Methods of Science

control group

a group that is not exposed to the independent variable and is compared to the experimental group

controlled experiment

an experiment that tests the effects of an independent variable on a dependent variable by comparing the results to a standard or control

dependent variable

a variable that is affected or changed by an independent variable

electrical conductivity

a measure of the amount of substances dissolved in a solution, based on the solution’s ability to pass an electrical current

experiment

a controlled test designed to gather evidence for or against a hypothesis

experimental group

a group that is exposed to an independent variable; is compared to the control group

field blank

a sampling container filled with deionized water; prepared in the field by the sampler and submitted with water samples

hypothesis

proposed answer to a question that can be tested

independent variable

a variable that is changed or manipulated in an experiment

observation

information derived from using the five senses or scientific instruments

qualitative data

non-numerical or descriptive data

quantitative data

numerical data

sample size

the number of test subjects in the control group and the experimental group

scientific method

systematic method or procedure consisting of multiple steps that scientists use to answer and investigate questions about the natural world and to develop scientific theories and laws

trip blank

a sampling container filled with deionized water that is prepared by the lab and is used in the field if samples for volatile organic compounds (VOCs) are tested

variable

conditions or factors that are present in the natural world that can be changed or manipulated in an experiment