In Digital reading spaces: How expert readers handle books, the Web and electronic paper, Terje Hillesund reports

Sometimes, ["Carl"] said, when working away from printers at his cottage, he urgently needs to read an article kept on his laptop. At one level on–screen reading is unproblematic; he can read through the text, understanding every sentence and paragraph. At the same time, he often gets a feeling of failing to get fully to grips with the text, that he somehow loses oversight and is unable to fence the article in, which is frustrating. When asked to expand on these utterances, he says that in order to see connections and make inferences when reading, he often needs to have several text passages or ideas present simultaneously. In printed versions, the passages are physically there on the sheets of paper, and he can flick back and forth, stick his finger in between sheets and keep several ideas in his memory at the same time; comparing, relating and thinking. He is unable to do this on the laptop; here, the text and the author’s intention somehow slip through his fingers. [emphasis mine]

This, to me, is the main problem with online/ereader reading and editing. I have been told, first when starting to edit electronically and later when reading on a Kindle, that I would develop the ability to remember where I saw something in an electronic document the way I currently remember placement of text in paper documents. To a certain extent I have developed this ability, at least for editing. I can remember some of the surrounding text, perhaps whether it was near a section head or graphic. If memory fails and I remember the phrasing, I can electronically search for what I'm looking for. Perhaps as I become better acquainted with the Kindle, I will likewise develop the ability to find a specific previously read passage, perhaps by using the bar at the bottom or the percentage-read indicator.

However, an electronic document is still not conducive to the type of comparative reading that "Carl" mentions in the above passage. One workaround when reading on a computer, whether on- or offline, is to use multiple windows or tabs to open many documents at once. This method can also be used to access different locations within the same document when reading online; however, it does not work when using various offline devices such as Adobe Acrobat Reader or Kindle for Mac.

But ereaders don't have a workaround. While I see various improvements--contrast, refresh speed, annotation capabilities--being developed for current ereaders, none of them appear to be working on the capability to allow quick flipping back and forth between passages within a book or between passages in different books. In fact, I have seen no mention of the capability being developed to allow more than one book to be open simultaneously.

Currently reading on electronic devices recreates the pre-codex days of reading from scrolls where comparative and reflective reading is impaired and comprehension less. Without some workaround or technological solution, I don't think ereaders will take over completely or even in the classroom the way many publishers and ereader sellers expect.