Experimental Method


Lesson 1


Short Answer


1. Define the experimental method. Describe one major way the experimental method differs from the correlational method.


The experimental method is a manipulation of an independent variable to look for an effect on a dependent variable. That is, the experimental method includes experiments to find the relationship between one dependent variable and one independent variable. Thus, the casual relationship between the dependent and independent variable can be clearly found due to the absence of the third variable. But the disadvantage is that the distorted behaviors – since there is just one dependent and independent variable, everything outside the variables are artificially kept constant.


The correlational method is different from the experimental method in this way: experimental methods can bring out the casual relationship between the dependent and independent variable, but correlational method cannot; experimental method can only draw a conclusion of dependent and independent variable response in direct proportion, inverse proportion, or no response, but correlational method can draw a conclusion showing how strong a variable responses to another.


2. Define what is meant by a positive correlation. Define what is meant by a negative correlation. Give one example of each.


A positive correlation means the correlation coefficient, r, is between 0 to +1, indicating that as one set of scores increases, a second set of scores also increases. For example: when a baby grows (age increases), its quantity of food eaten in meals increases.


A negative correlation means the correlation coefficient is between -1 to 0, saying that a set of scores goes in the opposite direction, or inversely, to the values to another score. For example, between the age of just born and 2 years old, when the baby gets older (age increases), time spent for sleeping decreases.



4. Compare and contrast the psychodynamic and humanistic models.


Psychodynamic models mean that the behaviors are driven or motivated by powerful inner forces. In this view, human actions stem from inherited instincts, biological drives, and attempts to resolve conflicts between personal needs and society’s demands. And the main purpose of it is to reduce tension.


Humanistic models state that human are active creatures who are innately good and capable to choose. In this view, the main task for humans is to strive for growth and development of their potentials.


5. Give a hypothetical example of classical conditioning. Be sure to label the unconditioned stimulus, unconditioned response, conditioned stimulus, and conditioned response.


I have several pet parrots. I hide the food bowl so that they will not keep eating all the time; I only show the food bowl when it is time for meal. Before I feed them, I always tap the food bowl for 5 times and show the food bowl with food. At first, when I tap the food bowl, they didn’t react to the tapping sound. After a long time, when I tap the food bowl, my parrots fly towards the food bowl to eat, no matter what they are initially doing or there is any food inside the food bowl.


Before the conditioning, food is the unconditioned stimulus while the flying towards the food bowl to eat is the unconditioned response (since I can’t measure their salivation). During the conditioning, the tapping sound is the conditioned stimulus while the food is the unconditioned stimulus; the action of flying towards the food bowl is the conditioned response. After conditioning, whenever I tap the food bowl, this conditioned stimulus evokes the conditioned response, making my parrots flying towards the food bowl no matter whether there is food inside.



6. Assume that you are baby-sitting your eight-year-old nephew. Give one example of positive reinforcement and one example of negative reinforcement that you might use.


Assume that my nephew needs to take an afternoon nap, and he loves candy and cartoon shows in the TV. If he can wake up compliantly from his afternoon nap on time, I give him a candy. And then he will be able to wake up compliantly on time. Since his action creates an event that I bring him some desire, and then the desire motivates my nephew to increase the probability of that behavior, this is a positive reinforcement. If he cannot wake up compliantly from his nap on time, I don’t allow him to