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An IBM 650 Program For Paired Comparisons From Balanced Incomplete Blocks-A 6-31 Design (Parcobib-6-31)

Gulliksen, Harold O.; Tucker, Ledyard R
Publication Year:
Report Number:
ETS Research Memorandum
Document Type:
Page Count:
Subject/Key Words:
Balanced Incomplete Block Spiralling, Computer Software, Paired Comparisons, Scaling


An IBM 650 program is described which obtains scale values by paired comparisons. Circular triads are computed and rank correlation methods are used in balanced incomplete block designs. The program can analyze results from a questionnaire involving 31 objects, arranged in 31 blocks or sets of six objects each, according to a balanced incomplete block design, called a 6-31 design. Subjects rank each of the six objects in a block according to a specified characteristic. From this rank ordering, a set of unique paired comparisons is obtained. A variety of data are provided for each subject and for the total group. The program can handle a maximum of 999 subjects in a single group; computer processing takes 35 seconds for each subject. The paired comparisons computations for the total group take about 15 minutes. The minimum 650 installation is required, as is the standard 80-80 board for eight ten-digit words for the 533 input-output. Detailed descriptions of input cards (format, control, and data cards) and output cards are provided. Brief instructions for machine operators are also included.

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