'15-'16 Lossy Compression and File Formats


#1

Use this as a space to record your feedback and questions about this lesson.


#2

they are all related to text compression.
I will use most of the provided lesson materials. I will make a few changes
to fit with my students’level of interest.
I will use ECS Unpluged materials as additional resources
I will develiever the lesson similar to what is given here.
I will give my students a TPA task (groupwork, presentation) at the end of the lesson.
Content questions: How might you encode colors? How do you compress text? Can you invent simpler ways to compress text?


#3

I would follow the lesson until I get a feel of how class will react to the assignments and activities. I am sure pace and feel for each assignment. I love the unplugged activities and course handouts. The real test will be in front of my class. Looking forward for the coming school year.


#4

I will ask probing questions having students connect their experiences in video production and photography with compression.


#5

If there is time I’d really like to do an investigation for the Interesting Point in the wrap up.


#6

The lesson walk the students through the necessary information to understand what is happening in the back ground. I am impressed with the way the lessons lead them through to understand pictures, bits, pixels and how this all fits together. And finally, the discussion and lesson on compressing files and formats is extremely valuable in getting students to understand that bandwidth is finite and can be surpassed causing problems.


#7

I cannot open the File Formats Rapid Research Handout. I like the idea behind this but I think it is thin on material.


#8

I was able to view that File Formats handout here: https://docs.google.com/document/d/1NBWm2COywzZo7jET68Ars5j-0QAtIp3zw42tdKl304g/edit#

Although the first Code Studio link in the LP does seem to be bad. Should link here: https://studio.code.org/s/cspunit1/stage/16/puzzle/1

There’s just an intro with a link to the Activity Guide and the Widget there, and then a matching check for understanding. Not vital to understanding the lesson, but hopefully someone sees this and updates the LP doc. Not sure the best place to report such issues…


#9

I plan to use this lesson pretty much as is, making digital copies of the File Formats doc in Google Classroom and having students work on it and turn it in to me there. They will also complete the matching check for understanding in Code Studio at the end of class, and we will discuss the answers there if time allows or the following day.

Since students will be working on their research findings in pairs, only one student from each pair will turn in a document to me. For those using Google Classroom (this will be my first year using it), here are some reasonable-sounding tips for handling group work: http://www.alicekeeler.com/teachertech/2014/10/25/google-classroom-turning-in-group-work/

Will definitely hit on the Interesting Point about filename extensions when pairs share out and discuss their research findings.


#10

I think the students will enjoy the widget and using it.


#11

I think this chunk does a great job in building the knowledge about how information is stored. The lesson goes back to using single bits and then multiple bits to store color. I plan on using the lessons as prescribed.


#12

I really like how this chunk of lessons starts with text, which I think is a much easier concept for students to grasp, especially with the use of the Code Studio tool that gives immediate feedback. Starting with this will make it a lot easier for students to follow the progression into compressing pictures, which is something the students care more about (all their selfies!).


#13

I will use the lessons as provided, this is not something I know much about. This should clear up some confusion or misconceptions students commonly have though, about what the file extensions are all about.


#14

I think that I would like to showcase some real world examples of how compression is done. For example. take a standard audio CD and “rip” the files into an MP3 of OGG format. Most applications for this purpose allow you to set the sample rate or compression ratio. We can experiment either in small teams or with the classroom digital projector. Students can guess the percentage of file compression and check the results.

Similar work can be done with a PDF file creation, I would also suggest trying this task with image files. Programs that convert/save to JPEG (such as Paint.Net) have sliders to allow the user to select the level of compression. We can determine as a class or in small groups which level of compression is acceptable for a given scenario. Would it work on a phone screen but not be acceptable printed as an 8*10 photo?


#15

I responded to units before and I feel that students need to get some minimum information from each lesson to be able to connect with the next. Its just on me to figure what that is and who has got it and what do I need to re-teach to not have a “lossy” unit. Students might get this unit even if other concepts are not totally clear about every concept. I will use all provided examples. Also for this chunk to show pixels I will use photoshop and blow up a pic to show.


#16

I’m with Katherine, I will not be modifying these lessons until I know more about the content myself. Hoping the students can teach me a thing or two.


#17

As mentioned by others, I will pretty much run with the lessons as is. I like that they are all centered around text/data compression and thus give different perspectives to the students. It should also help them understand why certain images first appear fuzzy when they see them and then slowly become clear as some time passes.


#18

Is it possible to see an answer key for the rapid research activity? I’m not sure how in depth the students should know the material. Thanks.


#19

Hi Tiffani

Thanks for reaching out about this. We don’t currently have any formal rubric or exemplar for this activity yet. Its definitely a good idea of something we should add for the future. However, in the meantime, we will work on creating some guiding points to post here . We will get those to you as soon as possible.

-CSP Team


#20

hey, tiffani!

here’s a quick example of the kind of answer you might look for in the rapid research portion of this lesson: