Scientific Methodology Vodcast 1.1 Unit 1: Introduction to Biology

What is Science? Science is an organized way of gathering and analyzing evidence about the natural world Science is always changing Scientific ideas are open to testing, discussion, and revision Science is a way of observing, a way of thinking, and “a way of knowing” about the world Science is a process, not a “thing” The word science also refers to the body of knowledge that scientific studies have gathered over time

What are the goals of Science? To investigate and understand the natural world To provide natural explanations for events in the natural world (it does not deal with supernatural phenomena) Science also aims to use those explanations to understand patterns in nature and to make useful predictions about natural events Scientists propose explanations that are based on evidence, NOT belief Science does not study things that cannot be tested (is a flower beautiful, is God real) Scientists aims to be objective and to avoid bias (a particular preference or point of view that is personal, rather than scientific)

The Scientific Way of Knowing… Includes the view that the physical universe is a system composed of parts and processes that interact All objects in the universe, and all interactions among those objects, are governed by universal natural laws The same laws apply whether the objects or events are large or small Scientists assume patterns in nature are consistent

What Procedures Are at the Core of Scientific Methodology? Scientific Methodology is a process scientists use to test questions in the natural world. Scientific Methodology involves: observing and asking questions Inferring and forming hypotheses conduction controlled experiments collecting and analyzing data drawing conclusions

Observing and Asking Questions Scientific investigations begin with observations (the process of gathering information about events or processes in a careful, orderly way) Observing using one or more senses to gather information (sight, hearing, touch, smell, taste) Observation leads to questions

Inferring and Forming a Hypothesis After posing a question, scientists use further observations to make inferences (a logical interpretation based on what scientists already know) Inference + creative imagination can lead to a hypothesis (a scientific explanation for a set of observations that can be tested in ways that support or reject it)

Conducting Controlled Experiments A controlled experiment (only one variable is changed, all other variables are kept unchanged, or controlled) should be used to test the hypothesis. Variables – various factors that can change It is important to control variables and test one variable at a time because if several variables are changed in an experiment, one cannot tell which variable is responsible for the results observed Independent (manipulated) variable (x axis)– the variable that is deliberately changed Dependent (responding) variable (y axis) – the variable that is observed or measured and that changes in response to the independent (manipulated) variable

Conducting Controlled Experiments Continued… An experiment is usually divided into the control and experimental groups Control Group – exposed to the same conditions as the experimental group, except for one independent variable Experiments must be repeatable When Experiments Are Not Possible It is not always possible to do an experiment to test a hypothesis (ethical considerations prevent certain experiments – humans; field studies – researchers try not to disturb animals that they are observing)

Collecting and Analyzing Data Data – information gathered from observation (evidence) Quantitative – expressed as numbers, obtained by counting or measuring Qualitative – descriptive and involves characteristics that cannot be easily measured or counted Charts and graphs are tools that help scientists organize their data Graphs (verses a data table) make data easier to recognize and understand patterns

Drawing Conclusions Scientists use experimental data as evidence to support, refute, or revise the hypothesis being tested, and to draw a valid conclusion Conclusion – interpreting data/results from an experiment Scientists Share Their Findings: Communication and sharing ideas are vital to modern science; publishing peer-reviewed articles in scientific journals allows researchers to share ideas and to test and evaluate each other’s work

The Big Picture Valid/AcceptInvalid/ Refute or Revise

What is a Scientific Theory? Theory – a well-tested explanation that unifies a broad range of observations and hypotheses and that enables scientists to make accurate predictions about new situations A theory is formulated when a particular hypothesis becomes widely accepted Theories must be repeated several times, by many different scientists, who all get the same conclusion A theory may be revised or replaced by a more useful explanation; no theory is considered absolute truth – it can be proven false in the future