From Oxford Dictionaries [http://oxforddictionaries.com/definition/english/science], accessed 12/06/13
Definition of science
the intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment: the world of science and technology
a particular area of science:veterinary science [count noun]:the agricultural sciences
a systematically organized body of knowledge on a particular subject:the science of criminology
knowledge of any kind: his rare science and his practical skill
From Dictionary of Philosophy [Peguin Reference], 2000
science, n. Even in writings as recent as those of Locke and Hume there are many passages where the words ‘science’, ‘scientific’ etc., derived from scientia (the Latin equivalent of the Greek episteme), are reserved for knowledge that is neccessarily the case. Such knowledge is demonstrated by rational intuition or by demonstration. This usage goes back to Plato and Aristotle.
From The Logic of Scientific Discovery, Popper 2007
…I do not demand that every scientific theory must have in fact been tested before it is accepted. I only demand that every such statement must be capable of being tested….
From Philospohy of Science, Okasha 2002
…his [Popper’s] assumption that science has an ‘essential nature’ is questionable. After all, science is a heterogeneous activity, encompassing a wide range of different disciplines and theories…a simple criteria for demarcating science from pseudo-science is unlikely to be found.
Wikipedia: Branches of Science
The main branches of science (also referred to as “sciences”, “scientific fields”, or “scientific disciplines”) are commonly divided into two major groups: social sciences, which study human behavior and societies, and natural sciences [physical and life], which study natural phenomena (including fundamental forces and biological life). These groupings are empirical sciences, which means the knowledge must be based on observable phenomena and be capable of being tested for its validity by other researchers working under the same conditions.
In addition to empirical sciences, there are the formal sciences, such as mathematics and logic, which use an a priori, as opposed to factual methodology to study formal systems. These three categories make up the fundamental sciences, on top of which are interdisciplinary and applied science, such as engineering and medicine. Specialized scientific fields that exist in all categories can include parts of other scientific disciplines but often possess their own terminology and expertise.
From Computing: The Fourth Great Domain of Science, Denning and Rosenbloom, 52.9
It has a distinctive focus – computation and information processes. Its constituent fields – computer science, informatics, information technology, computing engineering, software engineering,and information systems – and its structures and processes are in constant interaction. Its influence is pervasive, reaching deep into people’s lives and work.
From Computing Science: The Discipline, Denning 1999
The body of knowledge of computing is frequently described as the systematic study of algorithmic processes that describe and transform information: their theory, analysis, design, efficiency, implementation, and application. The fundamental question underlying all of computing is , What can be (efficiently) automated?
From Dictionary of Computing [Peguin Reference], 2003
An academic discipline that studies, among other topics, the mathematics of computation, the properties of algorithms and the design of programming languages.
Any process that works on data to transform input into output. [see universal Turing machine]
A well defined set of instructions for solving a problem.