experimental biology Flashcards
What are the stages of the scientific method?
(when new observations are made)
- observation
- hypothesis
- experiment (where the hypothesis is tested)
- conclusion (the hypothesis is supported or rejected)
- scientific theory
When is the scientific question formed?
It is formed after you observe something curious.
What are the aspects of the scientific question?
- must combine what is already known
- must be answerable
- must be testable
What are the three ways of verifying the hypothesis?
- observation
- research
- experiment
What is the hypothesis?
A hypothesis is a statement that provides a possible answer to a question or an explanation for an observation that can be tested. ?proposed explanation for a phenomenon
What are the features of a hypothesis? (4)
- must be logical
- must account for all relevant information available
- must be testable
- must allow one to predict future events
How many groups must the experiment have?
2 groups (control group and experimental group)
What is the purpose of the control group?
The control group makes sure that THE factor is responsible for certain results.
What are the variables in an experiment? (3)
- independent (what I change)
- dependent (what I observe)
- controlled (what I keep the same)
What is a theory?
A theory is an explanation acquired through the scientific method.
What is a scientific law?
Law is a statement based on repeated experimental observation.
What are the names of the three main statistical tests?
1) student-T-test
2) ANOVA test
3) Chi-Square (x2)
How does the student-T-test work?
It compares the mean and standard deviation (a measure of how spread out a data set is).
When do we experience a null hypothesis?
When there is no significant difference between the two experimental groups (any differences may be due to chance or sampling error)
When do we experience an alternative hypothesis?
When there is a significant difference between the two experimental groups (the difference is not likely due to chance or sampling error)
When can we say that data is statistically significant?
If the error bars do not overlap.
What does ANOVA stand for?
ANOVA is an acronym for Analysis of Variance
How do we use the ANOVA test?
ANOVA can be done in place of multiple T-tests when comparing the means of more than two groups at a time.
What is the other name for the Chi-Square test?
Goodness of fit.
What does the Chi-Square test compare?
It compares observed data with the data we would expect to obtain.
What is a trend?
It’s a thing that appears to be found generally rather than just in specific cases.
What are the exceptions to a general trend called?
Those are called discrepancies.
