Tag Archives: pedagogy

Updated Physical Representations of Variables, Objects, and References in APCSA

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I’ve been meaning to update my post from 2018 – Physical Representations of Variables, Objects, and References in APCSA with how it has evolved the past two years. The impetus to finally do so is due to attending Colleen Lewis and Hannah McDowell’s CSTA 2020 session, “AP CS A: Physical Models of Java Memory”. Colleen has a document with instructions, examples, videos, everything. What I realized during the session is that my approach was missing the concrete representation; it only had the pictorial and abstract representations. (I love the use of “remote controls” to model references!) So, I’m off to buy materials (I hope I can find stuffed animals that are turtles) and add concrete representations this year. I still want to share some updates on my pictorial models that have evolved over the past two years.

The most important change has been how invoking methods are modeled. I’ve captured this pictorial model in a set of slides (slide 22 – 34). These slides capture the following examples of invoking a method:

In the classroom, white rectangles still map to full sheets of paper (objects) and yellow rectangles still map to sticky notes (variables), as described in my original post. The new addition is the green rectangle, which maps to a green half-sheet of paper in the classroom that is presented as a form that is filled out, turned in, and returned when a method is invoked. The form models a method invocation. There are some parts of the form (arguments) that must be completed before the form is turned in (method is invoked). The field “this” must be completed (for non-static methods). When filling in the form, values are always copied from sticky notes (variables) or literals. There may be a part of the form that is “for office use only”. That is, it is not completed when initially filling out the form but will be completed when the form is returned. This models the return value of the method. When the form is returned, this value is copied from the form to a sticky note.

In class, students create these pictorial representations for various examples to develop their understanding. This additional pictorial representation coupled with improvements based on comments on the original post and feedback from students, has resulted in a model that helps students develop a strong understanding of, what I believe is the most challenging concept in APCSA, references in Java. This year, I’ll demonstrate with the concrete representation and then have students create these pictorial representations.

Three Realizations about SBAR (Start of Year 1 vs. Year 2)

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Now six weeks into the school year, I’m reflecting on how standards-based assessment and reporting (SBAR) is impacting my students and colleagues this year compared to last. There are a number of significant changes. Last year, my colleague and I were two of only a handful of teachers who were implementing SBAR into their classes. Last year, I only integrated SBAR into my honors physics class and not my regular physics class. Last year, I used SnapGrades to report learning progress to students and parents. Last year, I jumped aboard the SBAR Express with both feet. Last year, I was a neophyte. ***Last year was the best year ever.***

The most important realization is that ***standards-based assessment and reporting is a philosophical change*** made by teachers, students, parents, and administrators. It is not simply a function mapping a traditional grading scale to another set of numbers and symbols. If any participant; teacher, student, parent, or administrator; fails to realize this, the benefits of SBAR will not be realized. Even worse, the SBAR movement will suffer as misguided or half-hearted efforts labeled “SBAR” fail to improve learning. If the teacher doesn’t make this philosophical jump, there is no hope that students or parents will. An administrator recently shared with me that the term Standards-Based Grading was a bit of a misnomer since grading is only a small part of what SBG encompasses. I shared the Standards-Based Assessment and Reporting term (which you’ll notice I’m using exclusively in this post) as a more apt alternative. Last year, my colleague and I did not set out to implement SBG or SBAR or any other acronym. Rather, we set out to change students’ perspectives on their learning and the role of grades in our class. SBAR was simply a tool that helped us achieve these goals. As more and more teachers and teams integrate SBAR practices into their classes, I’m very worried that they see SBAR as the end goal as opposed to the means to much more important ones.

The second key realization is that ***clearly presenting the rationale behind SBAR to my students is critical***. Last year, I made a very conscious and deliberative effort to explain SBAR, it purpose, and my rationale for integrating it into our class. My colleague and I received feedback that our students had a very clear understanding of SBAR in our class and our rationale for integrating it. I expect that I haven’t made enough of an effort this year to communicate the rationale. While I may be more familiar and comfortable with SBAR, many of my students are not. Until this year, I didn’t fully appreciate that the manner in which grades are reported to students and parents affects my ability to change students’ attitudes about learning and grades. Last year we reported learning progress with [SnapGrades](http://snapgrades.net/). The “report card” had no percentages and no letter grades. Just a list of standards and a note of which the student had demonstrated mastery:

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This year, SnapGrades is not an option and we’re using our aging and soon-to-be-replaced online grade book. When students are parents look online, they don’t see any description of standards or clear indication of mastery. They see misleading percentages and letter grades:

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How can students focus on developing their understanding when they are confronted with “0% (F)” and a “C” in bold, red type? This year, I’m fielding more questions from students and parents about improving their “grade” as opposed to their understanding. I have taken some steps to mitigate the negative impact of our online grade book and will be doing more shortly. More importantly, now that we’ve been together for six weeks, its time to discuss the rationale for SBAR again in each class.

The third realization is that ***taking small steps to integrate SBAR is actually harder and less effective than jumping aboard with both feet***. In my regular physics class, my team agreed to a more conservative approach. We are not measuring student understanding in terms of “mastery” and “developing mastery.” Instead we are using a 1-4 grading scale. The challenge with a 1-4 scale is that students and parents (and some teachers) see it as points or A, B, C, and D. I know that many students see a “2” and think, “that’s a C” rather than “there’s a major concept here that I don’t yet understand.” I’ve had multiple conversations with students who ask why if they only missed one part on an assessment they have a “2.” They are thinking in terms of percentage of questions answered correctly and not that they failed to demonstrate a major concept that is essential to understanding. In order to help students breakaway from their grade-centric mentality, I have to create as large as possible disconnect between symbols used to provide feedback and grades. Since I don’t see the 1-4 grading scale going away in the future (and actually fear it becoming required), I need to work extra hard in class to tie my feedback to their learning and not to their grade.

Despite the challenges that I’m facing, I want to be clear that I’m pleased and hopeful about where we’re heading this year. The best indication that I’m on the right track is that ***I can’t imagine going back to teaching my regular physics class like I did last year***.

This reflection has helped me realize how much work I have to do this year if I want it to be as successful as last year. If you are new to SBAR, hopefully my perspective of two years of introducing SBAR to my classes will help make your efforts more productive. If you have any suggestions, please do leave a comment!