Post on 27-Dec-2015
SCI 105.020Scientific Inquiry
The Big Picture:Science, Technology, Engineering, etc
Topics
What is Science? Basic & Applied Research Science, Engineering, Technology: a car metaphor
Is Computer Science Science?
Body Of Knowledge
Does any body of knowledge qualified for science? Science is knowledge about the real (physical) world There is no other options than obeying the natural laws
Scientific statements/theories are testableThe tests are repeatableThe theories are consistent among each otherThe knowledge body is growing forever: there
is no end product
Organization Of Knowledge
Intra-disciplinary growth Physics
Astrophysics, quantum physics, nuclear physics Theoretical, experimental, computational physics
Interdisciplinary growth Physical chemistry & chemical physics Material sciences Environmental sciences
Scientific Processes
The Micro-process: The six-step program
The Macro-process The Scientific Knowledge Acquisition Web (SKAW)
(see attached illustration)
Methodology/Philosophy of Science
Positivism: hypothesis-experiment-evaluation Propose a possible explanation of how something works
and then test it
Falsification: theory-falsification-modification Seeing a million swans that are white cannot prove that
“all swans are white”, but finding one that is black disproves the theory
Relativism: emphasizing the social factors in the conduct of science(to be continued)
Methodology/Philosophy (continued)
Relativism Science is assumed to be objective: prejudices of the
scientist do not affect the results presented Scientists are human
“The scientist does not record everything he observes but only those things which the theories he accepts indicates significant”
Science is theory-laden: theories strongly influence how science is done
Relativists suggest that science is a problem-oriented endeavor that can effectively solve problems even if it does not explain objective reality
Basic & Applied Research
Basic research (or pure science) is driven by the curiosity of the scientist A wonder about a particular phenomenon: e.g., the
evolution of the universe
Applied research is done to solve a specific problem Usually leads to new or improved technology, which is
the practical application of scientific knowledge
Basic & Applied Research: An Illustration
Nuclear Physics:
Fundamental nature of matter
Nuclear weapons
Medical devices
Reactors
Resulting technologies
Nuclear weapons
Nuclearmedicine
Nuclear energy
Applied research
Basic research
An Automobile Metaphor
Basic & Applied Research: The Interactions
Applied research relies on basic research to provide the underlying ideas
Basic research affects the society through the results of related applied research
Basic research can be empowered by new technologies made available by applied research Biology is traditionally experimental Computational biology/bioinformatics is very popular now
with the state-of-the-art computing technologies
Is Computer Science Science?
Definitions of Computer Science The study of computers and the major phenomena that
surround them Computer science is the body of knowledge concerned with
computers and computation. It has theoretical, experimental, and design components and include
(1)theories for understanding computing devices, programs, and systems;
(2)experimentation for the development and testing of concepts; (3)design methodology, algorithms, and tools for practical
realization; and (4)methods for analysis for verifying that these realizations meet
requirements
A Modified Definition
The discipline of computing id the systematical study of algorithmic processes that describe and transform information: their theories, analysis, design, efficiency, implementation, and application.
The fundamental question underlying all computing is “What can be (efficiently) automated?”
What Computer Scientists Do?
Sub-areas in Computer Science Algorithms and data structures Programming languages Architecture Numerical & symbolic computation Operating systems Software methodology & engineering Databases & information retrieval Artificial intelligent & robotics Human-computer interaction
Paradigms For The Discipline
Theory(rooted in mathematics) Characterize objects of
study (definition) Hypothesize possible
relationships among them (theorem)
Determine whether the relationships are true (proof)
Interpret results
Abstraction (or modeling)(rooted in experimental scientific method) Form a hypothesis Construct a model and make
a prediction Design an experiment and
collect data Analyze results
Design (rooted in engineering) State requirements State specification Design and implement the
system Test the system
The Role Of Programming
Computer Science Programming However, programming is part of the standard practices
of the discipline Programming languages are useful tools for gaining
access to the distinctions of the discipline Programs are instructions to the computing devices
written in programming languages Data structures: the way to hold information in a program,
e.g., a list of orders to an online bookstore Algorithm: clearly specified way to process the information,
e.g., process the order sequentially
Computer Algorithms
Computer algorithms often involve obtaining input, performing a calculation, and producing output.
An algorithm for converting from Fahrenheit to Celsius:1. Display a message asking the user to enter a Fahrenheit temperature.2. Obtain the input entered by the user.3. Convert the user’s input into numerical form.4. Calculate the equivalent Celsius temperature, using the formula
C = (F – 32) (5 / 9)
5. Convert the Celsius temperature into character form and display the result.
What Do Computers Do?
A computer system is an integrated collection of hardware and software components
Hardware refers to the electronics inside a computer
Software consists of (O/S and application) programs that tell the hardware what to do
Object-Oriented Programming
A software system (or a collection of programs that support a certain application) can be seen as an imaginary software machine It is constructed from parts: software objects Each object encapsulates scripts and information (think
of algorithm and data structure): its responsibilities Information: an object needs to know Scripts: operations that an object needs to do
Example: a bicycle object may be responsible for Information: which gear it is in Operations: start, change to a certain gear as specified,
stop
Responsibilities & Collaborations
To fulfill one of its responsibilities, an object may need to ask other objects for help: collaborations
Objects collaborate with one and other by means of message passing
There are three elements in a message Recipient Operation Additional information