A hypothesis is an educated guess or idea to explain an observation or a relationship between two or more variables. It is statement of speculation or a prediction which has not been validated. Hypotheses (plural) are typically written as "if,then" statements. For example, "If I do (A), then (B) will happen." A hypothesis is also testable and one could design an experiment to support or disprove its claim. A good hypothesis always states what one expects to happen as a result of the experiment. The results of an experiment can support the hypothesis, but they can not prove it; however, the experiment can disprove the hypothesis. In everyday language, hypothesis is often interchanged with theory, but they are very different. There is some variation among the disciplines of science, but for the most part theory is an accepted standard based on extensive research, data & testing, in other words theory is a widely accepted hypothesis.
A hypothesis is an essential component of a lab report or experiment. Before performing an experiment, you should predict what may happen followed by a "why?".
A simple "formula" for a hypothesis can be:
If ____, then ____ because ____.
For example, when performing an experiment on the effect of light intensity on photosynthesis, my hypothesis could be:
If the light intensity increases, then the rate of photosynthesis will also increase because light is an essential component of photosynthesis.
The first blank will often be the manipulated variable. The second will be the predicted outcome. And lastly, the third blank is the explanation.