Respuesta :
Answer:
Observational study is not controlled
Designed experiment is controlled.
Designed experiment
Step-by-step explanation:
An observational study draws from a sample of a population where the independent variable is not controlled because of ethical reasons and personal interference and sometimes constraints. The researcher therefore observes the population of choice without manipulation or interference.
A designed experiment is under controlled conditions, in which the researcher manipulates variables to determine a output and it constantly inputting things to improves the final result. Designed experiment is always under controlled environments with many things being anticipated or calculated.
The designed experiment therefore allows the researcher to claim causation between an explanatory variable and a response variable
