The Scientific Method Biology the study of life

The Scientific Method

Biology – the study of life n Science – the observation, identification, description, and explanation of phenomena (occurrences in the world around us) n Latin root for the word science – scientia – means knowledge n

Steps to the Scientific Method Make an observation n Ask questions n Form the hypothesis n Set up and experiment n Collect the data n Draw a conclusion n Make a prediction n

Scientists believe all natural phenomena in the universe have logical, verifiable explanations. n Natural phenomenon – something occurring in nature that we experience through our senses. n Scientific process – used to research and explain natural phenomena n

Making Observations and Defining the Problem The scientific process begin by observing and experimenting with the things around us. n Observations are made by using the five senses (sight, smell, touch, sound, and taste) to obtain information. n May lead to identifying problems n

Asking Questions Asking appropriate questions is the second step in solving a problem. n We are seeking logical explanations for what we observe and find ways to solve problems n

Forming the Hypothesis – a statement that gives the best response to the question and should be based on already known facts. An educated guess. n Can be developed by using inductive reasoning (the ability of a scientist to draw from knowledge and experience to make a general explanation). n

Setting Up the Experiment Scientific Experiment – gives accurate and measurable results. n Experiments should be designed to collect information to prove or disprove the hypothesis. n An experiment must be set up to examine only one condition or variable at a time. n To test the hypothesis, the experiment should have two components: a control group and one or more experimental groups. n

Control group – the part of the experiment that is designed without changing any of the variables n Experimental group – designed to test components of the hypothesis and to indicate changes which might invalidate the hypothesis n Through observations and measurements of the different groups, information is collected and recorded. When data from the control group is compared to the experimental groups, the scientist can calculate how much the variables affected the investigation. n

Independent Variable – the factors that are changed or manipulated during the experiment. These are the ones an experiment is trying to test. n Dependent Variable – Usually the factor that the experimenter is measuring or counting. This is the one that changes in response to the independent variable. n Control Variable – These are the variables that you attempt to control. Kept constant. n

Collecting Data is gathered from the observations and measurements taken during a scientific experiment. n Observations must be recorded. n Qualitative data – information that cannot be assigned a numerical value. (five senses) n Quantitative data – anything that can be expressed as a number or can be quantified. Can be organized in a data table. n

Drawing Conclusions n n n Conclusion – judgment or interference based on observation and experimentation. Drawn from the results of experiment. Results – the end product of an experiment. A scientist must perform an experiment repeatedly to determine the true outcome of it. After repeated times of getting the same results, the hypothesis may become a theory. Theory – set of related hypotheses that have been tested and confirmed many times by many scientists. It unites and explains a broad range of observations.

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