silver et al., 2000) help us to understand more about their “place.” When we begin to incorporate all of this, the term “place” begins to take on a new meaning. What is “place” to our students and how can we connect that with the environment around them and the history and culture of the territory they inhabit? For example, in a science lesson centered around the Jones County history, we would delve into the ecology of the county and how it was shaped by its history and agricultural practices that have left the area in its current state. When beginning a lesson such as this, we would need to get the students involved in the history by choosing a location that can share a story. This story will become the thread of the lesson and a historical timeline that the students will be able to reference with ease. This “story” also coincides with the culture of the area, as southern practices dictate history be passed down from person to person in a narrative format. Then we begin to involve scientific practices such as surveying the flora and fauna of the area as well as investigating areas of succession and human impact on the environment. Of course these scientific practices can be taught in other styles and formats, but by giving the students an anchor they can tie this information to, we are ensuring that the students are able to apply this information rather than simple memorization as well as instilling a sense of accountability to them for their environment and culture. This style of teaching requires that the educator go above and beyond the textbook, and certainly not be considered for those with concern for teaching to the test. But when enacted correctly, standards, evaluations, and course tests come simply and pleasantly as the teacher and student are both comfortable and confident with their knowledge of the material and their surroundings.
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March 1st, 2015 · College teaching, STEM teacher education
For the last 6 weeks I’ve been teaching a 6-hour face to face class on Saturdays to a group of pre-service teachers in an MAT program and in-service teachers getting advanced degrees. This has been brutal for everyone concerned, to say the least. I’ve had to pare down my expectations because after about 4 hours nobody can absorb much, no matter how many times I asked them to get out of their seats and try something different.
I decided to focus on Stigler & Hiebert’s The Teaching Gap, which is old news, but not to the students, so that they would be open to questioning their cultural assumptions about what it means to teach science and mathematics. My plan was this would allow them to be open to reform ideas, such as those embodied in the Tools 4 Teaching Science out of the University of Washington.
I think this pretty much worked. In our last class today I asked the students to make concept maps. I gave each person a page of stickers with 60 nouns culled from a variety of class readings:
- The biology people read The Beak of the Finch, which most hated because it is tedious in spots. The math people read either Jacqueline Leonard’s book on multicultural mathematics education or the Joy of X. The purpose was to increase content knowledge, which I think was modestly successful.
- Magdalene Lampert, “When the Problem is not the Question and the Solution is not the answer.” We used the theoretical framework of this article to think about what it means to do mathematics (and science).
- Hand et al., Negotiating Science. We used this to provide a framework for inquiry activities in science.
- 5 Practices for Orchestrating Productive Mathematics Discussions.
That was actually quite a lot of reading for 6 weeks. We only got through Chapter 7 of The Teaching Gap, since that is the point after which the authors mostly just repeat themselves.
I gave each student a giant Post-It and asked him or her to do a concept map using Novak and Gowin’s 1984 procedure and using their scoring scheme. http://www.flaguide.org/cat/conmap/conmapfig5.php
Several students struggled mightily with this format. More about struggling later.
Thinking about the maps in public
I wanted the maps to be public records of thinking, but didn’t want to put anyone on the spot. Therefore each map was displayed on the wall and was only identified with a number. We did a gallery walk during lunch; I asked students to record on index cards what they thought was interesting or new about each map, and what was similar to what they put.
I collected those cards, and a first glance through them shows they didn’t write much. However I still think it was an important focus to help them look at other people’s maps, since they were all quite different.
We then went around to each map and talked about what the students saw in it. The easiest entry point for the students was surface features, how it was organized. Several remarked on people having chosen different starting points for the map.
About halfway through, I started pointing out things that I saw, going back to the earlier maps and comparing. Students stopped contributing much, once they realized I was going to tell them “the right answer.” Of course it wasn’t, but I was trying to get certain ways of thinking on the table. I think they also were at a loss as to what to say. The holistic approach, looking at where the maps went, what concepts had lots of links and what seemed isolated, was new to them. In making a quick instructional decision, I considered briefly that going with a cognitive apprenticeship model, in which I shared my thinking with them, was probably going to be most productive.
This was such a rich discussion, I want to get down as much as I remember and it might be an overly long and boring blog post. But I do want to capture what happened while it is still fresh in my mind.
I was aware that a person got very upset when I pointed out how a particular map showed that this set of ideas was not integrated with the rest of the map. (Someone appearing to get upset or embarrassed actually happened more than once.) I infer that the persons who seemed upset were the authors of the map in question. I was very careful to say, “This person did…” In truth, I knew who authored only 3 of the 13 maps. Because we were pretty much anonymous, so they were not singled out in public. It is interesting to me that several students seemed to feel that their maps were private performances that should not be critiqued in public. I’m an artist accustomed to having my drawings and paintings critiqued by art professors. Critiques are always scary, but they are also very powerful because they give the entire group the benefit of the instructor’s thinking.
I think of Fred Erickson repeating several times in my own grad school classes, “School is the only place where people must publicly display incompetence.” In spite of my repeating often to my own students that the right answer is how you’re thinking, not the content of what you say, the social practices surrounding school being about the right answers is still the dominant cultural model. In spite of my never saying that one of the maps was wrong, some students still interpreted my remarks as showing them up as incompetent.
I ended class saying the maps made me feel really good, that it was formative assessment for me, I can see what people got out of the class, and I’m pleased. I was. Of course the students wanted to know how I was going to grade them. I said, I’m going to write each of you a letter about your map, and I want you to write me back. (Even though class meetings are over, there is still an assignment out there to do a unit plan. Class is officially over in May.)
specific items that interested me
One of the maps had a strand that included “disciplinary language,” that was cross-linked to “writing,” which was also cross-linked to disciplinary practices. There was another independent strand that included “discussion,” that was linked to “teacher,” and not linked to disciplinary language or practice. I didn’t say anything public about this observation; I thought it might seem too critical. I will write to the author about it. I also note that our pre-service teachers have the most difficulty with the section of EdTPA having to do with academic language. That this shows up in at least one map is confirmation to me of the power of concept mapping.
One of the students who was having a really hard time, had chosen “knowledge” for her topic and “teacher” and “student” for the next level. As I walked around, she asked me for help. She couldn’t figure out to where put any of the other labels, and she couldn’t think of what to write as links. I asked her to clarify, what did she define the link between teacher and knowledge to be, and what was the link between student and knowledge. She replied, The teacher has knowledge, and the student has some knowledge. Without saying anything, I thought, This is the traditional transmission model of teaching, slightly updated to include students’ prior knowledge. I replied to her that she might try different concepts instead of student and teacher, maybe that was the problem. She was able to successfully complete the map.
to be continued…
February 17th, 2015 · College teaching, learning through discussion
I’ve been meaning to write about this for a week or so. I had occasion recently to visit a student teacher in a 7th grade life science class. The topic for the day was sexual and asexual reproduction. The lesson started out with a Brain Pop video. The plan was for a “class discussion” and then the students would take the Brain Pop quiz.
On the previous day, the students had each been given a handout on a plant or animal that reproduces asexually. I’m not quite sure what was done with the information, although I suspect groups made presentations to the class. At various points in the lesson the teacher asked them to refer back to “their” organism from yesterday.
The participation structure for the discussion followed the recitation script (IRE). The teacher asked questions about what was in the video and asked students to connect that information to the organisms they had researched. She affirmed whether or not the responses were accurate. Actually, not one student was able provide much in the way of a response, in fact, I’m pretty sure that any student who was called on, said, something like, “Um, I, I can’t remember the name of my animal.” The student were directed to look in their “interactive notebooks,” and after several seconds of silence, would say, “Oh yeah, yeast,” or “I can’t pronounce it.”
The students were genuinely trying. It appeared to me that they were not making the connections that were the intention of the lesson plans. The “discussion” involved quite a bit of silence. At this point I decided to step in. The rationale was that students seemed not to have incorporated the research on asexually-reproducing organisms into their watching of the Brain Pop video.
I hope the student teachers I “supervise” are used to me stepping in and modeling when I think it will do some good. I interrupted and asked the students, well a week later I can’t quite remember what I said. But the purpose was for students to provide their personal experiences with observing asexual reproduction. The discussion was lively and covered much ground. As I said to Betsy (pseudonym), the student teacher, afterwards, everyone is interested in sex and reproduction. It isn’t difficult to get a discussion going. Several of the ideas matched concepts from the Brain Pop video, although they were not referred to explicitly.
After 10 minutes, Betsy resumed her lesson plan and the students took the Brain Pop quiz. An overwhelming majority of the students got most of the answers wrong, in spite of the fact that they were designed to assess the very concepts students had volunteered during the class discussion.
Now I’m still thinking about this event. Clearly the students understood the concepts in the discussion and clearly they did not connect them with the formal instruction of the Brain Pop video. I remarked to Betsy that it appeared the students did not understand that the discussion was actually learning.
This has pretty profound implications. I will be writing more about this.
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February 15th, 2015 · College teaching
The other day someone asked me to provide an example of my “online teaching.” I explained some of the online assignments I’ve given, but the person continued, “No, I mean teaching.” It took me a few seconds to comprehend the question, that she was asking if I put my lectures online, or annotated videos. I still probably had a deer in the headlights look. You see, I don’t lecture. I consider that I’m engaging with students in instructional conversations.
Please see my earlier posts about learning through discussion, and also the rest of the category College teaching.
This past semester I have had conversations with students about their experiences with online courses. I was surprised to hear that they thought the discussion board assignments were busywork. Since I have used discussion boards quite extensively in the past, I was intrigued by this comment. When I pressed a little more, they said they did not write what they really think, but what they thought the instructor was looking for.
This has caused me to pause before such an assignment. This semester I asked students to upload concept maps to the discussion boards, but I must say it has not been as productive as I hoped.
In the past, I assigned discussion board postings, and students would always want to know how long it had to be. I settled on 300 words. Then I noticed that students were copying lengthy quotes into their postings. I had to forbid quotes longer than 10 words, and no more than one quote per posting. However, it seems to me I have to find a better way to design discussion boards so that students understand them as learning conversations.
I think the deeper issue is that students don’t understand discussion as being a way to learn. I just had an experience of this last week when I visited a student teacher in a 7th grade classroom, which will be the subject of my next post. I again refer you to the blog of December 2010, when I started writing about learning through discussion.
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