Transcript Document

Scientific Method Revisited
With other odds and ends: constants,
control groups, significant and nonsignificant, and data recording
Scientific Method Revisited
Writing a Hypotheses
• Three ways:
1. As a question: Does temperature affect
fermentation?
2. As a conditional statement: Temperature may
affect fermentation
3. Very formally as an “if. . .then” statement: If
fermentation rate is related to temperature,
then increasing temperature will increase gas
production.
Another Example of a Formal
Hypothesis
• If skin cancer is related to ultraviolet light,
then people with high exposure to UV light
will have a higher frequency of skin cancer.
• Our independent variable is exposure to UV
light.
• Our dependent variable is frequency of skin
cancer.
Why Is a Hypothesis Important
• It guides research and helps to direct a
scientist’s thoughts.
• For a research project to be successful, it
needs be driven by a hypothesis, no matter
how tentative.
• Hypotheses can change as data is taken and
analyzed.
Constants and Control Groups
• A constant is a variable that doesn’t change
during an experiment.
• Control Group – A ”group” in a scientific
experiment where the factor being tested is
not applied so that it may serve as a standard
for comparison against another group where
the factor is applied.
Quantitative Data
• Quantitative data is numerical data measured
or identified on a numerical scale.
• Numerical data can be analyzed using
statistical methods, and results can be
displayed using tables, charts, histograms and
graphs.
• Examples: number of individuals in a herd,
spots on a Dalmatian, the number of acorns in
a given area, etc.
Qualitative Data
• Data which describes or characterizes but does
not measure, numerically, the attributes,
characteristics, or properties of a thing or
phenomenon.
• Examples: smells (rotting eggs), colors (the coat
of a lion), body language (hair standing on end of
a dog or your mother with her hands on her hips
staring at you) – it is highly perceptive and often
contains a narrative (case studies and
ethnography).