From the Data and Story Library, Cornell University (http://lib.stat.cmu.edu/DASL/)

Authorization: Free Use

Description: An experiment was conducted by students at The Ohio State University in the fall of 1993 to explore the
nature of the relationship between a person's heart rate and the frequency at which that person stepped up and down on
steps of various heights. The response variable, heart rate, was measured in beats per minute. There were two different step
heights: 5.75 inches (coded as 0), and 11.5 inches (coded as 1). There were three rates of stepping: 14 steps/min. (coded as
0), 21 steps/min. (coded as 1), and 28 steps/min. (coded as 2). This resulted in six possible height/frequency combinations.
Each subject performed the activity for three minutes. Subjects were kept on pace by the beat of an electric metronome. One
experimenter counted the subject's pulse for 20 seconds before and after each trial. The subject always rested between trials
until her or his heart rate returned to close to the beginning rate. Another experimenter kept track of the time spent stepping.
Each subject was always measured and timed by the same pair of experimenters to reduce variability in the experiment. Each
pair of experimenters was treated as a block.
 

Number of cases: 30

Variable Names:

• block:  step heights (0,1)
• rate:  rates of stepping (0,1,2)
• resthr:  resting heart rate (beats per minute)
• finalhr:  final heart rate (beats per minute)

Questions

   1.    Conduct a two-way ANOVA that compares the mean final heart rate for each block height combined with each rate       of stepping.
     a.    Write the appropriate null hypotheses for the 2-way ANOVA.
     b.    Report and interpret your results - be specific.

Monkey Motivation Study:  Two-way Analysis of Variance (ANOVA)

Description:  The data for this example comes from a behavioral study of performance. The participants are 24 monkeys. Their task is to perform an "oddity" problem. They are shown three objects, e.g., two circles and a square, the odd object has a food reward placed in a small well under the object. The dependent measure (score) is the total number of trials that they select the odd object and get rewarded. There are two independent variables reward (reward) with three levels (1 grape, 3 grapes, or 5 grapes) and drive level (drive) with two levels (1 hour of food deprivation or 24 hours of food deprivation).

Download the SPSS dataset: Monkey.sav

 1.    Conduct a two-way ANOVA that compares the mean score for each level of reward combined with each level of drive.
     a.    Write the appropriate null hypotheses for the 2-way ANOVA.
     b.    Report and interpret your results - be specific.