Which of the following describes an experiment?

An experiment is best described as a controlled method of investigation. This definition captures the essence of what an experiment entails—it is a systematic approach to testing a hypothesis or examining a specific question by manipulating variables in a controlled environment. This control allows researchers to isolate the effects of the variable being tested while minimizing the influence of other factors, leading to more reliable and valid results.

In the context of scientific inquiry, a well-designed experiment follows specific methodologies that include clear definitions of the experimental group, control group, and the variables involved. This methodological approach is fundamental in distinguishing experiments from mere observations or guesses. It enables researchers to gather quantitative or qualitative data that can be analyzed to draw conclusions based on empirical evidence.

In contrast, simple observations of nature lack the systematic approach necessary for experimentation. Similarly, theoretical explanations, while important in the scientific process, do not involve the hands-on testing of hypotheses through controlled setups. Random guesses do not utilize any methodical approach or investigation, which is essential for an effective experiment.