1.3: Scientific Thinking & Processes Key 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).

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

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. 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. 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. Principle: A concept based on scientific laws and axioms (rules assumed to be present, true, and valid) where general agreement is present. Fact: An observation that has been repeatedly confirmed.