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Introduction
Foundations of Biological Research
BIO594
• Observation and description of a
The Scientific
phenomenon
or group ofMethod
phenomena
Formulation of an hypothesis to explain the
phenomena
A causal mechanism or a mathematical
relation
Use of the hypothesis to predict other
phenomena, or to predict quantitatively the
results of new observations
Performance of experimental tests of the
predictions by several independent
experimenters and properly performed
experiments
Science
does not prove anything; it can only disprove
Hypothesis testing
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Hypotheses,
Theories of
and
• Hypothesis
- an Models,
offered explanation
a
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phenomenon based
upon observational
Laws
assumptions (“educated guess”)
Model - an experimental system in which part
of a hypothesis is true; useful for hypothesis
testing (i.e., produce facts)
Theory - generalizes statement(s) that
provide explanatory and predictive powers
for phenomena
All scientific theories require facts
Law - Parts of theories that have a
mathematical basis
Laws do not provide explanations, only
mathematical descriptions of phenomena
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Hypothesis
• In hypothesisNull
testing,
two mutually exclusive
statements must be addressed
Drug A will improve the patient’s condition
Drug A will not improve the patient’s
condition
Evaluation of hypothesis testing often relies
upon statistical analysis
If you have more than two hypotheses for a
phenomenon, then you must experimentally
address each of them
When you’ve disproved all but one
hypothesis, you must accept it, no matter
how strange it might appear
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Electronic Databases
• UNC Library (databases, interlibrary loan,
etc.)
http://library.unco.edu/ Articles A to Z
http://scholar.google.com/ Google Scholar
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Electronic Databases
• PubMed
• http://www.ncbi.nlm.nih.gov/entrez/query.fc
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gi?db=PubMed
Largest biomedical database
Maintained by the National Library of
Medicine
Easily integrated with personal computer
database software
Electronic Databases
• PubMed (cont.)
• Boolean Operators (MUST BE
CAPITALIZED)
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AND : includes search terms; "t cells" AND interleukin-23
OR : either search term; “t cells” OR interleukin-23
NOT : excludes a search term: “t cells” NOT interleukin-23
• Complex search; "t cells" AND hantavirus
NOT hantaan
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Electronic
Databases
PubMed (cont)
• Search Qualifiers
• au = author: schountz [au]
“schountz t” [au]
dp = date of publication: 2002 [dp]
la = language: english [la]
ti = words in title: hantavirus [ti]
tiab = words in title or abstract:
hantavirus [tiab]
Use of Parentheses for Complex Searches
(virus NOT bacterium) AND diabetes
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OR
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Electronic Databases
• Reference Manager Software
• EndNote
• Reference Manager
• These applications allow you to import
references from the online databases and will
format documents for publication or grant
submission.