<P> The scientific method depends upon increasingly sophisticated characterizations of the subjects of investigation . (The subjects can also be called unsolved problems or the unknowns .) For example, Benjamin Franklin conjectured, correctly, that St. Elmo's fire was electrical in nature, but it has taken a long series of experiments and theoretical changes to establish this . While seeking the pertinent properties of the subjects, careful thought may also entail some definitions and observations; the observations often demand careful measurements and / or counting . </P> <P> The systematic, careful collection of measurements or counts of relevant quantities is often the critical difference between pseudo-sciences, such as alchemy, and science, such as chemistry or biology . Scientific measurements are usually tabulated, graphed, or mapped, and statistical manipulations, such as correlation and regression, performed on them . The measurements might be made in a controlled setting, such as a laboratory, or made on more or less inaccessible or unmanipulatable objects such as stars or human populations . The measurements often require specialized scientific instruments such as thermometers, spectroscopes, particle accelerators, or voltmeters, and the progress of a scientific field is usually intimately tied to their invention and improvement . </P> <P> I am not accustomed to saying anything with certainty after only one or two observations . </P> <P> Measurements in scientific work are also usually accompanied by estimates of their uncertainty . The uncertainty is often estimated by making repeated measurements of the desired quantity . Uncertainties may also be calculated by consideration of the uncertainties of the individual underlying quantities used . Counts of things, such as the number of people in a nation at a particular time, may also have an uncertainty due to data collection limitations . Or counts may represent a sample of desired quantities, with an uncertainty that depends upon the sampling method used and the number of samples taken . </P>

How did methods of scientific inquiry help in the search for elements