Online learning or e-learning is becoming an emergent learning method that several institutions have deployed at their organizations. Initial achievements of online learning environment have partially proved its outstanding features. However, a comprehensive evaluation of the existing online learning systems is necessary, especially effective evaluation of online learning environment comparing with traditional learning environment. In this book, a framework to measure comparative effectiveness between two these learning environments was developed based on Kirkpatrick's four-levels evaluation model and then a case study was applied to test two first levels of the framework. These four evaluation levels include participants' reaction, learning achievements, behaviour of students, and results. The results of data analysis based on hypothesis testing indicated that between two first levels that were tested there is a significant difference in students' learning achievements in favor of online learning method.