The proposed levels theory presented in this book concerns some developmental changes in the capacity to selectively encode information and provide rational solutions to problems. These changes are measured by the behavior exhibited in simple discrimination-learning problems that allow both for information to be encoded either selectively or nonselectively and for solutions to be produced by associative learning or by hypothesis-testing.
The simplicity of these problems permits comparisons between infrahuman and human performance and also between a wide range of ages among humans. Human...

The proposed levels theory presented in this book concerns some developmental changes in the capacity to selectively encode information and provide rational solutions to problems. These changes are measured by the behavior exhibited in simple discrimination-learning problems that allow both for information to be encoded either selectively or nonselectively and for solutions to be produced by associative learning or by hypothesis-testing.
The simplicity of these problems permits comparisons between infrahuman and human performance and also between a wide range of ages among humans. Human...