chapter 1.1

• observation: the action or process of closely observing or monitoring something or someone
• experimentation: the process of performing a scientific procedure, especially in a laboratory, to determine something
• hypothesis: a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation
• variable: not consistent or having a fixed pattern; liable to change
• control group: a group used as a standard against which other groups are compared in an experiment
• independent variable: a factor that is manipulated by an experimenter to test its effect on another factor (dependent variable)
• dependent variable: the variable that is measured in an experiment, such as the height of a plant
• alternative hypothesis: a statement about a difference between two variables being tested
• a good hypothesis is testable
• a hypothesis makes predictions that can be tested by observations
• support hypothesis: the hypothesis is supported by the data, but not conclusively
• reject null hypothesis: the results are so different from what would have been expected if the null hypothesis were true that it seems unlikely that the null hypothesis could be correct
• positive control: a value of the independent variable that simulates the results expected by our hypohtesis
• negative control: the value of the independent variable to see how much of the dependent variable we should expect if our hypothesis is unsupported
• confounding variable: a variable that is not controlled for in a study but affects the results
• correlation: a mutual relationship or connection between two or more things
• causation: the relationship between the cause and the effect of an event, or the relationship between the cause and the occurrence of a disease
• correlation vs causation: correlation is a statistical relationship between two variables, while causation is the relationship between a cause and an effect