Non-Comparative Scales: Continuous Rating ScaleContinuous Rating Scale – Respondents rate objects by placing a mark at the appropriate position on a line that runs from one extreme of the criterion variable to the other. Show
Continuous Rating Scale: Perception AnalyzerItemized Rating Scales: Likert ScaleLikert Scale – Requires respondents to indicate a degree of agreement or disagreement with each of a series of statements about the stimulus object within typically five to seven response categories. Listed below are different opinions about 7-Eleven. Please indicate how strongly you agree or disagree with each by using the following scale: NOTICE the reversed scoring of items 2,4,5, and 6. Reverse the scale for these items prior analyzing to be consistent with the whole set of items, i.e. a higher score should denote a more favorable attitude. Likert Scale: ExamplesSome Commonly Used Scales in Marketing
Itemized Rating Scales: Semantic DifferentialSemantic Differential – A rating scale with end point associated with bipolar labels that have semantic meaning. Respondents are to indicate how accurately or inaccurately each term describes the object. This part of the study measures what certain department stores mean to you by having you judge them on a series of descriptive scales bounded at each end by one of two bipolar adjectives. Please mark (X) the blank that best indicates how accurately one or the other adjective describes what the store means to you. Please be sure to mark every scale; do not omit any scale. NOTE: The negative adjective sometimes appears at the left side of the scale and sometimes at the right. This controls the tendency of some respondents, particularly those with very positive Semantic Differential Scale: ExampleMeasuring Self-Concepts, Person Concepts, and Product Concepts
blue – Rating profiles of different objects / respondents / segments. orange – Each point corresponds to a mean or median of the respective scale. Semantic profiles of shampoo brands “Herbal Magic” and “Elseve” in comparison with an ideal shampoo from consumers’ point of view blue – Ideal shampoo orange – Elseve green – Herbal Magic Itemized Rating Scales: Stapel ScaleStapel Scale – An unipolar rating scale with 10 categories numbered from -5 to +5 without neutral point (zero). Used as an alternative to semantic differential, especially when a meaningful pair of opposed adjectives is difficult to construct. Please evaluate how accurately each word or phrase describes each of department stores. Select a plus number for phrases you think describe the store accurately. The more accurately you think the phrase describes the store, the larger the plus number you should choose. You should select a minus number for phrases you think do not describe it accurately. The less accurately you think the phrase describes the store, the larger the minus number you should choose. You can select any number, from +5 for phrases you think are very accurate, to -5 for phrases you think are very inaccurate. Basic Non-Comparative Scales
Non-comparative Itemized Rating Scale DecisionsNumber of categories
Balanced vs. unbalanced
Odd/even no. of categories
Forced vs. non-forced
Verbal description
Number of Scale CategoriesNumber of categories – Although there is no single, optimal number, traditional guidelines suggest that there should be between five and nine categories. + The greater the number of scale categories, the finer the discrimination among stimulus objects that is possible – Most respondents cannot handle more than a few categories Involvement and knowledge
Nature of the objects
Mode of data collection
Data analysis
more categories for sophisticated statistical analysis, esp. correlation based ones Balanced vs. Unbalanced ScalesBalanced vs. unbalanced – In general, the scale should be balanced to obtain objective data. Balanced Scale: Extremely good Very good Neither good nor bad Very bad Extremely bad Unbalanced Scale: Extremely good Very good Good Somewhat good Bad Very bad Odd or Even Number of CategoriesOdd/even no. of categories – If a neutral or indifferent scale response is possible for at least some respondents, an odd number of categories should be used. – The middle option of an attitudinal scale attracts a substantial # of respondents who might be unsure about their opinion or reluctant to disclose it – This can distort measures of central tendency and variance – Do we want/need “contrast” in controversial attitudes? Forced vs. Non-ForcedForced vs. non-forced – In situations where the respondents are expected to have no opinion, the accuracy of the data may be improved by a non-forced scale. – Questions that exclude the “don’t know” option tend to produce a greater volume of accurate data – Are respondents unwilling to answer vs. don’t have an opinion? – Use “don’t know” or better “not applicable” option for factual questions, but not for attitude questions – Use branching to ensue concept familiarity on the respondent’s side Verbal DescriptionVerbal Description – An argument can be made for labeling all or many scale categories. The category descriptions should be located as close to the response categories as possible. – Providing a verbal description for each category may not improve the accuracy or reliability of the data vs. scale ambiguity – Peaked vs. flat response distributions To the table of contents |