Why Are Words Easier to Read Across Than Down?
We rarely think about the direction in which we read. Put a word in front of us and, as English readers, our eyes naturally move from left to right.
Now write the same word vertically:
C A R E F U L
becomes
C
A
R
E
F
U
L
The word hasn't changed. But it feels different — and research suggests that, for people accustomed to reading English horizontally, it really is processed differently.
In a 2010 study published in the Journal of Vision, Deyue Yu and colleagues compared people's ability to read English presented horizontally and vertically. They found that horizontal reading was, on average, 139% faster than one form of vertical presentation and 81% faster than rotated vertical text. The researchers linked the difference to something called visual span: the number of letters a person can recognize accurately without moving their eyes.
In other words, when we read horizontally, we appear to be able to take in more of the surrounding letter pattern at once.
A follow-up study by Yu and colleagues in 2014 explored why. They found that visual crowding — the interference caused by neighboring letters — accounted for about 75% of the information loss in their visual-span measurements, compared with 19% attributable to uncertainty about letter position and 6% to declining visual acuity away from the point of fixation. The researchers concluded that crowding was the major sensory factor limiting visual span.
That has an interesting implication for word puzzles.
We don't read every letter independently
When solving a partially completed word, we're not simply examining eight individual letters one at a time. We are looking for a pattern that our brain can connect to a word.
Consider:
C A _ _ F _ L
Even with two missing letters, the pattern begins to narrow the possibilities dramatically.
The horizontal arrangement makes that entire pattern available to our normal reading machinery. Put the same letters vertically, and the visual system has to process the pattern in a direction that English readers use far less frequently.
That difference may be small for any one word. But in a puzzle where you're repeatedly trying to recognize incomplete eight-letter patterns, small differences can accumulate.
This is where CrossEights gets interesting
CrossEights happens to make this distinction part of the game.
Its 8×8 grid contains four words running across and four running down. When you press Transpose, the Across words become Down and the Down words become Across.
The puzzle hasn't changed.
The letters haven't changed.
But the orientation has.
For an experienced player, Transpose can become part of the natural solving rhythm:
Solve. Transpose. Solve. Transpose.
A solved word provides letters that help reveal another word. Transposing then puts that newly developing word into the horizontal orientation that English readers are accustomed to processing.
The button doesn't provide new information. It changes how the existing information is presented.
And that's what makes it interesting beyond CrossEights.
When we're stuck on a problem, we often assume we need more information. Sometimes we simply need to reorganize the information we already have.
The research on horizontal and vertical reading doesn't prove that an Across word in a word puzzle is always easier to solve than a Down word. But it does give us a reason to take the difference seriously: our visual system is better practiced at processing horizontal strings of letters, and our ability to take in multiple letters at once is affected by orientation.
Sometimes the answer doesn't change.
The way you look at it does.