The trade-off between internal and external information storage

External information storage is an alternative to memorizing which contributes considerably to the efficiency of human knowledge preservation. Three experiments on the trade-off between internal and external storage are described. In all three experiments, subjects had to prepare a report based on text materials which were successively displayed on a screen. The subjects could produce printouts of texts, instead of or in addition to memorizing them. Text relevance and text complexity had an impact on inspection time and printout rate; the complexity effect was particularly pronounced with hierarchically ordered texts. Increasing operational costs for starting the printer depressed the printout rate, and led to a shift toward memorizing. The dissociation of the agent of encoding and the agent of retrieval was studied by asking subjects to prepare a report to be written by a partner. Under this condition, the printout rate was inflated, especially for texts of intermediate complexity. The hypothesis is put forward that retrieval from an external store and the merging of internally and externally stored materials require an internal representation of external storage.