It is a problem, especially for beginning readers who struggle to comprehend as they're reading and don't have the 'bandwidth' to parse the incorrect sentence a

It is a problem, especially for beginning readers who struggle to comprehend as they're reading and don't have the 'bandwidth' to parse the incorrect sentence and find their place in the text on the fly. Stressful situations (tests, public reading in front of the class, etc) likely make this worse.