Calkins and a colleague kept journals of their dreams, recording each one upon awakening. She collected a total of 375 dream reports, each of which she analyzed and “coded” for several categories of content and then tabulated to determine which elements appeared most often. She found, for example, that the content of these dreams was routinely characterized by realistic settings, lots of familiar characters (“the dream world is well peopled”), mostly negative emotions, a surprisingly high proportion of rational thought and a “very striking” preponderance of visual imagery compared with other sense perceptions.

Calkins used fairly simple tools and a small data set to identify patterns in dream content, but later studies have largely confirmed these insights and extended them to new groups of people. For example, we now know that artists are more likely than non-artists to have nightmares; that children have more animals in their dreams than do adults; and that younger people are more likely than older people to have “lucid” dreams — those in which self-awareness is experienced within the dream state.

The emergence of modern digital-search technology has raised the intriguing possibility of pushing Calkins’s rather slow and labor-intensive approach to new levels of speed and sophistication. What if the coding categories she and others have used could be transformed into computer algorithms that automatically analyze not just hundreds but thousands or even millions of dreams? What new patterns and subtler dimensions of meaning might we identify?

To take the first step in exploring that possibility I have conducted several experiments in “blind analysis,” a technique developed with the help of the psychologist G. William Domhoff at the University of California, Santa Cruz.

Here’s how it works. Professor Domhoff sends me an electronic file of dream reports from a participant whose identity is hidden from me. Without reading the narratives of the dreams, I upload the file into a computer program (and database) designed for this purpose. The program enables the use of a word-search template to analyze the reports. The template includes categories for perceptions, emotions, characters and many other common features of dream content.