Test-site evaluation of the Instructor's Computer Utility/Programing Language of Interactive Teaching (ICU/PLANIT) was conducted. Goals included: 1) analysis of the operation of ICU/PLANIT; 2) development of two PLANIT. Modifications were made in a distrubuted version, cost analyses were in man hours and quantities of machine resources consumed, and performance was measured in response time and machine resources consumed. Preliminary results included the findings that: 1) ICU/PLANIT is machine independent; 2) PLANIT can be quickly and inexpensively installed with medium or large scale hardware; 3) PLANIT does not show a negative effect on the throughput of jobs in the host environment; 4) computer operational costs of PLANIT are not prohibitive; 5) response time under the one-copy-per-user version is poor with only one interactive job in core and in this situation demands are low on the central processor (CP) but high on the peripheral processor; and 6) authoring demands more CP time but less input/output than student use, although the costs of each are almost equal. (PB)