Do "overview" sections increase learning outcome? Suppose a math textbook contains an overview chapter for each part of the textbook. The intent of those overview chapters is to motivate and introduce the new mathematical concepts which will be discussed in the respective part of the textbook. For example, why do we need the mathematical concept? How did the concept evolve in history? What will be the content of the next chapters?

In this context, will the overview sections facilitate learning? How important are overview chapters in textbooks for the success of learning?

Note: I reasked this question on matheducators.stackexchange.com.
There is something called "advance organizer", that traces back to Ausubel (1960). It is some kind of overview, in which a short summary is given and (more important), in which the following  topic is connected to prior knowledge (= Associations are being activated). In that sense it activates schemes, in order to assimiliate the new knoweldge to the old one or to accomodate/correct the prior knowledge. So, to be useful, advance organizers should have certain features:


Connections between the following topic and prior knowlege
Catch the attention of the student
Be concret, insted of abstract


F.e. Before teaching equations the teacher could give the analogy of a scale. 

From a scientific perspective it is known, that advance organizers can have supportive effects on learning and retention (see f.e. Luiten, Ames &amp; Ackerson, 1980)

Luiten, J., Ames, W., &amp; Ackerson, G. (1980). A meta-analysis of the effects of advance organizers on learning and retention. American Educational Research Journal, 17(2), 211-218.