Technical note: subjective enumeration of episodic events (spikes) in animal physiology experiments

Blood samples of nine sheep were taken over time and analyzed for estrone, estradiol, and progesterone. Results were plotted for each sheep, and graphs were evaluated by 26 evaluators with various previous experience. Sheep were sampled for different time periods. Repeatabilities for the number of spikes of estrone, estradiol, and progesterone recorded for sheep were variable, ranging from .019 to .547. Repeatabilities for evaluators ranged from .033 to .427, but these values decreased to < .001 to .030 when adjusted by covariance for the number of spikes possible. Results indicated that either an objective procedure for counting spikes should be used in comparable research or that evaluators should be trained in visual counting procedures to improve their repeatability.