How many search sets can I create on Dialog and what is the character space limit?

The ProQuest Dialog search engine is optimized to deliver the most precise retrieval from our specialized and diverse pharmaceutical, engineering, patent, and news & trade information.

As with most search engines, the user entered syntax is not the actual language used to query the various information types.

For example, we expand queries to accommodate search limits such as “human” to map to additional terms like male, female, child, adult, adolescent, and other terms that would include human studies.
In addition, based on user preferences, we deliver term variants such as US and UK spelling of terms, plurals, comparatives (taller), and superlatives (tallest).  

Instead of imposing arbitrary system limits based on character spaces or size of query, we allow users to take full advantage of our search engine by creating as many search steps or sets as they want. 

In a few cases, very complex or lengthy queries will reach system limits based on the type of query, the content being searched, and the search preferences set by the user.
In those cases, our team of expert searchers can assist users to optimize their queries, so they will not reach system limits while still providing the most precise retrieval for their research task.

The Dialog customer support team can be reached directly by email at