Mill's Method of Agreement
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
If the cases where the effect occurs share exactly one factor, that factor is the candidate cause.
Show
Five sick diners, five different meals, one shared dish.
Watch for
"Exactly one shared factor" is an idealization — real cases share dozens. Agreement narrows the field; it doesn't close it.