which of the following is not required for a ...

which of the following is not required for a study to be a well - designed experiment, but may offer an additional level of control?\n○ blocking\n○ treating all experimental units equally except for the treatment being applied.\n○ random assignment of experimental units to treatment groups\n○ replication

Answer

# Brief Explanations: In a well - designed experiment, treating all experimental units equally except for the treatment (control principle), random assignment of units to treatment groups (randomization), and replication (repeating the experiment) are essential. Blocking is a technique that can add an extra level of control by reducing variability within groups but is not a fundamental requirement for a well - designed experiment. # Answer: blocking