Research has shown that time concepts are attained in a developmental manner but that learning is affected by guided training, experience, and maturation. Time concepts abound in textbooks. Indefinite time concepts are especially difficult for children to interpret. Efforts to simplify vocabulary may result in terms more vague and difficult to understand than if specific dates are used.

Time lines, combined with other instructional materials, improve children's understanding of time and chronology. Most literature promoting time lines suggests writing events already known, understood, or common to the experiences of children. Refer to listings in the bibliography for more detail on these points of view.