Joan got A's on all her homework assignments, so if she had gotten an A on her term paper, she could pass the course even without doing the class presentation. ██████████████ ███ ███ ███ ███ ██ █ ██ ███ ████ ██████ ██ ██ ██ ███████ ████ ███ ████ ████ ██ ██ ███ █████ ████████████ ██ ████ ███ ███████
The author concludes that Joan will have to do the class presentation to pass the course. He supports this by saying that if she’d gotten an A on her term paper, she could pass the course without doing the presentation, but she didn’t get an A on her term paper.
This is the flaw of mistaking sufficiency for necessity. The author treats “A on term paper” as necessary for “pass without presentation.” But in his premises, “A on term paper” is merely sufficient. So not getting an A on the term paper tells us nothing about whether she can pass the course without doing the presentation.
Maybe there are other ways Joan can pass the course without doing the presentation. For example, maybe if she got a B on the term paper, she’ll still pass without doing the presentation.
The argument's reasoning is questionable ███████ ███ ████████
ignores the possibility ████ ████ ████ ██████ ████ ██ █ ██ ███ ████ █████ ██ ██ ███ █████ ████████████ ██ ████ ███ ██████
presupposes without justification ████ ██████ ███ ███████ ██ █ ██ ███ ████ █████ ████████ ███ ████ ███████ ███ ██████ ███████ █████ ███ █████ ████████████
overlooks the importance ██ █████ █████████████ ██ █ █████████ ███████ ██████ █████
ignores the possibility ████ ██ ████ ███ ██ ██ ███ █████ ████████████ ██ ████ ███ ███████ ████ ███ ███ ███ ███ ██ █ ██ ███ ████ █████
fails to take ████ ███████ ███ ███████████ ████ ████ ████████ ███ ███ ██ █████ ████ ██████ ███ ██ ███ ████ ███ ██████