In a study to determine procedural effects of volume conservation tasks performed by adolescent females, the results revealed that the LaVatelli water displacement test was significantly more difficult than the Elkind test or Piaget's test. (Author/RL)

Reports that spatial ability was unrelated to formal reasoning task performance. Notes that sex differences occurred with balance tasks and pendulum tasks, suggesting male superiority at manifesting proportionality and isolating variables. (Author/RL)

This study had two purposes: (1) to determine when children distinguish ambiguous from precise messages and when they can resolve ambiguity through additional questioning, and (2) to identify whether implicit messages were more difficult to identify than explicit ones. All children found ambiguous messages significantly more difficult to…