Sample Dimensions Essay: Dean Baird

Dimensions of Outstanding Teaching Written Response
Dimension One: Mastery of mathematics or science content appropriate for the grade level
taught.
The narrative for Dimension One should be no more than four pages.

1a. Discuss the mathematical or scientific ideas that are fundamental to understanding the chosen
topic or concept.

Why is the sky blue? The primary physical concept of the lesson is the atmospheric

scattering of light: Rayleigh scattering, to be specific. Diatomic nitrogen and oxygen molecules

in the atmosphere scatter light in a manner that is frequency-dependent. Ultraviolet light is

scattered best. From there, scattering decreases as frequency decreases. In the visible spectrum,

violet is scattered most and red is scattered least. This would suggest that the daytime sky should

be violet.

But the physiological principle of visual sensitivity also comes into play. We are most

sensitive to light near the center of the visible spectrum, corresponding to yellow-green. Our

sensitivity decreases as the color of light approaches either end of the spectrum, red or violet.

While violet light is scattered better than any other color, our eyes are not very sensitive to

violet. While our eyes are most sensitive to yellow-green light, yellow-green is not scattered very

well in the atmosphere.

Blue is the compromise of scattering and visual sensitivity. That is, blue is scattered well

enough and our eyes are sensitive enough to blue to make it the color of the daytime sky.

Scattering of the shorter wavelengths of visible light leads to sunrise and sunset skies

dominated by longer wavelengths. The geometry of sunrise and sunset requires sunlight to pass

through a thicker layer of atmosphere before reaching observers on the surface of the planet. The

shorter wavelengths (violet, blue, green, and even yellow) are scattered out from the sunlight by

PAEMST 2011 - Dimensions of Outstanding Teaching Written Response Page 1
Name: Dean Andrew Baird Teacher ID 24484

the time it reaches observers. Only the longer wavelengths (orange and red) penetrate deep into

this relatively thick layer of air.

1b. Explain why this topic or concept is important for students to learn and how it relates to more
complex concepts that students will encounter in subsequent lessons, grades, or courses.

The question of why the sky is blue is an age-old mystery that puzzles anyone with an

inquisitive mind who looks up at the daytime sky. It would be a shame for a student to emerge

from a year-long, high school physics course not knowing the answer. The fact that an

operational understanding of the blue sky requires the knowledge and balance of two factors—

frequency-dependent scattering and the sensitivity variation of human vision—makes this a

challenging lesson. Many details of scattering go beyond the scope of this lesson: why is it that

nitrogen and oxygen molecules resonate at ultraviolet frequencies? Resonance, itself, is a topic

explored in our AP Physics 2 course, where we try to unlock some of the secrets of musical

instruments, the destruction of the ill-fated Tacoma Narrows Bridge, and how modern building

codes attempt to limit destruction caused by earthquakes. Knowledge of mechanical resonance

provides a scaffolding that is helpful for understanding electromagnetic resonance, like that

found in inductor-resistor-capacitor (LRC) circuits. Students who study atmospheric optics will

add deeper findings to their understanding of Rayleigh scattering. They will learn the role of Mie

Theory in explaining the color of clouds and scattering caused by particulate matter in the

atmosphere. They will also learn why the light scattered to create the blue sky is also polarized to

various degrees. Our high school physics understanding of the blue sky is a beginning, not an

end.

1c. Discuss the misconceptions or misunderstandings that students typically have with regard to
this topic or concept.


Misconceptions for why the sky is blue are widely—if not firmly—held. Most students

(and people in general) believe the blue sky is somehow a reflection of the ocean. If pressed on

the matter, they will suggest that the ocean is blue because it is a reflection of the sky. Students

who live near an ocean are hard-pressed to explain blue skies over places, such as Kansas, that

are far from any ocean. More informed students will suggest that blue light is scattered best in

the atmosphere. This idea is closer to the accepted reason, but still falls short since it’s

technically incorrect (violet is scattered better than blue), and it fails to acknowledge the role of

human visual sensitivity. Prior to this lesson, most students were not aware that their eyes are

more sensitive to some colors than to others. This variation is not intuitively obvious, and it was

probably never taught in their previous science courses.


Dimension Two: Use of instructional methods and strategies that are appropriate for the
students in the class and that support student learning.
The narrative for Dimension Two should be no more than four pages.

2a. Describe the instructional approaches you used to help students understand the topic or
concept chosen in Dimension One.

My lesson is a combination of audio-visual presentation, demonstration, and lab group

activity. It begins by inviting students to record their prior knowledge about why the sky is blue.

There is an opportunity to question commonly held beliefs. With the preconceptions found

wanting, we begin our guided inquiry. We acknowledge that “sky” is just air: primarily nitrogen

and oxygen, and is colorless and transparent [Supplemental Page 1, Figure 2]. By looking at

photographs of the nighttime sky and daytime sky, we conclude that sunshine is a key

component to the blue sky [Figures 3 and 4]. By looking at an image of a sunlit lunar landscape

[Figure 5], we conclude that air is another key component of the blue sky. At this point, we must

delve into the sophisticated idea of scattering. The actual frequency-dependent scattering of light

is difficult to show in a classroom setting, so we detour into demonstration involving a pair of

resonant tuning forks [Figure 7]. We see that one tuning fork can be used to excite a second

tuning fork into vibration. The concept of resonance is briefly described. In this case, the sound

waves that traveled from the first tuning fork to the second tuning fork were scattered when the

second tuning fork went into vibration [Figure 8]. The success of the resonance (and therefore

the scattering) depends on the match of the natural frequencies of the two tuning forks.

A hypothetical question is then posed. Consider an array of various tuning forks

assembled across from an array of uniform, identical tuning forks. If all the forks in the “variety

array” were struck, would the forks in the “uniform array” be set into vibration? The answer is

“yes,” since there would be matches to the uniform forks in the variety-fork array [Figure 9].


The sun is then represented as an emitter of a spectrum of colors [Supplemental Page 2,

Figure 10]. The reaction of atmospheric molecules to spectral colors is illustrated [Figures 11–

13]. Violet is shown to scatter best and red is shown to scatter worst. The sensitivity of the

human eye is then discussed with supporting graphs [Figures 14–15]. Our eyes’ peak sensitivity

lies at the yellow-green center of the visible spectrum, and drops off toward the red and toward

the violet. We conclude that the blueness of the sky is a compromise between scattering and

sensitivity. Violet is scattered best, but we’re most sensitive to yellow-green. So the daytime sky

is blue. Next we simulate our own skies using “skinny fish tanks,” water, scattering agent (Mop-

and-Glo), and small, bright flashlights [Figure 16]. In doing so, we see that blue light scatters

near the point of entry while orange and red light to passes further into the “atmosphere.” Now

we can discuss how the same mechanism that produces the daytime blue sky also produces red

skies at sunrise and sunset [Figures 17–18].

2b. Explain how you identify and build on students’ prior knowledge, and how this knowledge is
addressed in your video and in your general teaching strategies.

Prior knowledge is explicitly elicited in the lesson [Video 0:00-3:30]. Since students

might be hesitant to record preconceptions as their own, they are asked to record what they think

other people might think about why the sky is blue. Students are generally uncomfortable

committing to their prior knowledge in physics. They’ve been wrong about something at some

point in the year. And even though there was no penalty for holding or expressing an incorrect

preconception, their reluctance to commit is human nature. Ascribing preconceptions to a third

party allows them to record it on paper while not feeling culpable if the idea proves false. Other

techniques used to bring out students’ prior knowledge include “checking your neighbor”

(discussing the matter with a classmate), pre-lab questions (usually completed as homework),

and the use of clickers with carefully constructed presentation surveys. During the lesson or upon


its completion, the prior knowledge can be acknowledged as being correct, incorrect, or perhaps

simply incomplete. In this lesson, I incorporate a misconception into the presentation [Video

2:00]. There is a trap in physics instruction as tempting as it is troublesome. That trap is the

heavy reliance on the discrepant event. While there is sometimes value in presenting a

demonstration whose outcome challenges strongly held misconceptions, it is possible to overuse

that technique. Students who feel they were fooled into errant predictions become weary of such

trickery and wary of future demonstrations. Some adopt a practice of intentionally predicting

outcomes they think are wrong. Physics becomes the class where nothing works the way it

should. In general, it can create a negative tone in the class. I prefer to make the most of a limited

use of the discrepant event. Like the tastiest chocolate mousse, a little goes a long way.

2c. Discuss the instructional strategies and techniques you use to meet the learning needs of all
students, challenging those with stronger knowledge while ensuring learning for less
accomplished students.

The classroom seating arrangement allows for eight lab groups of four students each. We

change seats every four weeks. When we do, I allow students limited choice over their seating

location in a process that ensures each lab group will have one student from each quartile based

on course performance. That is, every group of four will have one student each in the 1st, 2nd, 3rd,

and 4th quartile of academic performance in the course. Students are not made aware that this is

the goal, since announcing the goal would compromise confidentiality protocol. (Some students

might figure it out, but I change the grouping criterion on rare occasions to keep from making it

too obvious.) When labs are collected for grading, only one lab is picked up from each group. No

one in the group knows which lab will be collected, but everyone in the group is given the score

earned by that lab write-up. Lab partners therefore check each other’s work in a collaborative


manner. The strongest students make sure the weakest students keep up with the content of the

lab. No partner is left behind.

Another measure taken to ensure success across the spectrum is our Test Correction

Journal process. A unit test is given and subsequently scored. During the following unit, the

answer documents and tests are returned to students during class. Students record journal entries

for each test item they missed. If they missed eight items, they write eight entries. The entries

express the correct answer, using a complete statement that makes sense on its own. During the

next unit after that, a 10-item quiz is given. It’s made of items from the original unit test, now

two units past. Students surrender their journals to take the quiz. If they get all 10 quiz items

correct, I give them back half of the points they missed on the original test. Continuing with a

student who missed eight items, they likely missed 40 points, so their original score was 60.

With a perfect score on the quiz, they will earn back 20 points so that their score on the original

unit test becomes an 80. If their original score had been 90, they could have raised it to a 95. The

benefit is not an all-or-nothing proposition. It is pro-rated: students who score, say, 6 out of 10

on the quiz earn back 60% of half the points they missed. As cumbersome as it sounds, Excel

makes the accounting simple. The thrust of the process is that the weakest performers on the test

have the greatest opportunity for gain, but one can never recover everything they missed in the

first attempt. Are the strongest students left out in this process? No. During the journaling

process, test forms and student answer documents are returned to students, but answer keys are

not made available. Students must learn the correct answers and rationale from classmates. The

strongest students become the teachers during that process. I say as little as possible during test

correction journaling, preferring to listen as students teach students.


Dimension Three: Effective use of student assessments to evaluate, monitor, and improve
student learning.
The narrative for Dimension Three should be no more than three pages.

3a. Describe how you assessed student learning and achievement for the topic discussed in
Dimension One and shown on the video, and how you use what you learned from the assessment
to improve your teaching.

Student learning is assessed by inspection of the classroom worksheet [Supplemental

Pages 3-6], homework items relating to the lesson, and test items relating to the lesson. Test item

performance on “blue sky” items is typically above average. Homework performance is mixed.

Not all students choose to complete their homework assignments. Worksheet performance is

typically good, although most students will have one or more missed responses. It is rare to have

any student who is completely non-responsive on the classroom worksheet.

Student questions and responses during the lesson are among the best guides to future

modifications. This lesson has evolved over the years to include an improved audio-visual

presentation, and to include student interaction with the skinny fish tanks. Based on this year’s

discourse, I will research other animals’ visual sensitivities.

3b. Discuss other specific ways that you routinely assess and guide student learning. You may
include examples of formative or summative techniques, including student presentations,
projects, quizzes, unit exams, or other methods.

Classroom guided inquiry and demonstrations always include a strong classroom

discussion/debate element. So there is some assessment during the lessons, themselves. Some

lessons involve review or are simple enough so that successful performance can be expected on

the spot. We often use our clickers during such lessons and sections (2nd period, 4th period, etc.)

compete with one another to see who can get the best performance on each clicker question

posed. The use of clickers is limited so that students get very excited every time we use them.

The clickers never become routine or overused. The inter-class competition element prevents


would-be jokers from choosing wrong answers under cover of clicker anonymity. I learned that

from my early experience with clickers in the high school classroom.

Unit tests provide the clearest evidence of student learning. But different students learn

different topics at different rates. Content attainment among widely varying students is akin to

the settling that would occur in snow-globes filled with liquids of differing viscosities. Some get

things faster than others. (I say this as someone whose own snow-globe is filled with chilly

molasses.) Unit tests are structured to revisit old topics. A typical unit test will have a majority of

questions on the current unit, but will also include questions on topics from previous units. This

practice, combined with the Test Correction Journal process, allows students to have repeated

exposures to material and repeated opportunities to demonstrate success.

Students can also opt into another form of assessment by participating in our annual Open

House event, ExploratoRio. Participating students choose to build an exhibit, which is typically a

low-cost version of an exhibit from San Francisco’s famed Exploratorium. The students then act

as explainers of their exhibits during Open House Day, when we arrange visits from local

elementary students. They again act as explainers when parents visit during Open House Night.

Afterward, they must write a reflection in the form of “Notes to the Future,” which will be given

to next year’s demonstrators of their exhibit. Students are assessed on the quality of the build of

their exhibit, the enthusiasm and correctness of their explanations during visitations, and their

reflection.

3c. Provide evidence of your teaching effectiveness as measured by student achievement on
school, district or state assessments, or other external indicators of student learning or
achievement.

My students’ performance on the California Standards Test in Physics is typically better

than that of any other teacher’s students on any test at the school. About 65-80% of my students


perform at the advanced or proficient levels. The caliber of students who elect physics is part of

the reason for the high performance. But we typically have well over 200 students in physics.

More than half the school’s graduates take physics. Unlike many schools with an Algebra 2

and/or chemistry prerequisite, our only prerequisite for Physics 1 is successful completion of

Algebra 1. We have significant variation in the intentionally big tent of physics. We do not limit

the course, as was often done in the 1950s and ’60s, to the 20 smartest boys at the school.

One local school often posts Physics test results showing 90% or more of its students as

advanced or proficient. Closer examination reveals that far fewer students in the school (whose

overall enrollment is similar to my school’s) take the test. The number of students performing at

the advanced or proficient level is nearly equal at both schools.

My Advanced Placement Physics 2 students take the Physics B Examination at the end of

the school year. Over 90% of our candidates pass with a score of 3 or better. They have also

competed in the American Association of Physics Teachers’ (AAPT) Physics Bowl competition

exam since 1991. The AAPT recognizes the two top schools from each division (first-year or

second-year students) in each of 15 regions throughout North America. My students placed first

twice, and they placed second twice. Only one other school in the area has ever placed in Physics

Bowl, placing second one time.

My students have performed well in the Science Olympiad’s Physics Lab event,

achieving medal recognition in regional, state, and national competition.

One of my students, Jason Kamras, was recognized as National Teacher of the Year in

2005. I was very proud of him claimed no credit for an accomplishment that was his, alone. But

in post-recognition interviews, he acknowledged me as one of two teachers who deeply

influenced his drive toward professional excellence. Such things bring teachers quiet tears of joy.


Dimension Four: Reflective practice and life-long learning to improve teaching and student
learning.
The narrative for Dimension Four should be no more than two pages.

4a. Discuss the more successful and less successful aspects of the instructional activities shown
in the video and discussed in the narrative, and describe what you might do differently to
improve student learning.

The lesson’s greatest impact comes when students create a simulated atmosphere in the

“skinny fish tanks” [Video 32:55]. They can see the spatial sequence of color scattering, which

not only accounts for the blue daytime sky, but also the orange-red skies of sunrise and sunset. A

shortcoming of the lesson is that it is heavy on teacher-talk and content delivery. The animated

graphics of the presentation help in this regard. I must confess to running the lesson a bit faster

than my usual pace out of awareness of the video camera. Modifications for future use would

likely include slowing down. An extension question could be added: What if infrared, not

ultraviolet, were scattered best in the atmosphere, but our eyes maintained their current

sensitivity? (The sky would be orange.) I should research the visual sensitivities of animals to

learn more about how they might perceive the color of the sky; students wanted to know this.

4b. Describe how reflection on your teaching practices helps you improve your classroom
instruction. You may provide examples of lessons or activities you revised based on this
reflection.

My curriculum consists of materials of my own making. While curriculum creation

requires a significant investment of time and energy, it also allows me to easily modify materials

when needed. This flexibility is useful in improving laboratory activity instructions. While I

might think my instructions are perfectly simple and clear in the first operational document I

produce, I often find students bog down or take a wrong turn somewhere. Modifying the

document electronically while the problem is fresh in my mind ensures next year’s students will

have a smoother experience.


Sometimes a classroom discussion will follow a tangent that is, in fact, a valuable

application or extension of the lesson at hand. Again, simple modification of the document

ensures that we will wander off on that fruitful tangent again next year.

Some lessons end in frustration for students and instructor alike. Assuming the content in

question cannot be removed from the course, it becomes critical to revise the lesson. It is often a

matter of breaking the subject down into smaller, more manageable steps of content acquisition.

Sometimes an approach must be abandoned in favor of a new one. For example, incorporation of

a computer simulation (such as those offered free of charge from the University of Colorado’s

PhET program) can draw students into an otherwise daunting topic.

4c. Using one or two of the professional development experiences cited in your résumé, describe
how your participation in these activities has improved your teaching and enhanced student
learning.

I attended my first American Association of Physics Teachers national meeting in June,

1989. There I attended workshops led by Jim Minstrell (Mercer Island High School) and Dewey

Dykstra (Boise State University). Their sessions opened my young eyes to a more constructivist

and inquiry-based approach to classroom instruction and laboratory activities. Their impact was

significant: I have incorporated those approaches in the curriculum materials I have written since

then.

While leading a Physics Teacher SOS workshop this year on heat, sound, and waves, one

of the participants mentioned the idea of constructing a wave machine out of gelatin candies. I

subsequently researched the design, modified it, and assembled the materials to try it with my

own students. They loved it! And they did learn something about wave mechanics along the way.

Having seen some online videos of various attempts, I created one to add to the mix. Since I

chose Dots as the gelatin candy, my lab and video are called “Connecting the Dots.”


Dimension Five: Leadership in education outside the classroom.

The narrative for Dimension Five should be no more than two pages.

5a. Describe how you have supported other teachers, student teachers or interns through
activities such as induction, mentoring, leading professional development activities, or co-
teaching.

I support California physics teachers through the Physics Teacher SOS workshops

sponsored by the Northern California and Nevada American Association of Physics Teachers

(NCNAAPT). For over a decade, PAEMST honoree, Paul Robinson, and I have led day-long

workshops sharing wisdom earned over our years of experience. We start with a rough outline,

but allow our participants to direct the discourse where possible. We show demonstrations and

discuss presentation techniques. Guidance is provided on scope and sequence, standards and

assessment, equipment acquisition and management, and any other area that weighs on our

participants’ minds. We give participants as much useful curriculum and apparatus as possible.

Participants get laboratory manuals, green lasers, hand-crank generators, ball and ring sets,

constant velocity cars, flying pigs, rainbow glasses, and much, much more. We also give specific

instruction on how best to use each item in our “goodie bags.” Mostly we try to convey our

excitement for teaching physics. Robinson and I (and our hundreds of happy participants) agree

that these “agenda-free” workshops are more valuable than most professional development

opportunities for physics teachers.

This past year, I spun off part of what we do as a workshop for the AAPT’s Summer

Meeting in Portland, Oregon. There, I was able to share ideas on what physics teachers can do on

the first day of school, Back-to-School Night, and Open House. Open House is an opportunity to

turn the classroom into a miniature hands-on science museum. The first day of school and Back-

to-School Night can be designed around an idea I learned from Cal Poly Pomona professor and


author, John Jewett: “Physics Begins With an M: Mystery, Magic, and Myth.” The

corresponding presentation stirs curiosity by posing questions (such as “Why is there air?” and

“Why is the sky blue?”), demonstrating strange things (like Lenz’s Law or Pepper’s Ghost), and

calling out myths (such as “Rubber tires protect occupants if a car is struck by lightning”). All

without explanation. Some students express frustration from all the questions posed yet not

answered. It is an engaging way to begin the year and each unit throughout the year.

5b. Describe how you contribute to educational excellence at the school, district, state, or
national level.

My students routinely give me high marks for my presentations, so I gave a workshop at

my school showing teachers good and bad PowerPoint techniques. When my district was

adopting state standards, I led a team that developed a series of high-quality, standards-aligned

test questions. As a member of the state’s Assessment Review Panel, I evaluate potential state

test questions for validity and alignment to state standards. I argue vigorously in favor of

questions I find valuable and against questions I find fault with, all in the hope of best serving

California. I served a similar role on the AAPT’s Examinations Editorial Board, although that

body also developed test items. I present important issues to my colleagues in the NCNAAPT in

hopes of informing and inspiring conversations. My most widely known and valued

contributions come through the extensive curricular and extra-curricular resources I have created

and made available at my website, www.phyz.org. In addition to physics content, worksheets,

demonstrations, video questions, and labs covering our two-year physics and AP Physics

program, I have links to my Blog of Phyz, Web Video for the Classroom (“YouTube Physics”),

Skepticism in the Classroom, High-Speed Video Clips, and much more. I find it rewarding to

create and share the resources, and it is rare for a week go by in which I do not receive a

thoughtful thank-you note via email from someone somewhere [Supplemental Page 7].


Sample Dimensions Essay: Dean Baird

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