It's (All) About Data

Lab: it's all about data. From beginning to end, the focus is in one manner or another on data. Scientists begin with a question that they hope to answer. And from then on, the focus is on data. And our physics students should participate in the same type of data-centered activities as those of scientists.  Here is a sampling of the type of data-centered activities which characterize most labs.

• Deciding on what data to collect. 
• Deciding how to gather the data. 
• Collecting the data. 
• Deciding how to record data. 
• Recording the data. 
• Determining what the data mean. 
• Determining if the data mean anything at all. 
• Evaluating the trustworthiness of the data. 
• Comparing the data with the data of other experimenters. 
• Comparing data with previous experiments. 
• Graphing the data. 
• Analyzing the data. 
• Presenting the data in various forms.  
• Deciding what forms would be best for presenting the data. 
• Drawing conclusions based on the data. 
• Collecting better data. 
• Deciding what new data to collect. 
• Deciding on better methods of collecting the data. 
• Using the data as evidence. 
• Referring to the data in support of conclusions.

Clearly labs are data-centered activities - activities in which a wealth of decisions about data must be made in order to pave a logical trail from the question to the answer.

It is at this point that science is distinctly different than the other disciplines which our students study. In many of the other disciplines, opinions prevail.  In science, data prevails (or at least should prevail).  As we all know, there is not a lot of room in science for opinion.  Scientists follow the data towards their logical conclusions and make every effort to build models which both assimilate the data and explain the data. In science classes, our students should be doing the same types of activities. They should be given an abundance of opportunities to collect, analyze, evaluate, and draw conclusions from the data.  When it comes to labs, its all about data.

An article titled Using Levels of Inquiry in the Science Classroom, written by Jeff Rylander, was posted previously on this blog. In his article, Jeff provided a framework for thinking about scientific inquiry lab activities.  The framework centered around the division of a lab task into the formulation of a testable question, the development of a method or procedure for answering the question, and the formulation of a solution or answer to the question.  In the framework presented by Jeff, higher levels of inquiry are characterized by activities in which students have a greater degree of control in the various stages of the lab task.  (Jeff's ideas regarding levels of inquiry originated from an article published in The Science Teacher by Michael E. Fay and Stacey Lowery Bretz. The article is available online at NSTA's Science Store.)

When I think about the centrality of data in a physics lab, I think about Jeff's article. Particularly, I think about the locus of control in the various data-oriented decisions which must be made during the course of a lab.  As an instructor, I need to be thinking about what data-related decisions students will be left to make. I need to think about whether I make the decision about what data they collect or whether they decide on what data must be collected.  I need to be thinking about whether I decide on the methods by which students will collect the data or if I will leave that decision to them.  I need to be thinking about whether I decide on how students will organize and present the data or if I will leave them to decide on this matter.  Consistent with Jeff's framework for levels of inquiry, the more the locus of control is shifted from the instructor to the student, the higher the level of inquiry which the lab will assume. And one way to think about scientific inquiry is to think about how many of the data-oriented decisions are being made by the instructor and how many are being made by the student.

As I write this article, I am one day into summer vacation.  School ended yesterday. The summer months allow time to relax and to rest (and to catch up on the honey-do lists), but also time to reflect, rethink and retool. For me, much of my summer reflections will be focused on how I can improve the scientific inquiry skills of my students.  And for starters, I will be thinking about the types of revisions which I can make to the lab program in order to foster improved inquiry skills.  I will be looking at the labs which my students do through the lens of data.  I will be pondering each lab which my students do and asking:  When it comes to data-oriented decisions, where is the locus of control for this particular lab activity? The more that the control lies upon the student side of the equation, the higher the level of scientific inquiry.

In Praise of Projects

In a previous blog, Debbie Berlin wrote about the end of semester projects used in her Regular Physics classes at Glenbrook South High School.  Inspired in part by the design and the success of that project, I decided to implement a similar project in one of my physics courses.  The course is called ChemPhys - a two-year course in which students take chemistry and physics on alternating days, thus completing a full year of chemistry and physics over the course of the two years.  The guidelines, expectations and scoring scheme for the project which I have implemented with my classes are described online at the course site (http://gbschemphys.com/chemphys/lab/project/project.html). In brief, I would describe the project as an open-ended experimental design project in which students attempt to identify and answer a testable question which is of interest to them.  There are few constraints in terms of topic, as long as physics is a naturally intrinsic part of the topic.  As I write, we are currently in the middle of the project, having completed a couple of days of planning and research and three days of experimental investigations.  I am offering in this post what is a sort of mid-term reflection of the progress, joys and frustrations which I have witnessed and experienced.

The most striking observation which I have made thus far is in the level of excitement which students have displayed. The project comes at the end of a two year course and in May - when the northern weather begins to turn bright and sunny and when the students have begun reducing the number of school days remaining to less than 20. This is not exactly a prime time for the display of academic enthusiasm.  Yet there have been several times when I have had to cheerfully pinch myself after being placed in a state of shock by an observation or comment.

The first day of lab research was originally scheduled to begin on Thursday, May 6.  For a variety of reasons I had decided to postpone the start of research until Monday, May 10.  One of the students in my second section of the day entered the classroom looking very dejected and down.  I asked her what was wrong.  She responded about how upset she was that the project had been postponed. She had heard from a friend in a previous section that it would not start until the following week.  She had commented how much she was looking forward to this day and how disappointing that the news was.  I was rather shocked that she was taking what seemed to me to be a very inconsequential decision as a very disappointing turn of events. I began to wonder: When was the last time that the postponement of an in-class activity caused such obvious disappointment on the part of one of my students?  I could not think of such an instance in my 20-plus years of teaching.  Clearly, this student possessed a sense of excitement and anticipation over the start of this research project.

On the third day of our lab research, I entered the room four minutes before class and was instantly struck by what I observed.  Several students had arrived before me and were in the back of the room setting up.  They were fetching their equipment from the various storage locations and preparing to start their research.  As other students entered the room, they set their bags down and headed to the back of the room to do the same.  There was no need for prompting or prodding. They knew what to do and didn't wait for an invitation to do it. With a minute prior to the start of class, one student entered the room, looked around, looked at me, and asked with a sense of amazement "Did the bell ring already?" Given the activity that she observed, she assumed that class must have already started and she had arrived tardy.  I assured her that she was on time, in fact one minute early, but there was no need to wait to begin.  Again, I began to wonder:  When was the last time that my students entered the room and spontaneously began to do science without any prodding or prompting?  Once more, I could not think of such an instance in my 20-plus years of teaching. Clearly, this research project increased the level of engagement of my students in the task of doing science.

A research project of this variety is an assessment.  It is a means of assessing student capability and performance in a manner in which a traditional test is unable to do so.  My tests excel at determining what students know and understand about the concepts and principles of science.  They are able to test students' ability to analyze complex physical situations and to solve physics word problems.  They are capable of determining the proficiency of students at analyzing diagrams and graphs.  But they are unable to test student's ability to conduct an experiment from beginning to end.  One role which this research project plays is that it assesses students' ability to do science: to design an experiment, to determine what data to collect and how to collect it, to analyze the data and draw conclusions, and to determine an effective manner to present the data and results.

As an assessment, a research project of this variety teaches me much which I might not otherwise be aware of.  For instance, it is clear to me that my students have great difficulty identifying a testable question.  During the brainstorming stage of the project, many of my students were able to identify great questions; yet very few of the questions that students initially proposed were testable.  Their questions reflected topics of interest and innate curiosity.  But their questions also reflected tremendous confusion regarding what constitutes a testable question.  Purpose statements such as "to determine what an unsafe speed is in a bobsled race" reveal great curiosity but not much understanding of what can and cannot be done via a high school physics lab experience.  I quickly recognized that the development of a testable question was indeed a challenge for students. I couldn't help but think of a previous article in this blog by Jeff Rylander on Using Levels of Inquiry in the Classroom. In that article, Jeff discussed a hierarchy of four levels of student inquiry which were based upon the work of Fay and Bretz. My research project was challenging students at the highest level - the level in which the question, the procedure and the solution is constructed by the student.

This research project was doing what any good assessment should do - providing the teacher an opportunity to assess student ability and know-how with the intent of affecting curriculum and instruction. Given the difficulties which I have observed, I am already making plans to incorporate more level 4 inquiry challenges into the course.  My goal will be to improve students' ability to construct the question, the procedure and the solution.

My final observation pertains to the dramatic change in my role as teacher.  This research project has truly put me in my rightful place as the guide on the side.  My role is no longer the sage on the stage; rather I am an advisor serving a similar role as a college professor guiding the research of a graduate student.  I suggest things to think about, offer alternative procedures, and direct students to experts in a field or exceptional resources. When the groups encounter difficulties, I become part of their brainstorming team;  together we ponder ideas for circumventing the road-block. I serve as a sounding board for those students who are thinking through what to study, how to study it, how to interpret data, etc.

In addition to being an advisor, I am also a lab equipment manager.  With 16 different projects happening at once, I must make sure that every lab group has what they need when the need it.  This means lots of planning and preparation.  There's no chance for spur of the moment, last-second planning and preparation.  Trips to the local hardware store are common.  These must be planned in advance of the start of the school day.  I certainly can't run out to the hardware store in the middle of class.


I have been pondering the topic of engagement over this past semester.  Exactly what is it that gets students engaged and invested in labwork?  What is that causes students to be excited about the back of the room? What gets students turned on about doing science? I must be honest that I don't know the answer. But one thing that I do know is that an open-ended challenge of this nature seems to maximize student interest and involvement. When students are responsible for the design and development of the entire investigation regarding a topic of their own choosing, the investment level increases. Students become true scientists, engaged in the tasks of scientific inquiry from the development of the question to the answering of the question.  Meanwhile, I am able to observe their work and make judgements about what students can and cannot do as a result of their participation in my course.

This month's article is contributed by Tom Henderson. Tom is the author of The Physics Classroom website.  He is a graduate of the University of Illinois in Champaign-Urbana, Illinois. He has been a high school physics teacher since 1989. Tom currently teaches Honors ChemPhys (Physics portion) and Honors Chemistry at Glenbrook South High School in Glenview, IL, where he has taught since 1989.

Tom invites those teachers who are interested in learning more about his Scientific Investigations website to visit his course pages at http://gbschemphys.com/chemphys/lab/project/project.html.

The End of Semester Project

Ideas for an end-of-semester project

Our second quarter schedule in the Regular Physics course at Glenbrook South includes two weeks after winter break, plus an additional week in January for final exams. For the second year in a row, my colleagues and I have used the last two weeks of the quarter in January for an extensive, lab-based student project with our Physics 163 (middle-level) students. Students are given an open-ended challenge. They must design and run one or more lab investigations that link to several topics we have learned throughout the semester. Students are expected to select complex, measureable lab goals and use a variety of lab equipment in their investigations. Specific directions and the student rubric can be found here. The “pros” of this project are numerous: student interest is peaked by the opportunities for student choice, students connect topics they have learned throughout the quarter, students do thoughtful analysis, students get a taste of what real scientists do, students feel genuine pride at accomplishing a challenging task, and so on. Potential cons include the amount of class time that must be dedicated to the project, the need for laboratory equipment, and the handful of projects that inevitably don’t meet the teacher’s high expectations. I will discuss implementation of the project, state the pros and cons of the project, share a few case studies, and discuss ideas for improving the project and minimizing some of the cons.

Timeline for the project

Prior to introduction: The teachers selected a list of equipment they would provide for students. We then set up the back of the classroom like a “buffet” of equipment. Students would be expected to borrow equipment during the class periods and then return everything to clearly labeled bins in the back. The exceptions were high-theft-risk items such as cameras and electronic balances; students checked these out from the teacher when needed. Teachers also reflected on their desires for the lab and updated the directions (found here) as necessary. The project was scheduled for the last two weeks of second semester. Students had already studied motion in 1-D, forces, 2-D motion and forces, projectiles, momentum, and energy. It was key to do this project at the end of the semester so that students had a range of physics knowledge from which to draw.

The introduction: The project was scheduled for seven class days over a two-week period. On the first day of the project, I handed out the directions and rubric and explained the overall goal. Students were told not to worry if their initial reaction was to feel stumped. Students were encouraged to look back over their lab journal and think about the labs we had done throughout the semester. I also suggested that kids should look at the equipment provided in the back of the classroom. I told students that this was not the only equipment they could use and that they were welcome to ask for additional equipment as needed. On this day and several times throughout the project, students asked for an exact number of labs or topics required. In the past, I told them a minimum number of labs required. This year, I was careful to not give a numerical answer to that question. Rather, I reminded students that their goal was to create a lab (or labs) that is complex, not a repeat of something we’ve already done, and that spans several physics topics. I reinforced that they could do this in one very large and complex lab or with several smaller labs. Students were told that they could pick a partner but that they’d each need to record data and produce their own lab write-up (goal, procedure, data, calculations, and conclusion).

The first few days: The first few days involved a lot of student brainstorming as they tried to pick appropriate goals. When students were stumped, I asked them if they had interests outside of class that they wanted to link to physics. For example, one group was interested in modeling how an airplane takes off from an aircraft carrier. Their project used motion and force sensors to determine the effect of air resistance on a small vehicle. They also linked their goal to work and kinematics. Another group was interested in golf balls. They did a video analysis of their golf swing and also made distance measurements; they then used their data to link work and energy to projectiles and air resistance. I found that I did a lot of listening and suggesting at the beginning of the project. I tried not to squash an excited student’s idea even if it initially seemed too simple. Rather, I encouraged the student to start on that lab and then think about what additional topics they could work into the lab as they did it; I also offered ideas about how they could bring in additional physics topics to their project.

The middle: The middle of the project involved lots of discussions about experimental methods. Frequently, I ran to the prep room behind my classroom to get additional materials. A student modeling collisions with an air bag in a car wanted Ziploc bags; a student connecting energy to projectiles and work done by friction wanted hot wheels tracks and cars; a student launching a projectile into a cup to study projectiles, collisions, and energy wanted cups; students studying friction wanted a variety surfaces made of different materials; students projecting marbles into cars wanted cotton balls. The list goes on. I was lucky to have lots of materials on hand; at the same time, teachers at schools with a smaller variety of materials could simply have students bring in any additional items they wanted to use. I was surprised by how many students chose to use video cameras and analyze the video using the LoggerPro Vernier software. We didn’t use the cameras to do video analysis more than about once a month during the semester. However, students were very comfortable with the cameras. Video footage (or should I say “bitage”—no need to measure feet of tape any more) is a huge part of students’ world and they bring a lot of technical expertise to the table. A large percentage of students also used Vernier probeware such as motion sensors or force probes during their project.

The results: As I am writing this article, I am at the front of the classroom and my students are taking their final exam. In an hour, when the exam ends, they will turn in their journals which include their final project. A few turned in their projects already and I have graded those. The results of student learning will vary from student-to-student. Some students will have learned more about analyzing videos while others may have learned more about analyzing errors in the lab. However, I feel that all students benefited from experiencing what “real science” looks like. The students were invested and excited about their project and did think deeply about the connections between the physics topics. The process itself was valuable. Admittedly, the students did not all learn the same physics content during the project. There is a constant pull between wanting to give the students time to investigate and making sure to cover enough topics. In December, I was wondering if I really wanted to do this project again. I was thinking about how we could spend the two weeks doing another chapter in the book instead. I am so glad I did the project again and remembered how much I value it. Several case studies below show examples of student experimentation. The case studies also illustrate how varied the projects can be. Teachers should be flexible and reasonably comfortable with physics and experimentation so that they can guide their students.

Case Studies

Case study #1:

The image to the right shows a stuffed pig swinging like a pendulum from a rope attached to the classroom ceiling. Why? Because this group was (a) obsessed with the stuffed pig, and (b) attemping to have the pig safely land on the foam on the floor. A razor cut the string when the pig was in the lowest position of its arc. They did a vector analysis of the tension, used energy to predict the velocity at the bottom, and then used projectile equations to determine where the foam should be placed. This was only part of their analysis. Another group did something similar, but they had the pendulum hit a stationary object that then became a projectile. This meant that they were also doing a momentum collision analysis along with energy and projectiles.

Case study #2:

The group with the two photos here set up a projectile launcher at an angle. They found the initial velocity of the launcher and determined where to set a tube (incined plane) to catch the marble. At the bottom of the tube, there was a cart with a cup on it as shown in the picture on the right. They did a work-energy analysis as the marble slowed to a stop in the cart.

Case study #3:

The girl in the movie still-shot at the right is an avid horse-rider. Her goal was to learn about the power involved in a horse’s jump and also to analyze the motion of the horse in the air and see how much of an effect air resistance had on the horse’s motion. She relied on the video-analysis feature of the Vernier software program Logger Pro. As this image shows, I allowed students to check out cameras if they wanted to do a real-world experiment that couldn’t be modeled in the classroom. Students checked out cameras to help them analyze golfing, sledding, driving, and the like.

Ideas for extending the project:

In reflecting on the past two weeks, I feel that there were two big things missing from this project. I would have liked the students to have received written (as opposed to only oral) feedback from me during the project. I would have also liked students to share their projects with the rest of the class. Both of these were accomplished by a co-worker of mine. He had the students present their projects not in a journal but on their class Wiki. Students could see each others’ projects, and my co-worker commented (in red text, of course) on their writing as the project went on.


This month's article is contributed by Debbie Berlin. Debbie is a graduate of Northwestern University in Evanston, Illinois. She has been a high school physics teacher for 11 years. Debbie currently teaches Regular Physics and Honors Physics at Glenbrook South High School in Glenview, IL, where she has taught since 2004.  

Using Levels of Inquiry in the Classroom

If you are a physics teacher, I am sure you have wrestled with the level of inquiry with which you present activities to your students. Should all laboratory experiences in a physics class require a similar level of student inquiry? Do you believe the students in your class have an innate ability to ‘do science’ as scientists, or do you think that you need to develop these skills in them? As you consider these questions, let us look at one class's experience as they investigate the relationship between force, mass, and acceleration.

The Student Experience
On Monday, students enter the physics classroom to find a room full of exploration stations relating to the concept of force. As they make their way from exhibit to exhibit in this hands-on, museum-type experience, they encounter a series of brief tasks they are asked to perform, followed by a thought provoking question at each. For example,


“You notice a fan apparatus that is attached to a cart. After
you turn on the fan and release the cart, carefully observe
the type of motion that results. Let’s assume that the fan
provides a constant force on the cart. What type of motion
occurs when a constant force acts on an object?”



Exploration is an important first step as students encounter new phenomena and new experiences. Although students begin to generate their own set of questions in Monday’s activity, the teacher is the one who asked the initial questions and provided the specific tasks to perform.

On Tuesday, students participate in an interactive demonstration involving a piece of equipment and phenomenon that they had already ‘played with’ the day before. The demonstration is designed to address a common misconception that students have and to give them a chance to share their beliefs concerning the concept at hand. As the teacher and students collect data, make observations, and perform the demonstration, the teacher is careful to ask questions that not only address the misconception but also help students reflect on their thought processes and methodology. “How can we know that a constant force was acting on the cart? How can we measure the fan’s force while the cart is in motion?” Students might discuss their answers with a classmate and then write about not only what they learned but how they know it. Here the teacher has asked the questions and, through guided inquiry, has helped the student think through how these questions might be answered.

On Wednesday, a brief question is posed by the teacher in a context that is relevant for students. As students move to the laboratory, they seek to discover an answer to this question by (1) using equipment that they are familiar with from the past two days, and (2) considering how this equipment might be best used in light of the previous day’s demonstrations. “How does changing the mass of a cart and changing the force on the cart affect its acceleration?” is the question posed. Here the teacher has asked the question, but the students must design their own procedure to answer this question. To the lab they go!

As the week comes to a close, students are now faced with the need to apply in the ‘laboratory’ what they have explored, interacted with, and discovered. They are faced with a challenge, a competition, or a problem. They must apply and evaluate what they have learned—or perhaps create something! As this particular week comes to an end, students are given the class challenge to use their teacher’s car as the object with which they must creatively apply the force-mass-acceleration relationship that they have discovered. They decide to determine the car’s mass by pushing it with a constant force and by determining its acceleration. In this activity, not only did the students design the experiment, they helped form the question to investigate. To the parking lot they go!


Levels of Inquiry
In the article, “Structuring the Level of Inquiry in Your Classroom,” authors Fay and Bretz suggest four levels of inquiry (numbered 0 through 3) as summarized in the table below. One might notice that as the force-mass-acceleration relationship was developed in the activities above, the level of inquiry was increased from level 1 to level 3 as the locus of control shifted from the teacher to the student.

Level	Problem/Question	Procedure/Method	Solution
0	Provided to student	Provided to student	Provided to student
1	Provided to student	Provided to student	Constructed by student
2	Provided to student	Constructed by student	Constructed by student
3	Constructed by student	Constructed by student	Constructed by student

The figure below, adapted from “Levels of Inquiry: Hierarchies of Pedagogical Practices and Inquiry Processes,” illustrates the continuum that was used in the above classroom example.



Although the trajectory of inquiry suggested above—that is, moving from low inquiry to high inquiry—is one of many and is not meant to be a formula for which every concept should necessarily be developed, it has been chosen as a framework that affords students the opportunity to grow in their ability to use inquiry as their level of conceptual understanding and comfort with the equipment at hand deepens. Such a hierarchical inquiry paradigm models Bloom’s taxonomy, provides teachers a framework upon which inquiry activities can be built, and most importantly, works for students.


This month's article is contributed by Jeff Rylander. Jeff is a graduate of Wheaton College in Wheaton, Illinois. He has been a high school physics teacher for 20 years. Jeff is currently the Supervisor of the Science Department at Glenbrook South High School in Glenview, IL, where he has served since 2006. Jeff has been instrumental in encouraging science teachers to implement inquiry-based activities into their science classes and to adopt the use of lab notebooks and lab journals. In addition to his duties as science supervisor, Jeff teaches Regular Physics at Glenbrook South.