Vocabulary and Basics
This is a tentative explanation or model for observations that leads to testable predictions.
What is a hypothesis?
The variable you change on purpose in an experiment.
What is the independent variable?
According to our class, avoid writing hypotheses in this common school format.
What is 'if…then' format?
Good or bad? 'Non-urban streams are better than urban streams.'
Bad, too vague; 'better' is undefined and not testable.
The statement of 'no difference' or 'no relationship' is called this.
What is the null hypothesis (H₀)?
Two properties of a good hypothesis.
What is testable and falsifiable?
The observed impact (effect) affected by the change.
What is the dependent variable?
Rewrite as a proper hypothesis (no if-then): 'If tuna swim faster, then they need more oxygen.'
As tuna swimming speed increases, oxygen demand increases.
Improve this: 'Non-urban streams are better than urban streams.'
Non-urban streams have higher mayfly abundance than urban streams.
The statement proposing a specific difference or relationship is called this.
What is the alternative hypothesis (Hₐ)?
Type of reasoning that makes generalizations from specific observations.
What is inductive reasoning?
Factors kept the same across treatments.
What are controls?
A hypothesis must clearly state what is changed
(independent variable) and what is affected (dependent variable) are measurable and/or observable , this quality is called ______.
What is testable?
Good or bad? 'When compared at the same size and temperature, tunas have a higher maximum sustained speed than mackerels.'
Good, clear, specific, testable
Give H₀ for: 'Shallow ponds have larger juvenile fish than deep ponds.'
H₀: There is no difference in juvenile fish size between shallow and deep ponds.
A set of related hypotheses that has withstood repeated tests is called this.
What is a theory?
Name the independent variable in the following question: 'Does water temperature affect juvenile fish growth rate?'
What is water temperature?
A hypothesis must use data collected to determine if the hypothesis is supported or false, this quality is.
What is falsifiable?
Good or Bad? Higher study time increases student grade.
Good
Give Hₐ for: 'Water temperature affects juvenile fish growth rate.'
Hₐ: Higher water temperatures increase juvenile fish growth rate.
The ongoing, self-correcting nature of science is due to this repeated process.
What is the scientific method?
Fill in the pattern of a testable question with I.V and D.V : 'How does ______ affect ______?'
How does __I.V__ affect __D.V__?
Write a hypothesis:
Independent variable: rainfall
Dependent variable: plant growth
Greater rainfall leads to increased plant growth.
Spot the issue: 'Plants prefer music.'
Too vague; needs measurable IV and DV
True/False: We can prove a hypothesis true.
False. We can find support but not prove truth definitively.