Before I say a few words about the scale and subsequently the item (two different entities), I want to clarify how to say his name:
Likert pronounced (he died in 1981) his name lick-urt (short i), like to lick something. Most people mispronounce it. I hope he is resting easy…
Lickert scales and Lickert items are two different things.
A Lickert scale is a multi-item instrument composed of items asking opinions (attitudes) on an agreement-disagreement continuum. The several items have response levels arranged horizontally. The response levels are anchored with sequential integers as well as words that assumes equal intervals. These words–strongly disagree, somewhat disagree, neither agree or disagree, somewhat agree, strongly agree–are symmetrical around a neutral middle point. Likert always measured attitude by agreement or disagreement. Today the methodology is applied to other domains.
A Lickert item is one of many that has response levels arranged horizontally and anchored with consecutive integers that are more or less evenly spaced, bivalent and symmetrical about a neutral middle. If it doesn’t have these characteristics, it is not a Lickert item–some authors would say that without these characteristics, the item is not even a Likert-type item. For example, an item asking how often you do a certain behavior with a scale of “never,” “sometimes, “average,” “often,” and “very often” would not be a Lickert item. Some writers would consider it a Likert-type item. If the middle point “average” is omitted, it would still be considered a Likert-type item.
Referring to ANY ordered category item as Likert-type is a misconception. Unless it has response levels arranged horizontally, anchored with consecutive integers, anchored with words that connote even spacing, and are bivalent, the item is only an ordered-category item or sometimes a visual analog scale or a semantic differential scale. More on visual analog scales and semantic differential scales at another time.