Participants rated Intuition, Suddenness, Pleasure, and Certainty accompanying their solutions to items of a popular fluid intelligence test -- Raven's Advanced Progressive Matrices (RAPM) -- that varied from easy (around 80% correct) to difficult (around 20% correct). The same ratings were collected from four insight problems interleaved with…

In confirmatory factor analysis quite similar models of measurement serve the detection of the difficulty factor and the factor due to the item-position effect. The item-position effect refers to the increasing dependency among the responses to successively presented items of a test whereas the difficulty factor is ascribed to the wide range of…

Spatial ability, particularly the cognitive capacity for mental rotations, is a critical component of human cognition. Proficiency with mental rotation tasks is linked with educational performance in various Science, Technology, Engineering, and Mathematics (STEM) disciplines, and with more general tasks such as real world wayfinding. Spatial…

The authors examined whether individual differences in fluid intelligence (gF) modulate the testing effect. Participants studied Swahili--English word pairs and repeatedly studied half the pairs or attempted retrieval, with feedback, for the remaining half. Word pairs were easy or difficult to learn. Overall, participants showed a benefit of…