Chapter 10
steps to develop a multi-item scale
1. develop the construct 2. develop the theoretical definition 3. develop an operational definition 4. develop the multi-item scale 5. evaluate scale reliability and validity 6. apply the scale and accumulate research findings
Noncomparitive Scale
One of the two types of scaling techniques in which each stimulus object is scaled independently of the other objects in the stimulus set.
sematic differential scale
a 7-point rating scale with end points associated with bipolar labels that have semantic meaning. respondents make the blanks that best indicate how they would describe the object being rated. Data produced interval data and analyzed using profile- mean median and mode values calculated and plotted
Continuous rating scale
a measurement scale in which respondents rate the objects by placing a mark at the appropriate position on a line that runs from one extreme of the criterion variable to the other. vertical or horizontal. points may be brief descriptions or numbers. sometimes referred to as graphic rating scales Ex. reaction to TV commercials
Itemized Rating Scales
a measurement scale that has a number and/or brief descriptions associated with each categories are order in terms of scale position. categories typically are arranged in some logical order and respondents are required to select the categories that best describes their reactions. Possess characteristics of description, order, and distance.
Likert Scale
a measurement scale with five response categories ranging form "strongly disagree" to "strongly agree", which requires the respondents to indicate a degree of agreement or disagreement with each of a series of statements related to the stimulus object. * most widely used
reliability and validity
a multi-item scales should be evaluated on these things
physical form
a number of options should be tried and the best one selected. How the scale is actually presented - vertical or horizontal, boxes, lines, units
forced rating scale
a rating scale that forced the respondents to express an opinion because no opinion is not provided
multi-scale item
a scale consisting of multiple items, where an item is a single question or statement to be evaluated
Stapel Scale
a scale of measuring attitudes that consist of a single adjective in the middle of an even numbered range of values. (-5 to +5) respondents not allowed a neutral response. indicate how accurately or inaccurate the adjective described the object.
balanced scale
a scale with an equal number of favorable and unfavorable categories
construct
a specific type of concept tat exists at a higher level of abstraction than of everyday concepts.* characteristic being measured
test-retest reliability
an approach for assessing reliability in which respondents are administered identical sets of scale items at two different times under as nearly equal conditions as possible *higher correlation coefficient the greater the reliability
verbal description
an argument can be made for labeling all or many scale categories. descriptions should be located as close to the response categories as possible. * strength adjectives
disadvantages of staple scale
confusing and difficult to apply
disadvantages of sematic differential scale
difficulty determining the appropriate bipolar adjectives required to construct the scale.
Advantages of continuous rating scale
easy to construct easily implemented on the interned
advantages of staple scale
easy to construct and administer over telephone
Advantages of the Likert Scale
easy to contract and administer and understand
systematic error
error that affect the measurements in a consistent way and represents stable factors that affect the observed score in the same way each time the measurement it made.
random error
error that arises from random changes that have a different effect each time the measurement is made.
odd vs. even number of categories
if neutral or indifferent scale response is possible for at least some of the respondents, an odd number of categories should be used. `
disadvantages of the Likert Scale
more time consuming- respondents have to read the entire statement rather than a short phrase
6 factors when constructing the itemized scales
number of categories balanced vs. unbalanced odd vs. even # of categories forced and nonforced verbal description physical form
Non-comparative Scale
often called a monadic scale because only one object is evaluated at one time. respondents apply their own rating standards. Consist of continuous and itemized rating scales.
disadvantages of continuous rating scale
scoring can be difficult unless computerized
sensitivity
the ability to detach subtle difference in the attitude or the characteristics being measured
reliability
the extent to which a scale produces consistent results if repeated measurements are made on the characteristic. *free of random errors * higher the association between scores the better
alternative-forms reliability
two equal forms of the scale to be constructed and then measures the same respondents at two different times using the alternate forms
advantages of sematic differential scale
versatile images. le *used in marketing research to compare brand, product, and company
number of scale categories
while there in no optimal number 5-9 categories is usually good