Scientific MethodsI. Hypothetical – Deductive Method

many hypothesis (ideas),

eliminate those without data to support them

II. Correlation Method

multi variable situations

Use statistics and computer models to compare data to situations

(predict the weather)

Steps in (a) Scientific Method (Hypothetical – deductive)

Used more like a flow chart than a list1. Observation

Curiosity, skepticism, senses/ observations, experiences

2. Question “Why? , How? , What if? “3. Research

background information , look for an answer, list all possible explanations, what you already know

4. Hypothesis“If – then – therefore” statement, cause and effect, educated guess, prediction, testable/ measurable, “explanation on trial”… claims and statements

Scientific method continued

5. Design an Experiment Independent variable – “manipulated variable”

I/ the scientist manipulate or investigate, only 1, the “IF”.., what is being tested/varied/modified/changed by the researcher, x axisDependent variable – “responding variable” depends on what I did (independent)… plant is TALLER because of the fertilizer, “Then”, what is measured/changes, y axisControls – everything you keep the same so that there is only one independent variable., comparison/ base line, ‘control group’

Scientific method continued6. Collect data (during and after experiment)

numbers and units – quantitative data (quantity or amount), descriptions = qualitative data (quality of something)7. Analyze data

Put into tables, charts, graphs, look for TRENDS and correlations between Ind.V and Dep. V., relationships. Show work, calculations and formulas

Either verify or falsify your claim with these steps– retest, restart, restate, re-evaluate

8. ConclusionDoes your data show support for your prediction…. Accept Hypothesis or

declare Null Hypothesis. Explain what happened, what your results were and where you could improve/change (error analysis is statistical work done to show the precision of your measurements)

Do not say “Prove” – you didn’t prove 100% forever, you supported or eliminated, until there is new evidence

9. Repeat/ report/ publishLab report or publication – grant money, peer review, share results, more

testing, etc.

Assignment – this may be done individually or in collaboration with a lab group 1. on a sheet of plain paper (or your

iPad) create a flow chart version of the steps usually covered in a scientific experiment.

2. Read page 29 - 31 and list the steps taken by Rita Colwell to verify or correlate that water temperature is an indicator of cholera risk.

3. Choose an article from the red folders provided and list the steps taken during a classic experiment (Redi, Lister, Pasteur, Jenner, etc)

What was the hypothesis or claim?

Set up/ control group, procedure

Independent variable,

dependent variable,

data or results,

Conclusion/ eliminate or support