Exam 12: Designing, Conducting, Analyzing, and Interpreting Experiments With Multiple Independent Variables

In the boxes below, write in a pattern of means that would reveal a main effect of type of therapy. Humnarnistic Copritive-Behavioral Control Group High Self-Esteern =10 =5 =25 Low Self-Esteern =10 =5 =5

Lola conducts a study to examine aggression. She has both men and women come to a laboratory room that is either 70 degrees or 90 degrees. Suppose she finds that overall, men were more aggressive than women. This finding illustrates a(n)

Draw a block diagram of this experiment and label it completely.

Questions refer to Table 12-4. A researcher is interested in determining just how much negative interactions with strangers affect our sense of well-being. In this example, participants completed a scale of positive affect. Later, either a pleasant or unpleasant confederate is randomly assigned to interact with each participant. At the end of the experiment, participants’ positive affect is again assessed. Positive affect scores could range from 1 (low positive affect) to 15 (high positive affect). Table 12-4 TABLE OF MEANS: TIME POSITIVE AFFECT ASSESSED BEFORE EXPERIMENT AFTER EXPERIMENT ROW M Confederate Pleasant 11.10 13.30 12.20 Demeanor Unpleasant 10.60 3.50 7.05 COLUMN M 10.85 8.40 Pop. =9.63 SOURCE TABLE SOURCE SS df MS F p Between subjects effects Confederate Demeanor 265.23 1 3705.63 420.43 .000 Error 158.65 18 8.81 Within subjects effects Time 60.03 1 60.03 18.14 .000 Confederate x Time 216.23 1 216.23 65.69 .000 Error 59.25 18 3.29 -Refer to Table 12-3. This example represents a

Does there appear to be a main effect of personality (introversion/extraversion)?

Explain in words (using APA-format) the interaction between sex of participant and tone intensity.

Example #3: A researcher wishes to examine whether people high or low in self-esteem react differently to different kinds of therapy for depression. She takes a sample of 120 people (half have high self-esteem and half have low self-esteem) and randomly assigns them to one of three conditions (humanistic therapy, cognitive-behavioral therapy, and a control group of no therapy. She records their level of depression after 3 months of therapy. Scores can range from 1 (very little depression) to 30 (extreme depression). --Name the other independent variable. a.Is this IV manipulated or not manipulated by the researcher? b.Does this IV represent independent groups or correlated groups? c.How many levels does this IV have?

Suppose a researcher analyzes the same dataset using both a two-way ANOVA for independent samples and a two-way ANOVA for correlated samples. The results will show a _______ F ratio and a _______ probability for each F ratio in the correlated-samples design.

What is the scale of measurement for the dependent variable?

What is the scale of measurement for the dependent variable?

Treatment variability in a 2 x 2 design comes from

In a factorial design, when you add a level to one of your independent variables, you add ___ group(s) to your experiment.

When the effects of one independent variable depend on the particular level of another independent variable, you have a(n)

Bob conducts a three-way totally between-groups study. Which of the following explanations of his study is correct?

Suppose a researcher finds a significant main effect of sex of participant, no main effect of temperature, and no significant interaction between the two variables. To explain this main effect, you need to discuss

Questions refer to Table 12-4. A researcher is interested in determining just how much negative interactions with strangers affect our sense of well-being. In this example, participants completed a scale of positive affect. Later, either a pleasant or unpleasant confederate is randomly assigned to interact with each participant. At the end of the experiment, participants’ positive affect is again assessed. Positive affect scores could range from 1 (low positive affect) to 15 (high positive affect). Table 12-4 TABLE OF MEANS: TIME POSITIVE AFFECT ASSESSED BEFORE EXPERIMENT AFTER EXPERIMENT ROW M Confederate Pleasant 11.10 13.30 12.20 Demeanor Unpleasant 10.60 3.50 7.05 COLUMN M 10.85 8.40 Pop. =9.63 SOURCE TABLE SOURCE SS df MS F p Between subjects effects Confederate Demeanor 265.23 1 3705.63 420.43 .000 Error 158.65 18 8.81 Within subjects effects Time 60.03 1 60.03 18.14 .000 Confederate x Time 216.23 1 216.23 65.69 .000 Error 59.25 18 3.29 -Refer to Table 12-2. Room temperature is a _______-subjects variable and participant sex is a _______-subjects variable.

What is one independent variable?

In the following study, participants were instructed to press a button on a computer keyboard as soon as they detected a tone through their headphones. Half of the time, the computer screen flashed a light at the exact moment the tone was presented and the other half of the time there was no flash of light. In addition, half of the time a sensor on the participant's arm pulsed (causing a slight tickle) at the exact moment of the tone, and half of the time the sensor did not pulse. The researchers were interested in determining the extent to which these distractions would cause participants to have delayed reaction times to the tone. The researchers measured the amount of time it took participants to press the computer button (in milliseconds). Smaller numbers indicate better performance on the task. Table 12-2 TAELE OF MEANS: ARM TICKLE TICKLE NO TICKLE ROW M Flash of Flash 784.60 627.60 706.10 Light No Flash 547.30 395.50 471.40 COLUMN M 665.95 511.55 $\text { Pop. } M = 588.75$ SOURCE TAELE SOURCE SS df MS F p Flash of Light Arm Tickle 550840.90 1 550840.90 223.79 .000 Light x Tickle 238393.60 1 238393.60 327.72 .000 Residual 67.60 1 67.60 0.02 .884 -What is the other independent variable?

Researchers typically use ______ IV(s) in a factorial design.

What is ex post facto research? Give an example of an experiment that utilizes one manipulated and one measured IV.