On the other hand, other studies have shown that if a short summary of the link's content is provided when the mouse pointer hovers over it, then comprehension of the text is improved. "Navigation hints" about which links are most relevant improved comprehension. Finally, the background knowledge of the reader can partially determine the effect hyperlinks have on comprehension. In a study of reading comprehension with subjects who were familiar or unfamiliar with art history, texts which were hyperlinked to one another hierarchically were easier for novices to understand than texts which were hyperlinked semantically. In contrast, those already familiar with the topic understood the content equally well with both types of organization.