A graduate student measured the heart rote
5 (tji:cjl:,
per minute, or bpm) of a set of subjects riding at 5, 7,
and 9 miles per hour [mph) at a minimal work load on
a stationary bicycle. Fifteen subjects rode at increas-
UA .w- ing speeds for 2 minutes at each of the three rates. The
c
2 mean values for the 15 subjects at the end of each 2-
8 minute exercise bout were determined to be 120 bpm
5 z at 5 rnph, 130 bpm at 7 mph, and 150 bpm at 9
o mph. Is there a significant HR difference among the
speeds? Simple analysis of variance assumes that the three groups are
independent (that is, they are separate subjects). However, the data in this
study are not independent because each mean is based on the same 15
subjects. Using the same subjects in repeated-measure research designs
produces a relationship (correlation) among the three scores. To analyze
this type of data, we must account for this relationship. In this chapter we
learn to apply analysis of variance in a repeated-measure design.