Fans of the book "Understanding Comics" by Scott McCloud will be pretty pleased by this subsection, since it is about induction. Induction is the process which takes place in the viewers' (or readers') minds, when they put all the little pieces of information presented to them together. But there is more than that. Since time plays a major role in films, it is also important, when and in which order the information is given. It is comparable to weaving a delicate pattern, with the difference that you use information instead of coloured threads.
Here is a simple example for a general understanding. At first it is not clear where the scene takes place. This piece of information is presented bit by bit to the viewers and catches their interest this way. From the very beginning you involuntarily wonder for a short moment if Sara is behind the window or if it is a mere reflection. Then you wonder, also involuntarily, where this window actually is. The final solution takes some time, so the viewers are involved much better as in the ordinary case, where the scene would have started with the long shot (total view) right away.
I think you get the idea now. The intention is to achieve "active viewing", to make the viewers stick it out. You might suspect that this primarily lies in the responsibility of the screenplay. Some of you surely remember the infamous preaching at school to have to "read between the lines". But this also holds for the direction. The impact is even a more direct one, since it is a consequence of the immediate perception.
The example above deals with a location, which is revealed gradually. This is also possible with other information. Generally it can be said that the following kinds of informations can be treated that way:
The method in all cases is the same, though. At first only the first bit of information is revealed, but it has to be consistent with the overall view. The viewers are now interested in what comes next. From now on there are two possibilities, depending on the intention of this scene. you can reveal more tidbits and leave it to the viewers to fill the gaps between them. This is the general case and it is used to fill the whole scene with more spirit. Or you want to surprise the viewers by first leaving them in the dark for a while and then presenting the solution. The example with Sara and César two pages before exactly matches this case. However, there is no clear dividing line between the two of them.
This picture represents the second point above. At first we ask ask ourselves: What did Sara see? Why does she look pleased and runs outside? Only afterwards we, too, can see the postman. Note, that Sara and the postman are never visible both at the same time. The overall view appears only before our mind's eye.
Finally you can even hint at forthcoming events or actions. I have noticed that especially in this case, a tight atmosphere can be created. Perhaps this is the reason why many scenes in "A Little Princess Sara" are filled with an extraordinary intensity. The effect is attained by creating a sense of expectancy which gets fulfilled afterwards. It can be of an anxious nature, the fear of future events, but also pleasant anticipation. I will give the example now.
The day is drawing to a close and Becky was shown in the scene just before. Our attention is now drawn to Sara, but not without reason. She is waiting for Becky to talk to her. We do not know it for sure but we sense that it must be so, exactly because of the previous scene.
Suddenly, the sound of footsteps are heard from the outside. Sara's reaction shows us that she, too, has heard them. And even more than that, that she was expecting them. It is for sure now. It must be Becky, who is announced by the steps.
Meanwhile Sara concentrates her thoughts fully upon the sound of the steps. Her head rises, the hands which hold the now insignificant piece of paper, which was formerly a letter, sink back to the desk. She will act really soon now!
Shortly afterwards we see, that it is indeed Becky, who walks past outside.
So it is just a matter of time until the door opens and Sara steps out to invite Becky to join her in her room. A little bit later, Becky is being told by Sara, what we already know: that Sara has been waiting for her.
If you reflect upon all three examples it is immediately clear that information can be imparted by different means. Simply by the camera, by reactions of the characters or by acoustic signals as in the scene above. But now this last point arouses a suspicion that we have perhaps forgotten something crucial.