Local people, with general information on the subject, can give valuable help in explaining points about particular exhibits which have to be repeated many times. These helpers should receive advance material and in addition should come to the train for coaching before it opens and be stationed at assigned positions. Staff members who are continually meeting people, work under considerable strain and may easily become tired or indifferent through over-work. So much depends on their enthusiasm and their readiness to offer help that this factor should be carefully checked up, and if any member of the staff shows signs of losing interest or failing to get a response he should be replaced or at least given a period of rest. By relieving staff members of irksome details and by providing in other ways for their comfort, as well as by arranging the schedule of hours so that they do not work beyond their strength in any one period, much can be done to avoid this loss of freshness and enthusiasm. FOOTNOTES: [8] The discussion in this section is handled in terms of trains for the sake of clearness and convenience, but generally the application is to single cars as well as to trains, and to automobiles or motor trucks or caravans of the same. The paragraphs not applicable to trucks are fairly obvious. However, it is urged that maximum results from a truck tour call for much the same carefully detailed preparation and management as a tour with a train. [9] This fact, further discussed on p. 105, deserves considerable emphasis. IX FOLLOW-UP WORK In a previous chapter it was pointed out that the purpose of a tour may be to give information, to create interest in a new movement that is being launched, to revive interest that has become dull, or to serve as an attention-arresting feature of an intensive campaign that aims to produce some immediate results. All of these aims point to the need of planning definite follow-up work. It will not do to let people forget what they have learned or lose interest in it through neglect. If the tour means simply that ideas or facts are dropped down into each community, like seeds scattered by the winds without provision for later cultivating, they have a smaller chance to take root and grow. Psychology has demonstrated that there is a “curve of forgetting.” Hollingworth described it as follows: When a given appeal is addressed to me, I straightway proceed to forget it. But I do not forget it at a uniform rate, so much being forgotten on each succeeding day until all is forgotten. Instead, I forget the material that has been seen or learned, according to a definite “curve of forgetting,” a curve which descends rapidly at first and then more slowly. The larger proportion of material is forgotten in the first day or so. After that a constantly decreasing amount is forgotten on each succeeding day.[10]