Research points to speed reading being a form of skimming, which is appropriate for short text but not for longer ones.

For long texts, reading more to increase vocabulary or read things you already know a lot about are the only scientifica...

Although there is an academic consensus that speed-reading decreases comprehension,

On the other hand, the same can’t be said for comprehension measurement techniques, as we can process text differently according to context.

Softwares using the RSVP (Rapid Serial Visual Presentation) method eliminate time-wasting eye movements by presenting you one word at a time.

Again, the science says this tends to have a negative impact on comprehension as the rereading is important for understanding text.

• Regressions: Quick, unconscious re-readings we do when we don't understand something.
• Saccades: Jerky, 0.1-second eye movements we use to move our fovea (center of vision) from one word to another.
• Fixations: Brief, 250-mi...

Proponents of speed reading claim sub-vocalization is a detrimental habit that can be suppressed to increase ones reading speed.

On the other hand, research indicates even using techniques to stop sub-vocalization, the mere visual recognit...

Is the inner speech readers hear in their heads as they read silently.

Unlike speech, reading and writing are "cognitively unnatural."

As a human instinct, speech doesn’t have to be taught to an infant. Writing does, because it is not a purely visual process, both reading and writing piggyback on language and speech. 

Reading involves the visual acquisition of the symbols by the eye and the cognitive processing that goes on in the background. It's an intricate dance between a number of visual and mental processes highly dependent on language.

Most educated people can read between 250 to 400 words per minute) with good comprehension. For comparison, a normal conversation produces 150 to 160 words per minute.

There are different techniques that claim to increase ones reading speed but decades of medical and psychological research indicates that said speed gain comes at the cost of understanding.