As a seasoned researcher, Professor Hattie has made significant contributions in the field of education for many years. Some of his major interests have been models of measurement and evaluation and performance indicators. His two popular books Visible Learning and Visible Learning for teachers brought him to the limelight after 15 years of research that involved synthesis and meta-analysis of over 50,000 studies that focused on student achievement and factors that influence their performance. He has worked so hard to establish what exactly works to help learners achieve their full potential through what is commonly known as the “John Hattie Theory.“

In his research, he concludes that what really makes the difference is “knowing the impact.” In his work, he argues that specialized teachers are not only wedded on selected ideas but rather focus on the evaluating their influence on learners in order to re-structure their teaching approaches. According to him, visible learning involves teachers evaluating their impact by assessing the successes of their students while students should figure out teachers as key components in their learning processes. According to his analysis, learning is visible only if it is challenging as well as explicit.

The underlying message behind the theory is that educators and leaders in the sector need to be alive to the fact that the impact they have on students is enormous and that they need to rely on this realization to craft decisions that would go a long way in changing their approach to teaching. He asserts that while teaching, the following must be the guiding mind frames for effective teachers clear:

1.Evaluators of the impact they have on teaching
2.Teachers are change agents who should own their actions as they try to influence learners

1. Teachers should talk about how their students learn as opposed to how teachers teach
2. visualize student assessment as being feedback of their impact on students.
3. teachers should promote dialogue when interacting with students.
4. Teachers should enjoy the challenge and engage their students in taking part in their challenge.
5. Teachers should develop a positive relationship with their learners to enhance effective learning.
6. Teachers should foster a common language of learning in which all students understand the underlying concepts and issues.
   9.Teachers should teach their pupils the value of a number of attributes, including concentration, patience and deliberate practice.

John Hattie Theory concludes in his theory that the most powerful single influences that promote achievement is positive feedback. For feedback to be as effective as it should, it should be clear, purposeful, meaningful, compatible with learners’ priority level, and should be directed at the right level to allow learners engage and utilize the underlying strategies.