The tutor brings up a curiosity from psychology.

Around 1860, a scientist named Gustav Fechner was interested in how physical input becomes mental experience – how sensation leads to perception. One of Fechner’s angles for studying that connection was the jnd – just noticeable difference.

A just noticeable difference is the quantity by which two stimuli must differ before the subject can tell them apart. An example is giving the subject two masses that are slightly different. By how much must they differ for the subject to know that one is heavier than the other?

Peoples’ typical jnd depends on what the stimulus is. However, it turns out that 1/30 of the first stimulus is a value for more than one jnd.

This is paragraph one of the two test paragraphs.

This is paragraph two; you may want to study them.

Can you notice the difference between the two test paragraphs?

I’ll be talking more about the fascinating jnd and other facets of psychology.

Source:

Weiten, Wyane. Psychology: Themes and Variations. Belmont: Wadsworth, Inc., 1992.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.