Grid in CSD not the same as CSF - bug or feature?

CS Discoveries Unit and Lesson Discussion
1

Hi, I discovered the grid in CSF and CSD are not the same. Is this a bug or feature?

In CSF, 0,0 is the lower left hand corner of the grid, in CSD 0,0 is the upper right hand corner of the grid. What gives?

I made a YouTube video to explain/demonstrate: https://youtu.be/d7gzxKvCqGo

2

Hi @michael.wesley,

I know it is confusing! I am going to piggy-back off of @mwood’s answer HERE. When you think about it from the television/screen point of view and the fact a program is read from top to bottom, it makes a little more sense. Python’s Pygame library also uses the same coordinates in that 0,0 is in upper left (see here and here).

Hope that helps a little,
Michelle

3

This Stack Exchange discussion goes into some depth about it too.

I think this is a great example of industry saying “we do it that way because it made sense to do it that way a long time ago and now it would break too many things to do it in a way that makes more sense for today, so we’re leaving it as is.”

–Michael K.

4

Hi Michelle,
The only confusion that I have is one product with two systems for scaffolded curriculum. I accept this is the way that it is. CODE.ORG is the best …

My question was not answered. The grid system is not consistent CSF vis-a-vis CSD - Bug or Feature?

Thank you,
MW

5

Ok…whys are important. I’m guessing not a bug but let me dig a little deeper into the pedagogical reasons for the CSF grid and get back to you.

Michelle

6

Hi Michael!

Thanks for the video & the feedback, especially your attention to the student experience of going from one frame of reference to another. Here are some answers to your concerns:

The short answer is: it’s intentional, based on feedback from teachers. Originally, both tools worked the same with the (0, 0) point in the upper-left hand corner. This is consistent with how computer graphics work beyond CSF or CSD - but, as you mentioned, this isn’t the same way students learn coordinates in math class. After some piloting and feedback with classroom teachers, we received overwhelming feedback from CSF teachers that it made more sense to change the orientation of the (0, 0) point in CSF so it matched students’ mathematical learning and to better support teachers who wanted to integrate CSF activities into math classes (since the origin points would be the same in both places). However, we didn’t make this change to CSD so it could remain consistent with other applications of computer graphics and scaffold to other tools (such as AppLab) which also orients the (0, 0) point in the upper-left corner.

Students first start drawing in Unit 3 Lesson 3 of CSD. Even though this video at the start of the lesson explains that the origin point starts in the upper-left corner, we’ll look into making this more clear in the lesson plan to better support teachers & students who are building from CSF to CSD.

Cheers,
Dan - CSD Curriculum Writer

4 Likes