ListLengthCannotBeZero

DRAFT

Not Observed

Correction

Here is what's right.

When we create a new list, it already starts out empty.

Moreover, we can remove all elements from a list with

or we can remove individual elements with

and thus empty a list completely.

We can check the length of an empty list with

and will receive 0 as a result.

Unlike in most programming languages, in Scratch we cannot programmatically create new lists. We can only create lists while “programming”. Thus, we believe that this misconception is highly unlikely in Scratch. Students will see an empty list (represented as a ”Stage Monitor”) whenever they create a list interactively.

Origin

Where could this misconception come from?

Students might mistakenly believe that an empty list is not really a list, similar to the mistaken believe that 0 is not really a number.