Scientific Method Revisited With other odds and ends: constants, control groups, significant and non- significant, 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).