Assignment: Hypothesis Testing and Critical Evaluations
1. A cognitive psychologist was asked to evaluate two new educational interventions (A & B) to determine which one is the best for improving learning. The researcher recruited 30 volunteer undergraduates to serve as participants. All of the participants learned about two topics, each using a different intervention (A & B). To control for the possible effects of some extraneous variables, the teacher and classroom setting was held constant. Similarly, in attempt to control for order effects, all participants experienced the interventions in the same sequence: A and B. Finally, in attempt to avoid fatigue effects, all participants learned the first topic at 9am and the second topic at 1pm, allowing for plenty of rest in-between. Two weeks later a final test was administered for information related to both topics. Participants performed significantly better in the intervention A condition (85%) than in the intervention B condition (75%).
a) Identify the independent variable
b) List the levels of the independent variable
c) Identify the dependent variable
d) Evaluate any conclusions that are drawn
e) Point out any serious problems with the design of the study and how these problems could be corrected (e.g., internal validity, construct validity, external validity)
Format your assignment according to the following formatting requirements:
1. The answer should be typed, double spaced, using Times New Roman font (size 12), with one-inch margins on all sides.
2. The response also includes a cover page containing the title of the assignment, the student's name, the course title, and the date. The cover page is not included in the required page length.
3. Also include a reference page. The Citations and references should follow APA format. The reference page is not included in the required page length.
2. A memory researcher advertised in the newspaper for individuals who were diagnosed with clinical depression, offering $200 to individuals who would try one of two new autobiographical memory programs designed to alleviate the symptoms of depression. After volunteering for the study, individuals were randomly assigned to one of two conditions: a think-of-positive-future-events condition, or a think-of-positive-past-events condition. Individuals in both groups then recorded three events in their diary every day for two months. Twenty participants began in each condition, and 18 and 12 participants finished in the two conditions, respectively. Two months later, only 50% of the participants who finished the program in the future group were still depressed, whereas 75% of the participants who finished the program in the past group were still depressed. Statistical analysis indicated that this difference was significant. Thus, the researcher concluded that the future program was more effective than the past program.
a) Identify the independent variable
b) List the levels of the independent variable
c) Identify the dependent variable
d) Evaluate any conclusions that are drawn
e) Point out any serious problems with the design of the study and how these problems could be corrected (e.g., internal validity, construct validity, external validity)
3. A psychologist, Dr. Buzz, investigated the relationship between caffeine intake and memory ability. On the day of his experiment, the first eight participants to arrive at the testing room were assigned to a high-caffeine condition, in which each participant consumed 36 ounces of Red Bull. The next eight participants to arrive were assigned to a low-caffeine condition, in which each participant consumed 12 ounces of Red Bull. The final participants to arrive were assigned to the no-caffeine condition and were given nothing to drink. After the participants in the high- and low- conditions had finished their drinks, participants in all three groups studied a list of 50 words presented on a screen for 3 minutes. Then, following a one-minute delay, participants were asked to recall as many words as they could from the presentation. Dr. Buzz found that participants in the high-caffeine condition recalled significantly more words than participants in the low-caffeine condition, who in turn recalled significantly more words than participants in the no-caffeine condition. Dr. Buzz thus concluded that consuming caffeine improves memory.
a) Identify the independent variable
b) List the levels of the independent variable
c) Identify the dependent variable
d) Evaluate any conclusions that are drawn
e) Point out any serious problems with the design of the study and how these problems could be corrected (e.g., internal validity, construct validity, external validity)
For the following Hypothesis Testing exercise you will be assigned six hypotheses/proverbs and be asked to propose ways of testing them using the experimental method.
Translation of the ideas into a testable hypotheses
Formulate operational definitions that allow you to test each hypothesis/proverb using an experimental design. Remember that the operational definitions must clearly define how each independent variable is manipulated and how each dependent variable is measured. They should capture the meaning of the variables in question and the idea or theory expressed by the hypothesis/proverb (in other words, they should have high construct validity).
Controls procedures
Based on how you decide to manipulate your independent variable, you will need to control for the influence of certain extraneous variables. Indicate which extraneous variables you believe would be most likely to be confounded with the independent variable and describe how you would prevent or control for their possible influence. You may limit your discussion to the variables you believe pose the most serious threat to the validity of your experiment, but you must indicate at least two potential confounding variables and describe how you would control for them.
Prediction and/or expected results
Describe verbally and illustrate with a figure the type of results that would be consistent with the hypothesis.
People are less likely to cooperate with each other when they are sleep deprived than when they are not sleep deprived
Independent Variable:
Level 1:
Level 2:
Operational Definition of IV:
Dependent Variable:
Operational Definition of DV:
Potential confounding variables and control procedures used to eliminate them:
Predicted Results:
Bad experiences are more likely to be remembered than good experiences
Independent Variable:
Level 1:
Level 2:
Operational Definition of IV:
Dependent Variable:
Operational Definition of DV:
Potential confounding variables and control procedures used to eliminate them:
Students perform better in class when they take notes using pen and paper instead of a laptop
Independent Variable:
Level 1:
Level 2:
Operational Definition of IV:
Dependent Variable:
Operational Definition of DV:
Potential confounding variables and control procedures used to eliminate them:
Bad news travels fast (proverb)
Independent Variable:
Level 1:
Level 2:
Operational Definition of IV:
Dependent Variable:
Operational Definition of DV:
Potential confounding variables and control procedures used to eliminate them:
Variety is the spice of life (proverb)
Independent Variable:
Level 1:
Level 2:
Operational Definition of IV:
Dependent Variable:
Operational Definition of DV:
Potential confounding variables and control procedures used to eliminate them:
Too many cooks spoil the broth (proverb)
Independent Variable:
Level 1:
Level 2:
Operational Definition of IV:
Dependent Variable:
Operational Definition of DV:
Potential confounding variables and control procedures used to eliminate them: