“Cooking Show” CS Lessons / Presentations

What do you do if there isn’t quite enough time in a CS lesson or a CS conference session? What “cuts” do you make and why? What do you focus on and/or highlight? What do you downplay and/or skip? Would your decisions be different if the activity was for new-to-CS learners or experienced CS learners?

This is a dilemma Toni and I have faced on a number of occasions. One approach that we have found particularly helpful for these situations is what we call “Cooking Show CS”.

Consider a cooking show for a minute… Time is not spent equally on each part of the cooking experience. Rather, some parts—the really important parts—are slowed down and discussed and modeled in great detail. Other parts—the not-so-important parts—are sped up considerably or even skipped entirely. Like, seriously, when does a cooking show include “real-time footage” of a recipe baking second-by-second in the oven?? We don’t need to see that—we get it. We often do need to see the preparation and the active cooking and the tips and tricks and the cooking “theory” being applied to this particular recipe. So that’s where a cooking show spends its time.

What would the CS equivalent of this be? What would it look like for a CS “recipe”/program/project to slow down and focus deeply on the preparation and the active computational thinking and the tips and tricks and the computer science theory…while speeding up or skipping entirely the parts that we don’t need to see or do in their entirety?

Here are two vignettes of how Toni and I have tried to used “Cooking Show CS” in 1 hour conference sessions.

Side Note: We don’t think that this pedagogy is always effective or that it is necessarily the best approach in all instances. Rather, we contend that there are times (i.e. short conference sessions) where it might meet a need—allowing participants to “develop” (or co-develop) a program in one hour that otherwise might take them much longer.

Guess My Number

In this particular session, new-to-CS learners were learning about introductory CS control structures, including sequential, branching, and iterative pathways. Participant pairs worked together to make sense of block-based pseudocode for this particular program, then we collectively translated this pseudocode into the text-based language of the TI-84+CE (by hand — more on that decision later). (Toni or I will share more about the block-based pseudocode we used for this activity in a later post.)

We ended up with the following program coded by hand on paper:

:Disp “GUESS IS TOO HIGH”
:Wait 0.5
:Send(“SET SOUND 1046.5 TIME 0.5”)
:Wait 0.6
:
:Disp “GUESS IS TOO LOW”
:Wait 0.5
:Send(“SET SOUND 65.41 TIME 0.5”)
:Wait 0.6
:
:randInt(1,20)→N
:
:Input “GUESS? “,G
:
:While N≠G
:
:If G<N
:Then
:Send(“SET SOUND 65.41 TIME 0.5”)
:Wait 0.6
:
:Else
:Send(“SET SOUND 1046.5 TIME 0.5”)
:Wait 0.6
:End
:
:Input “GUESS? ”,G
:
:End
:
:Disp “YOU WIN!”

Getting to this point took time, as we carefully constructed, deconstructed, and discussed the various computer science principles at play in our program. How were we possibly going to have time to code this program into the calculators, as well?

Here’s where “Cooking Show CS” came into play.

Toni and I created a partially pre-made version of the program (called NUMGAME) and uploaded it onto all of the handhelds in the room. Instead of starting from scratch, participants opened up NUMGAME to find the first 9 lines of code already coded into the program—specifically, the lines highlighted below:

We helped participants navigate through entering the remaining lines of code into the “pre-prepped” program. Most participants finished coding these commands into their handhelds in time to test and run their programs, but a few did not.

We had considered this possibility, so we also preloaded a program called NUMGAME2 onto all of the handheld calculators. This program included all of the lines of code we (as a group) had collectively coded by hand.

This, to us, was akin to the moment in a cooking show where the chef puts a “raw” dish in the oven, but then a few minutes later pulls out a “finished” dish that had already been cooking for the full amount of time. Our choice here was purposeful: We wanted all participants to experience success with the program that they had helped write, even if they didn’t have time to “type in” each line of the code.

We included two additional “pre-cooked” programs for participants to consider, as well—NUMGAME3, which added in additional context for the user, visual (LED) outputs, and a celebratory tone when the user guessed the correct number; and, NUMGAME4, which abstracted the program so the user determined the upper bound on the range of possible numbers and also included a counter that tracked and displayed the number of guesses the user needed to guess the number. Participants were given a few minutes to run each of these programs and then predict what the changes in the code might look like in order to result in these “enhanced” versions of the program.

Respect the Beep

Toni has written here about the “Respect the Beep” session we have led where we use the TI-Innovator and the Ultrasonic Ranger to model a vehicle’s back-up sensor. I discussed this same program (but through a pedagogical lens) in this post about Introducing CS with Flowcharts.

When we led this activity in a conference session earlier this summer, we had a sequence of three programs we were planning to write as a collective group.

Here is the finished code that we wanted to arrive at for the first program:

Toni and I decided to create and provide participants with a pre-made file with the following parts of the program already “cooked”:

Including these commands allowed us to: save a few minutes of coding time in the conference session; and, focus primarily on the theory and syntax of sending and receiving commands from the Ranger, rather than just the digital connections.

Wrapping a While loop around the data collection part of this program doesn’t take a lot of extra time, so that’s something we had participants do themselves, as well, resulting in a program of:

P.S. Highlighting text using the Shift button and then inserting a While…EndWhile loop from the Menu will insert the While loop around the highlighted text. Here’s a little GIF showing this tip:

 

However, we did run out of time for participants to code in the final branching structures that were to be housed inside the While loop. Here was our end goal:

How might we have used another “Cooking Show CS” program here to help us meet our instructional goal in the short amount of time we had with these learners? Toni and I have considered using an “almost done” version of the file that looks like this:

where participants would fill in the output commands (represented above by the highlighted blank lines) within the various branches of the program.

What are your thoughts? How might using a “cooking show” approach for a CS lesson/activity/presentation allow us to focus more on our CS instructional goal and less on aspects that participants perhaps don’t need to see or do in their entirety?

Introducing CS with Flowcharts

Toni and I have spent a lot of time over the past year thinking about pedagogical approaches that are effective for introducing CS topics to learners who are new to CS. Also, we’ve thought a lot about how to do this within relatively short learning episodes, such as a 60-minute conference presentation.

Our goal for the end of a 60-minute conference presentation is usually to have participants code out (on a calculator and also (usually) by hand) a rather complicated program — but, more importantly, to have made sense of said program.

In a recent conference session, our goal was for participants to code a program that modeled a back-up sensor on a car, complete with audio feedback based on how far the “car” was away from an object. This particular program (see Toni’s post here for more information) included sequential, branching, and iterative elements, as well as commands related to connecting to, collecting data from, and disconnecting from an actuator (or peripheral device). These are a lot of different elements for someone who is new to CS to integrate!

How might we design learning experiences to support sense-making around these varied commands/structures…in a way that is accessible for new-to-CS learners?

One approach that we have found particularly effective for this work is using flowcharts — specifically, using flowcharts that develop over time. Rather than just jumping right into this rather complicated flowchart (again, complicated for a new-to-CS learner!):

we instead provided the following blank flowchart and had participant pairs brainstorm what commands might need to go into this flowchart (and in what order) in order to read and display a distance measurement from an Ultrasonic Ranger attached to the Innovator.

Note that the task of collecting and displaying a distance measurement is not our end goal, which is to model a back-up sensor — but we deliberately wanted to decompose this program/situation into simpler situations first. In this case, before we model a full-on sensor, how might we code the Innovator just to collect and display a data measurement?

A quick debrief of ideas from the whole group (plus some information from us on what these commands look like for the Innovator) led to this filled-in flowchart:

With a completed flowchart, we quickly “translated” the pseudocode in this flowchart into the programming language of the TI-Nspire and TI-Innovator. Participants checked that their programs collected and displayed a valid distance measurement as intended.

Next, we asked participants to consider, What if we wanted to collect data measurements repeatedly, instead of just once? We provided the following blank flowchart and had participant pairs consider what commands might go in each element of the flowchart.

Participants talked through lots of important ideas here, including: What should go in the “decision diamond”? What commands should happen “outside” of the loop structure? What commands should happen again and again (i.e. inside the loop structure)?

Debriefing these ideas whole-group led to the following completed flowchart:

We quickly coded these additional commands/structures into the program we had started earlier and tested our new programs.

Now, our program collected distance measurements again and again until the distance was less than 0.01 meters. For the sake of our model, we said that this value represented the back-up sensor turning off after a collision — whoops! 🙂

However, our sensor wasn’t giving us very helpful feedback! It was displaying the distances, but who would be reading that display while backing up?! We wanted to add in audio feedback (beeps!) that alerted us if we were nearing an obstacle. Specifically, we wanted there to be two “levels” of audio feedback — warning beeps if we were nearing an object, but then a more urgent set of warning beeps when we got really close to an object.

We provided the following flowchart for participant pairs to discuss:

which led to a final debrief and this filled-in flowchart:

Here we were, finally, at our programmatic goal! We had collectively developed a program (in flowchart form and in coded form in our calculators) that modelled a back-up sensor.

Yes, it took a while to get there, but the time spent sense-making about the earlier situations and flowcharts helped participants develop and use appropriate CS structures and logic while creating this more complex program. We were thrilled with the engagement, discussions, and explanations from our participants, many of whom were new-to-CS learners!

Side Note: When leading this conference session, we ran out of time during the calculator coding of the final part of the program. 😦 We have discussed some time solutions for this for future presentations of this conference session including having participants code the first program on the calculator, but providing “almost complete” versions of parts 2 and 3 already on the calculator. This will cut time out of the session without losing any of the time that focuses on sense-making about the code.

To create these flowcharts we used the LucidCharts Diagrams Chrome extension, which allowed us to create and store these flowcharts in GoogleDrive.

Here’s a copy of our handout from the conference session; we wanted participants to leave with copies of the completed flowcharts so that they could later replicate this work on their own devices.

How else have you used flowcharts to introduce CS topics to new-to-CS learners? What other pedagogical or instructional approaches have been effective for making CS accessible to all?

Michelle Signature

Guest Post by Toni Norrell | Back-Up Sensor using the Ultrasonic Ranger

Another fantastic post from Toni Norrell (@ToniNorrell).

A friend of mine I’ll call Sandy drives a very fancy car! Her car has all the bells and whistles you might say. It has cameras/sensors all the way around that beep a lot. She has a tendency to ignore them when pulling in and out of parking spots because they beep when she is too close to the curb, they beep at the cars parked on either side, they beep if a car drives behind the car, etc. This particular day she ignored the beeps and backed right into a parked car! Like any good friend would, I made her a pillow that says “Respect the Beep.”

Michelle & I started thinking about how this incident could be modeled using the Ultrasonic Ranger & Innovator Hub. We wanted to write a program that was similar to a back-up sensor on a car. This expands upon my previous post about first collecting distance data from the ultrasonic ranger.

  

The program connects the ranger and uses the warm-up program that Michelle talked about in a previous post. The distance variable is initialized and a while loop is setup to read, get, and display the distance as long as it is more than .01 meters.

The If Then looks at distances between 0.1 and 0.5 and sets the hub to send a sound with a particular frequency if the ranger is within that distance.

When the “car” gets closer than 0.1, a higher frequency sound is heard.

We set both of these sounds inside For loops to provide more of the “pulse-like beeping” you often hear from a car’s back-up sensor.

Here is a copy of the complete TNS file for you to try! Also, here’s a short video clip of this program in action:

What other ways could this program have been written?
How could it run even more like a back-up sensor on a car?

Toni Signature

Warm-Up Program for Ranger (with TI-Innovator)

When the Ultrasonic Ranger is first used with the TI-Innovator (or used for the first time in awhile) its first few data measurements might be erroneous. (Toni discussed how to setup and code the Ranger to collect data measurements in this post.)

TI has created a document that outlines a short code segment that can be included in Ranger programs to allow the Ranger to “warm-up” and move through any possible erroneous data measurements. Here is some sample code for this “warm-up”:

Send “CONNECT RANGER 1 TO IN 1 ”

© Use While loop to “warm up” Ranger

d:=−1

While d=−1

Send “READ RANGER 1”

Get d

EndWhile

As Toni explained in this post, the Send “CONNECT RANGER 1 TO IN 1” line of code digitally connects the Ranger to the Innovator–naming the Ranger (in this case, RANGER 1) and telling the Innovator what port the Ranger is connected to (in this case, IN 1).

The While loop (with an initial value of d:=-1 so that the loop will be entered and will run at least once) acts as a “warm-up loop” of sorts that continues to collect and recollect distance measurements (READ from the Ranger and then stored to d) until the distance measurements coming back from the Ranger are positive distances.

Question: Should the code for this “warm-up loop” be explicitly included in all Ranger programs?

This is something Toni and I were thinking about recently when we were planning a 1 hour conference session that explored using the Ranger. We knew that the warm-up loop was an important segment of code to include — otherwise participants might see and be confused by “measured distances” of -1. However, we didn’t want participants–many of whom were completely new to Computer Science–to have to parse out this section of code as well as the rest of the program they would write. The “warm-up loop” was not the focus of our session, but seemed to be a necessary precursor–necessary to run in order to get accurate data; not necessary for participants to have to decipher (at this point).

Toni and I made the decision to write the warm-up block of code in as another program in the file and then call that program within the real program that we were building in the conference session. Here are two screenshots to illustrate the point:

Notice how the backup_sensor program (the program we were building and learning about in the conference session) was sent to participants pre-loaded with three “lines” of code — a line CONNECTing the Ranger, a method call for the warm-up program, and (later) a line DISCONNECTing the Ranger. The blank lines were for inserting the lines of code we developed as a group to code/model a back-up sensor (more on that in a later post).

One of the advantages of this approach? We didn’t lose time analyzing and reasoning through the While “warm-up loop”, but we still gained the benefit of having this warm-up loop running inside our program. This allowed us (as a group) to focus on the coding segments that were particularly relevant to our instructional goal.

One of the disadvantages of this approach? There was less transparency regarding what role the warm-up program was playing–how it worked, why it worked, why it was necessary, etc.. Also, since participants were not coding on their individual calculators, they didn’t leave with a copy of the warm-up program/code in case they wanted to use it later. One solution to this might be to distribute a copy of the document created by TI at the end of the session.

What do you think? What are the pros and cons of making the warm-up program explicit and/or “hiding” it instead? When might you make this code segment explicit? When might you “hide” it?

Michelle Signature

Guest Post by Toni Norrell | Getting Started with the Ultrasonic Ranger (with the Innovator Hub)

A great post from Math & Computer Science guru Toni Norrell (@ToniNorrell).

Michelle & I wanted to explore using the Ultrasonic Ranger with the Innovator Hub for a presentation we were putting together. We started off by focusing on the syntax needed to connect the ranger to collect a distance measurement. This consisted of several lines of code in the screenshot shown below.

Send “CONNECT RANGER 1 TO IN 1” is the initial code that connects the ranger (named RANGER 1) to the hub digitally. Physically, the ranger is connected in the port IN 1 on the side of the Innovator hub. The commands Send “CONNECT RANGER are found under the hub menu (Send “CONNECT -Input), TO is found in the hub menu under settings, and IN 1 is found under the hub menu and Ports.

Once the ranger is connected, we want to send a command to read this device called RANGER 1 using the command Send “READ RANGER 1” . The “READ” command tells the Ranger to “read” the distance at that particular instance in time. So far, we have connected the ranger, and read the ranger, but we haven’t done anything with that reading. Our next statement Get distance, will actually get the reading and then store it in a variable named distance. Of course, we won’t see this value unless we use the display command to show us the output: Disp distance. Note: The display command is not necessary for the data collection to work, however, it is a nice feature that allows us to get that visual check to see if our program is recording and saving distances.

It is good practice to use the last line of code which is Send “DISCONNECT RANGER 1” which is found under the hub menu. On the next post, Michelle will address the warm_up() statement in the code.

Here’s a short video showing this program in action. Also, you can download a copy of the TNS file for this short program.

Toni Signature