The Touchstone Experience

“Science is not just a body of knowledge that reflects current understanding of the world; it is also a set of practices used to establish, extend, and refine that knowledge.  Both elements-knowledge and practice-are essential.”

National Research Council, NAP 2012. A Framework for K12 Science Education: Practices, Cross-Cutting Concepts and Core Ideas.

With the shift from a content-centered classroom emphasizing the “what” to a classroom where core ideas and practices emphasizing the “how” carry equal weight, the scaffolding of thinking skills becomes a critical element of student success.  Since my partnership in the classroom is focused on helping students develop these skills, my next blog entries will chronicle our journey in the creation of student “thinking products”.  My goal is to explain the reasons behind the instructional decisions I am making to engineer experiences in the classroom to facilitate student critical and creative thinking leading to deep understanding of core ideas.  

 The Touchstone Experience

“Touchstone Experiences” are defined by educators in many ways.  In my classroom these are experiences meant to engage the student, serve as an initial access point for both content and process skills, allow for individual student reflection, and serve as a concrete foundation on which new knowledge and skills can be constructed by the student.  These “touchstone experiences” are not the student “thinking products”, but an important foundation activity for both the thinking around science and the content that will eventually culminate in the “thinking product”.

Here is an illustration:

 The Bean Model

At the beginning of a unit on the urinary system, I provided each student group of three with the following materials:  large plastic colander (holes big enough for rice to pass through but not blood cells),  flexible bowl (you can bend in the sides to easily pour contents in the bowl into a smaller diameter vessel like a cup), a quart size plastic Ziploc storage container with lid filled with red kidney beans –red blood cells(70%), white lima beans–white blood cells (20% ) and brown and white rice–creatinine and urea, waste products in the blood (10%), a clear plastic cup (to catch the “urine containing waste products”), a stopwatch

I gave these directions:  This is a quart of blood.  Your task is find the “best” way to remove the white and brown rice from the blood as fast as possible using all the materials provided and put the rice in the plastic cup.  Please record your different approaches and time for each trial.

Students work through this quick and easy model of kidney filtration followed by a class discussion about the function of the urinary system, the function of the kidney specifically, and the components of blood, and then individual student reflection about how the model connects to the main points of the class discussion. Although in itself, the activity is simple and straightforward, how the teacher uses the “touchstone” as students progress through the unit is where the facilitation of critical thinking begins.

This “touchstone experience” meets my needs as an educator for three reasons:

  • It is simple and straightforward
  • It engages students
  • It serves as a foundation or common reference point for more complex learning and thinking

This activity models one of the jobs of the kidney:  filtration.  As students learn and are asked to think about other aspects of kidney function (reabsorption, blood pressure regulation, water balance, hormone influence at renal level, diabetes), the “touchstone experience” is a foundation for understanding those more complex ideas and connections.  I layer these other experiences/discussions throughout the semester as we connect the urinary system function to other body systems.  It may have been two months since the touchstone experience, but during a discussion of a more complex idea, all I have to do is shake my hands in the air like I’m grasping that imaginary colander, and the student’s face lights up with a plan to tackle the more complex problem.  They have made a connection to that common reference or touchstone and are using it in their thinking to approach the new problem.  

I am finding that when I intentionally plan a “touchstone experience” that meets my three specifications for each unit, students are able to do more complex thinking and learn core ideas in greater depth because I am giving them a foundation in the “thinking scaffold” or a foundation to scaffold new knowledge that they themselves are engaged in making. Using these touchstones, students can connect new information in a meaningful way to their own experience and thus enable the student to reach higher cognitive levels of both content and thinking.  

 A few weeks ago @wmchamberlain (who I learn from often) tweeted about the need to share the thinking behind our instructional decisions in the classroom so we can all improve our practice.  Common to my previous experiences on Twitter, I was inspired by his call to action.   As educators, we understand “what” to teach, I have been inspired by learning from others in my PLN (Professional Learning Network) discussing and reflecting on “how” to teach students in today’s standards climate, with today’s technology, and especially with today’s students. I hope this entry and the entries to come will help others understand my “how” as I have moved from a content-centered classroom to a space of shared thinking and learning through science.


I would love to hear about how you create learning experiences for your students.  What instructional decisions do you make and why do you make them? What does a touchstone experience look like in other subject areas?

Please share by commenting or tweeting to @tdishelton.


Activity adapted from “Race for the Pure”/ UT Health Science Center