The characteristics are modality (type of stimulus), intensity (strength of stimulus), duration (length of stimulus), and location (where the stimulus occurred).

The scientist, or "operator" of the experiment, gets to determine the type of stimulus used (as long as it is within ethical bounds).

when a relationship is optional then the value of the modality is zero.

when mandatory then the modality is one.

Low modality is a word/phrase that is more uncertain or weak. High modality is when the word is expressed more certainly and stronger. For example: Will you do this please? is low modality Do this! is high modality

Low modality is a word/phrase that is more uncertain or weak. High modality is when the word is expressed more certainly and stronger. For example: Will you do this please? is low modality Do this! is high modality