Randomization should be employed whenever possible but the use of carefully controlled nonrandomized data to estimate causal effects is a reasonable and necessary procedure in many cases. (Author/BJG)

The present study attempted to replicate the finding (Frase, 1973) that different organizations of a passage produce different levels of recall and also to determine if relevant learning might be less subject to these organizational effects than incidential learning. (Author)

Humphreys' comments on double-median splits (TM 504 009) are essentially correct, but are not relevant to the original Kirby and Das article (EJ 182 444). His comments do not weaken our findings. (Author/RD)

The present experiment was performed in order to investigate learning efficiency within four different ethnic groups: black, white, Chinese-American, and Spanish-American. In all groups, sampling was confined to children from low-socioeconomic-status communities. (Author)