Study Tool: Babbie Ch. 6 important points of scales and indexes

Scales vs. Indexes

Indexes: a composite measure that summarizes and rank-orders several specific observations or attributes and represents some more general variable.

Scales: assign scores to patterns of responses, to show that some items reflect a relatively weak degree of the variable while others reflect something stronger. Generally more specific than indexes.

Types of scales:

Thurstone Scale- judges assign scores to variable indicators, and the indicators with the greatest amount of agreement are used to gauge or indicate a persons level or amount of whatever variable is being studied.

Likert Scaling- provides statements about a certain topic with choices such as, “agree, strongly agree, disagree, strongly disagree” and assigns relative intensities to the meaning of each selection.

Semantic Differential- a questionnaire format in which the respondent is asked to rate something in terms of two opposite adjectives, using qualifiers such as, “very, somewhat, neither, very much”.

Guttman Scaling- based on the idea that anyone who gives a strong indicator of some variable will also give the weaker indicators. Used to summarize several discrete observations and to represent some more-general variable.