Answer:
condition
Step-by-step explanation:
An experiment can be defined as an investigation which typically involves the process of manipulating an independent variable (the cause) in order to be able to determine or measure the dependent variable (the effect).
This ultimately implies that, an experiment can be used by scientists to show or demonstrate how a condition causes or gives rise to another i.e cause and effect, influence, behavior, etc in a sample.
On the other hand, an observational study can be defined as a type of study in which a researcher observes and measures the effect of a diagnostic test, risk factors, or treatments on individuals without intervening, changing or manipulating who are or aren't exposed to it (controlled conditions).
Hence, the main purpose of doing an experiment over an observational study is to learn whether a certain condition causes a certain response.
Cause and effect can be defined as the relationship between two things or events in which an occurrence of one (cause) leads to the occurrence of another (effect).
