1.3: Scientific Thinking & ProcessesKey concept: Science is a way of thinking, questioning, and gathering evidence.

• Science is a process of trying to understand the world around us using critical and logical thinking to evaluate results and conclusions.

• Scientists gather evidence and share their findings with one another.

• Observation: the use of our senses, computers, and other tools to gather information about the world.• Ex.: Studying the interactions between gorillas by observing their

behavior.

Observations can be recorded as data to be analyzed• Qualitative data: Descriptions of phenomena that can include

sights, sounds, and smells.• Quantitative data: Characteristics that can be measured or

counted such as mass, volume, and temperature; Numbers

Scientists use observations and data to form hypotheses• Hypothesis: A proposed, testable answer to a scientific

question.• Formal hypotheses are usually written in an “if, then, because”

format.• If (change of IV) then (change of DV) because (why you think this

will happen).

• If I change the light bulb then my light will work because the bulb was bad and I replaced it.

• If I increase my blood pressure medicine then my blood pressure should come down because I still suffered from high blood pressure.

How do scientists test hypotheses?• The scientific method• A) Observe and ask questions that lead to a problem• B) Form a hypothesis • C) Test the hypothesis with a controlled experiment by making

observations and gathering data.• D) Analyze gathered data• E) Reject (start over at step B) or Accept your hypothesis. • F) Form a conclusion

• This is what you will do every time you conduct a lab in this class!!!!!

How do scientists test hypotheses?• Controlled experiments study the effect of independent

variables on dependent variables.• Independent variable: A condition that is manipulated, or

changed, by a scientist. Effects are measured by changes in dependent variables.

• Dependent variable: observed and measured during an experiment.• Example: Testing medication to treat blood pressure. IV:

medication dose, DV: blood pressure.

Controlled experiments• Only one independent variable should be changed in an

experiment.• Other conditions must stay the same and are called constants.• Controlled experiments must have a control group –

everything is the same as the experimental groups but the independent variable is not manipulated.• Example: When testing blood pressure medication, control group

receives none of the active ingredient.• A large number of test subjects or trials is ideal.

Other important science terms• Inference: A conclusion reached on the basis of evidence and

reasoning. (Ex: you make an inference when you use clues to figure something out). Ex: Murder mystery book

• Law: A law that generalizes a body of observations. At the time it is made, no exceptions have been found to a law. It explains things but does not describe them; serves as the basis of scientific principles. (Ex: Law of Gravity, Newton’s Laws of motion).

• Theory: A proposed explanation for observations and experimental results that is supported by a wide range of evidence – may eventually be accepted by the scientific community. (Ex: Big Bang Theory, Evolution & Natural Selection)

• Principle: A concept based on scientific laws and axioms (rules assumed to be present, true, and valid) where general agreement is present. (Ex: Buoyancy Principle)

• Fact: An observation that has been repeatedly confirmed.