The National Capital FreeNet (NCF) in Ottawa Canada is one of the largest and most successful community online services in the world. An examination of this system may provide valuable information for planning future services. A survey was completed by 1073 NCF users and the results indicate that the NCF users are not a specialized group in the community. Although there is a large gender imbalance, they are not exclusively male (especially when compared to other similar systems). There is a broad range of ages represented on the system, and a wide variety of education levels. Income levels for NCF users, especially household incomes, are quite comparable to the local region. NCF users are not necessarily highly experienced in computers or computer networks. In areas where there are discrepancies with the local regional data, data from other studies suggests that the NCF is less extreme than other comparable systems. NCF users are quite satisfied with their system. Their levels of satisfaction are not strongly related to the demographic variables measured here, but the amount of computer experience seems to be the strongest factor (in the negative direction).

One need not create a natural language understanding system in order to create a hypertext data base that can be traversed with unconstrained natural language. The task is simplified because the computer creates a constrained context, imposes a non-negotiable topic, and elicits simple questions. Two small hypertext data bases describing the authors' organization and the terms and rules of baseball were implemented on an IBM PC. When ten untrained people were allowed to search through these data bases, 59 per cent of their queries were answered correctly by the first data base and 64 per cent by the second.

Food-deprived pigeons were exposed to fixed-interval food reinforcement schedules in test chambers in which water or grit was available. The intermittent food schedule did not induce reliable excessive consumption of either water or grit. This finding does not replicate an earlier report by Shanab and Peterson (1969) of schedule-induced polydipsia in the pigeon and adds another instance to the growing list of boundary conditions for schedule-induced phenomena.

The earlier two-sample procedure of Feldt [1969] for comparing independent alpha reliability coefficients is extended to the case ofK ≥ 2 independent samples. Details of a normalization of the statistic under consideration are presented, leading to computational procedures for the overallK-group significance test and accompanying multiple comparisons. Results based on computer simulation methods are presented, demonstrating that the procedures control Type I error adequately. The results of a power comparison of the case ofK=2 with Feldt's [1969]F test are also presented. The differences in power were negligible. Some final observations, along with suggestions for further research, are noted.

Pigeons were exposed to an observing-response procedure in which pecks on an observing key converted the prevailing mixed variable-interval extinction schedule of food reinforcement into the corresponding multiple schedule for a brief period of time. During some sessions, additional food reinforcement was concurrently presented. Introducing additional food reinforcement attenuated the rate of pecking the observing key. This result shows that the inhibiting effects of concurrent reinforcement are quite pervasive.