Sleep interruptions effects on REM sleep regulation

Since most Lucid dreams occur during REM, this is interesting stuff for the people who practise the WBTB method:

“Compared with sleep interruptions that last less than 10 min, sleep interruptions that last longer than 10 min occur preferentially out of REM sleep. In both the short and long types of sleep interruptions, the duration of REM periods that ended in wakefulness were shorter than the duration of those that were not interrupted by wakefulness”.

  Umm,im not sure if i got it right.So it means that sleeping without interruptions gives us longer Rem periods?

It means sponaneous sleep interruptions that last longer than 10 minutes mostly occur during NREM sleep. The interruptions shorter than 10 minutes, mostly in REM.
In both long and short interruptions the REM periods you wake up from are shorter than the ones you do not wake up from.

So it only has an effect to the REM period previous to waking up.