Loop or Function?


#1

On the Unit 3 quiz there are a series of questions about loops or functions. One of the questions asks whether you would use a loop or a function in order draw a circle of any size at any point on the screen. The answer is a function, but my student has pointed out that a loop could also do that (and in fact they do that when creating their digital underwater scene). What is the difference here? Is it that they aren’t necessarily drawing multiple circles?


#2

“would use a loop or a function in order draw a circle of any size at any point on the screen”
This question was for a single circle of any size and drawn at any point. The only way you could use a loop to do multiple circles of varying sizes and the random function for the centers.
So the correct answer is function in order draw a circle of any size at any point on the screen"


#3

Thank you! I realized once I was asking this question that it didn’t mention how many circles and that was probably the key to the question.


#4

I was similarly frustrated with this question. I understand why the expected answer is function, but from my perspective the question has two correct answers. I would use a function at the top level to abstract the details, and then inside the function I would create the circle by running a loop with a series of move and turn commands - unless I already had a function to draw a circle, in which case i don’t really need to do either.


#5

Hi All!

I would say this is a question of what the BEST answer is for a question. You could use a loop, but then you would need to change the values multiple times in the loop based on the size and location of the circle. For this reason, you would want to use a function.

I think the students’ objection is fair, but I always tell students that on many multiple choice tests there maybe a few suitable answers but one BEST answer.

I’d be interested to hear how others deal with this!
KT


#6

All really good and thought provoking test questions are subject to interpretation at some level. If a student of mine has a reasonable argument and can justify their position objectively, I will normally award credit. Then I will make adjustments to the wording for the next test administration.


#7

I like this a lot. Especially since I’m teaching this as an AP course, it’s important practice for students to understand that sometimes other answers can be justified, but that the BEST answer must be the one they pick.