Not sure where you got that definition of science from, it is not very good.
A quick search of Wiki gives a much better one...
"Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe"
or from elsewhere on the web...
"The intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment."
They simply say, that the Popper's Scientific Criterion is the Scientific Method to Extract Knowledge.
So, basically, they say, that Science is process of extraction while using Scientific methods. But, this definition can be greatly shorten: "Science is knowledge extraction." Then after the definition in a fair textbook the description would follow: "Science is composed of main sections, such as: Methodology, Metrology, and Disciplines (Physics, Mathematics, Chemistry, Art, History, Philosophy, Psychology, Theology)."
P.S. Some mistakes of peer-review system, and Alternative to Popper Criterion are in the attached file. Would somebody help to publish the article?