Two-Way ANOVA
Two-Way ANOVA
T-Test
One-Way ANOVA
Two-Way ANOVA
Correlation
Regression
Chi Square
Practice Problem
Stepping & Heart Rate Study: Two-way Analysis of Variance (ANOVA)
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:
1.block: step heights (0,1)
2.rate: rates of stepping (0,1,2)
3.resthr: resting heart rate (beats per minute)
4.finalhr: final heart rate (beats per minute)
Download the SPSS dataset: Stepping.sav
QUESTIONS:
Conduct a two-way ANOVA that compares the mean final heart rate for each block height combined with each rate of stepping.
1. Write the appropriate null hypotheses for the 2-way ANOVA.
2. Report and interpret your results - be specific.