Author Question: Why are random assignment and experimental control two essential ingredients of an experiment? ... (Read 67 times)

michelleunicorn

  • Hero Member
  • *****
  • Posts: 565
Why are random assignment and experimental control two essential ingredients of an experiment?
 
  What will be an ideal response?

Question 2

Dr. Malic has conducted a number of experiments to assess whether playing violent videogames makes people become more aggressive. He assigns men to play very violent games for an hour a week, and women to play very violent games for three hours a week.
 
  After a month, he assesses how aggressively they behave in a frustrating situation. He has replicated this study using the same sample of Buddhist monks and nuns twelve times. Identify the major threat to internal validity and to external validity.
 
  What will be an ideal response?



carojassy25

  • Sr. Member
  • ****
  • Posts: 299
Answer to Question 1

Answer: Random assignment is the great equalizer, and ensures that groups of participants are comparable to one another before the delivery of the independent variable. Control over extraneous variables ensures that any differences on the dependent variable are due to the manipulation of the independent variable only.

Answer to Question 2

Answer: The threat to internal validity is that Dr. Malic has not used random assignment, thus he cannot be sure that he has isolated the independent variable: the amount of time playing violent video games. The threat to the external validity is that Dr. Malic used the same sample in his replications. Not only that, but his sample of clergy may not generalize to other people, especially when it comes to the behavior of aggression.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

The U.S. Pharmacopeia Medication Errors Reporting Program states that approximately 50% of all medication errors involve insulin.

Did you know?

Amphetamine poisoning can cause intravascular coagulation, circulatory collapse, rhabdomyolysis, ischemic colitis, acute psychosis, hyperthermia, respiratory distress syndrome, and pericarditis.

Did you know?

A headache when you wake up in the morning is indicative of sinusitis. Other symptoms of sinusitis can include fever, weakness, tiredness, a cough that may be more severe at night, and a runny nose or nasal congestion.

Did you know?

Disorders that may affect pharmacodynamics include genetic mutations, malnutrition, thyrotoxicosis, myasthenia gravis, Parkinson's disease, and certain forms of insulin-resistant diabetes mellitus.

Did you know?

Anesthesia awareness is a potentially disturbing adverse effect wherein patients who have been paralyzed with muscle relaxants may awaken. They may be aware of their surroundings but unable to communicate or move. Neurologic monitoring equipment that helps to more closely check the patient's anesthesia stages is now available to avoid the occurrence of anesthesia awareness.

For a complete list of videos, visit our video library