Six methods for collecting the judgments of experts concerning the relative value of sets of criteria were compared for their reliability and time efficiency. The methods were ranking, rating, three versions of paired comparisons and a method of successive comparisons suggested by Churchman, Ackoff and Arnoff [Churchman, C. W., R. L. Ackoff, E. L. Arnoff. 1957. Introduction to Operations Research. Wiley, New York.]. The judgment situations used were concerned with the design of a specific air defense system and a general air defense system, and with selecting a personnel subsystem manager for a development program. In each of these three situations six criteria were comparatively evaluated by the judges. The results of these experiments showed that there were no significant differences in the sets of criterion weights derived from collecting the judgment data by any of the methods, but that ranking was by far the most efficient method. A fourth experiment was conducted to develop baseline data on the time required to make comparative judgments vs. number of items to be judged, by the ranking method and by the simplest paired comparisons method. Ranking is increasingly more efficient than paired comparisons as the number of items to be judged increases from six to 30.

Arborists maintain trees in landscapes where failure can cause damage to infrastructure. Codominant branch unions are considered less stable than lateral branch unions. Previous research has found that unions can be considered codominant when aspect ratio is greater than 0.70 when included bark is present, yet it remains unclear if this threshold is reasonable in the absences of included bark. We utilized digital image correlation to measure strain (deformation) and separation angle to failure to better understand how mechanical loads move through Acer rubrum L. (red maple) branch unions. Strain was found to be higher in the branch regions in limb failure and ball and socket failure modes and strain was greater in the branch protection zone regions of imbedded and flat failures. Strain at failure was found to decrease with increasing aspect ratio, plateauing beyond aspect ratios of 0.83. In the absence of included bark, red maple branch unions appear to become codominant at aspect ratio of 0.83. We recommend that arborists should proactively manage to keep aspect ratios lower than 0.60 and consider mitigation options as aspect ratios approach 0.70.

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The time required by judges to complete the recording of their preferences among a series of items was measured in several situations. In an experiment concerning the judgment of the relative value of six weapon system criteria, time was measured on the recording of judgments by the following methods: ranking, rating, three versions of paired comparisons, and a method of successive comparisons. In a second experiment on judging six weapon system criteria, and a third on six manager characteristics, similar time data were collected by all methods but successive comparisons. In a fourth experiment, time data were collected on recording preferences for fruits, vegetables, colors, and vacation areas when 6, 10, 20, and 30 of each were ranked, and when paired comparisons was used for 6, 10, and 20 of each. Ranking consistently is by far the most efficient of the methods tested for recording such preferences, and, as previously reported research has shown, can yield preference scales similar to the other methods.

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