The "clicks and clunks" technique was originally introduced by Christine D. Bremer, Sharon Vaughn, Ann T. Clapper, and Ae-Hwa Kim in 2002. Read their original article here.
When it "Clicks," all is well in the world of decoding and easy comprehension. Reading is a joyful way to explore the world!
But when students encounter parts of the text that are not understood, they "Clunk!" and the reading process slows down.