I saw this tool in Texas at CSTA and loved playing around with it so I was really looking forward to teaching this lesson. I had a lot of thoughts on this lesson and am sharing all of them - hopefully the bullets make it a bit more skim-able for everyone.
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The video did a great job of visually explaining the idea of compression and connecting it to the exploration we have done with bits. I think a good “assessment” question might also be “Is the compression you did lossless or lossy compression” just to bring that idea back.
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Students loved the tool and many students quickly went into adding their own text. That led to a good conversation around what types of songs would be easier to compress than others. A lot of students were doing rap songs, but then decided pop songs would be easier. One student knew of a song that repeated the same words over and over and tried doing that. You might want to tell students to pick appropriate songs - I was worried the tech police would come into my room saying a student was typing inappropriate words on the computer.
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Students got so into it that I had trouble re-focusing them on the activity guide - I could have, but they were discovering so much on their own that I did not find the activity guide necessary.
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The best student-generated questions centered on “why does the compression go down when I ____?” That led to a good conversation around looking at the bits in the text vs in the bits in the dictionary. I probably should have brought that up to the whole class since it was a really good point.
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It might be cool to know the “Best” compression rate for 1-2 to see if students could reach it. I think you could discuss that with these simple poems it is possible to calculate the best compression rate but real files are too big to calculate the best compression. Is that accurate - my content knowledge on compression is pretty slim, but it seems like with the Aaaa… one you could calculate the best compression rate.
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Two students got the same compression rate (exactly) but with a different dictionary which brought up a good conversation about how the compression rate is actually being generated.
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One of my students went into the HTML code to change his “compression” to 100% which angered and confused some students… and then they realized that would be impossible and called him out on it. Had I not seen him in the HTML code, I probably would have been confused as well.
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I somewhat wonder if this could be a two day lesson (or if it is planned to come back to this Widget later). Students loved it and it seems like there was more I could have done as a class after the students were done exploring. Maybe doing a half day of exploration after doing the bits/bytes conversation (which felt unnecessarily long to me) would have worked well since then they could have explored a bit and been ready for a more structured exploration the next day.
This was a fantastic tool and my students loved using it - it really made compression come to life for my students (and myself).