Shot Length Distributions in Educational TV Programs

Thirty-two TV programs were drawn from the University of the Air lecture series. For each program the distribution of shot lengths was determined, and the mean and the standard deviation were calculated. The average shot length ranged from 14 to 67 seconds with most samples clustering about 20 seconds. The correlation coefficient between the mean and the standard deviation was 0.966, indicating the larger the mean the flatter the distribution. A compound exponential model with two parameters (McGill, 1963) was applied to fit the distributions. Agreement between the observed and theoretical distributions were fairly good with no significant difference at the 5% level in all programs except two. The reciprocals of the first parameter were linearly correlated both with the means and standard deviations with correlation coefficients of 0.977 and 0.909, respectively. The reciprocals of the second parameter, however, were not so closely related to those statistics. A practical application of this analysis to the structual classification of TV programs is discussed.