Scientific Method to Interpret a Scientific Investigation

What is a hypothesis? How is this created (2)

Informed guess about a relationship; from observation and data

What is a scientific hypothesis? (include what it’s based on)

Prediction based on prior research

What makes a hypothesis valid? (2)

Testable, and able to be proven wrong

To formulate a hypothesis, it means:

writing out an expectation of what’s going to happen

What happens to an invalid hypothesis? (2)

Modified/replaced, then retested

What is an independent variable?

The variable the scientist changes

What is a dependent variable?

The variable that's measured/observed

What is a controlled variable?

The variable kept the same

Independent variable: which axis on a graph?

X

Dependent variable: which axis on a graph?

Y

Memory trick: independent vs. dependent? (say trick then explain the two)

Dependent "depends" on independent; independent is what you change, dependent is what you measure

Memory trick: finding all 3 variables in a problem?

Changed = independent, measured = dependent, kept the same = controlled

Scenario: 100 seeds — 50 get 25 mL water daily, 50 get none; sunlight, temp, soil, and plant type are the same for all.
Identify the independent, dependent, and controlled variables (4).

Independent: water. Dependent: seed germination. Controlled: sunlight, temperature, soil, plant type

Seed experiment: what are the controlled variables?

Sunlight, temperature, soil, plant type

Why use a large sample size?

Avoids skewed results from one defective subject

Why repeat experiments multiple times?

Confirms results, builds confidence in data

What is peer review?

Other scientists review data before publication

Why is peer review important?

Ensures only reliable data gets published

Seed data: 27 germinated w/ water vs. 5 without — what's the conclusion?

Water is necessary for germination