  The Internet of Things (IoT) applications have grown in exorbitant numbers,
generating a large amount of data required for intelligent data processing.
However, the varying IoT infrastructures (i.e., cloud, edge, fog) and the
limitations of the IoT application layer protocols in transmitting/receiving
messages become the barriers in creating intelligent IoT applications. These
barriers prevent current intelligent IoT applications to adaptively learn from
other IoT applications. In this paper, we critically review how IoT-generated
data are processed for machine learning analysis and highlight the current
challenges in furthering intelligent solutions in the IoT environment.
Furthermore, we propose a framework to enable IoT applications to adaptively
learn from other IoT applications and present a case study in how the framework
can be applied to the real studies in the literature. Finally, we discuss the
key factors that have an impact on future intelligent applications for the IoT.
