Optimal Information Gathering on the Internet with Time and Cost Constraints

The World Wide Web provides access to vast amounts of information, but content providers are considering charging for the information and services they supply. Thus the consumer may face the problem of balancing the benefit of asking for information against the cost (both in terms of money and time) of acquiring it. We study information-gathering strategies that maximize the expected value to the consumer. In our model there is a single information request, which has a known benefit to the consumer. To satisfy the request, queries can be sent simultaneously or in sequence to any of a finite set of independent information sources. For each source we know the monetary cost of making the query, the amount of time it will take, and the probability that the source will be able to provide the requested information. A policy specifies which sources to contact at which times, and the expected value of the policy can be defined as some function of the likelihood that the policy will yield an a..