What is scientific method?
- Process of inquiry & experimentation to explore observations & ans questions
- Used to seek cause & effect relationship in nature
What are 6 basic steps in scientific method?
- Ask a question based on observation
- Background research
- Construct a hypothesis
- Test hypothesis w/experiments
- Analyze data & draw conclusion
- Communicate results
When doing background research what should we be doing?
- Learn about topic
- Read about previous related studies
What is a hypothesis?
- Testable educated guess about how things work
- If _________, then __________ will happen
When designing experiments to test hypothesis we have to do what 2 things?
- Decide what we are testing
- How we are going to test it
What is a variable?
Any factor, trait or condition that can exist in differing amts or types
What are the 3 types of variables?
- Constant (control)
Describe the independent variable.
- This is the 1 that is going to be changed by the scientist
- Gd experiments only have 1
Describe the dependent variable.
- This 1 is going to be unmanipulated JUST OBSERVED
- There can be more than one
- Changes in it are dependent upon the independent variable
Explain the controlled or constant variable.
- MUST remain constant throughout experiment
- ie # of cells, Data collection points, Environmental conds
What are ctrl groups?
- Groups used for comparison to your experimental group
- This grp gets no tx
- 2 types - pos & neg
Describe the pos ctrl grp.
- Has a known effect on the dependent variable
- Not always used
Describe the neg ctrl grp.
- Complete absence of independent variable
- For determination of significant changes in dependent variables
- ALWAYS IN DESIGN
What is the triplicate rule in scientific method?
At least 3 experimental trials ensure reproducibility of results
What are the 2 types data useful to scientific experimentation?
- Quantitative (quantity)
- Qualitative (quality)
Describe quantitative data.
- Numerical measurement gained w/instruments
- Can be measured, counted, have a numerical value
Describe qualitative data.
- Subjective to interpretation
- ie shape
- Photos & charts are good
How do we report quantitative data?
Statistical analysis to make sense of all the numbers
What is the confidence interval?
- A narrow segment where most of your data should fall.
- Expressed in a P-value
Explain the P-value.
This is the probability that you will fall within a 95% CI
If our data supports our hypothesis we should . . . .
- Report results
- Conduct more tests to refine
If our data does not support our hypothesis we should . . .
- Report our results
- Use it to form new hypothesis
- Begin testing new hypothesis