Not only a lack of right definitions: Arguments for a shift in information-processing paradigm.

link: http://arxiv.org/abs/1009.0077
Abstract

Machine Consciousness and Machine Intelligence are not simply new buzzwords
that occupy our imagination. Over the last decades, we witness an unprecedented
rise in attempts to create machines with human-like features and capabilities.
However, despite widespread sympathy and abundant funding, progress in these
enterprises is far from being satisfactory. The reasons for this are twofold:
First, the notions of cognition and intelligence (usually borrowed from human
behavior studies) are notoriously blurred and ill-defined, and second, the
basic concepts underpinning the whole discourse are by themselves either
undefined or defined very vaguely. That leads to improper and inadequate
research goals determination, which I will illustrate with some examples drawn
from recent documents issued by DARPA and the European Commission. On the other
hand, I would like to propose some remedies that, I hope, would improve the
current state-of-the-art disgrace.