Chapter 13 - Scaling

Name 4 advantages of using a scale

1) Improved Validity 2) Improved Reliability 3) Increased level of measurement 4) Increased Efficiency in data handling

Name 5 types of scales

1) Likert Scale 2) Thurston scale 3) Semantic Differential scale 4) Guttman scale 5) Multidimensional scale

What are two things scales can involve?

1) Multiple dimensions of a variable 2) Degree to which variable is present

What are three sources of possible scale items?

1) Researchers imagination 2) Judges (field experts) 3) Target research population

Why do we use scaling in human service professions? (5 reasons)

1) Scaling provides a linkage between research and practice 2) Scaling strengthens our intake process 3) Scaling aids intervention planning during assessment 4) Scaling can help us document intervention progress 5) Scaling can be used in agency quality assurance efforts

How is a Thurston scale constructed and structured?

Constructed with equal-appearing intervals—assumes that the distance between any two adjacent points on the scale is the same. Items range from 1 (most unfavorable) to 11, (most favorable). Respondents select the item(s) with which they most agree

True or False: On a Guttman scale, there are multiple patterns of responding that will yield any given score.

False. There is only one way to respond to get each score value on the test.

Describe the process of developing a scale.

First, seek out existing scales. Either obtain or develop a possible pool of items. Eliminate any redundant, ambiguous, or inappropriate items. Pretest your scale for validity and reliability. Screen out any items based on results of pretest. Repeat the process until you have the number of items you desire on your scale.

What is a Guttman scale?

In a Guttman scale, items have an inherently progressive nature relating to the intensity of the variable being measured.

What are the pros and cons of the semantic differential scale?

Pros: 1) Requires only 4-8 adjective pairs per dimension for a reliability of .80 or higher. 2) Easy and less time consuming to construct than some other scales 3) Adjective pairs can be adapted from prior studies Con: 1) Identifying the abstract dimensions is somewhat subjective and judgmental.

What are the pros and cons of a Likert scale?

Pros: Offers a range of choices, Provides at least ordinal level measurement, Construction is straightforward Cons: A summary score loses information.

What is a semantic differential scale?

The semantic differential format presents the respondent with a stimulus, such as a person or event, that is to be rated on a scale between a series of polar opposite adjectives.

Define "Scale"

a number of items that combine to form a composite score on a variable

Name three types of response bias phenomenon.

1) response set 2) response pattern anxiety 3) social desirability effect

Name three characteristics a scale should have to be usable.

1) should have validity 2) should have range of variation 3) Should have unidimensionality (all items measuring the same variable)

What is a Likert scale?

A Likert scale consists of a series of statements, each followed by a series of response alternatives.

Thurston and Likert scales can seem similar. Contrast them.

Thurston uses interval level data. Users are generally quick to respond. Likert can possibly be interval but definitely ordinal. You get a higher reliability with fewer items. It is easy to construct.

How do you score a Likert scale and what is a Likert scale an example of?

You sum the numbers associated with each response to get an overall score. This is an example of a summated rating scale.

How is reproducibility on the Guttman scale defined?

the ability of each individual's composite score to predict exactly the items agreed and disagreed with

Define response bias.

the tendency for people's answers to questions to be influenced by things other than their true feelings, beliefs, and behaviors.