It’s Day 2 of Scale Week here in the Bunker and the excitement and anticipation is growing. Here you might learn about or refresh your knowledge on another scaling option for your survey. Like we said yesterday on Twitter, it’s like a market research Shark Week, without sharks. Check out Monday’s post on Constant Sum Scaling by clicking here.
Scale #2 – Tuesday
Semantic Differential Scaling (SDS) most commonly uses adjectives to describe opposite extremes of a concept. It is set up in a survey by using a contrast of two adjectives related to your concept you are testing (warm-cold, good-bad, easy-difficult). This is administered through a bipolar scale as seen below; let’s carry over Monday’s example involving the auto industry. In this question, we have asked the respondent to rate their attitude towards a new vehicle launched in the market this past year. All of the adjectives relate to how the respondent feels towards this new vehicle model. This is one of the most common uses for the SDS scale – new product concept testing.
Each value is assigned a rating of -3 through +3 with 0 being neutral. Although the level of measurement between each value is unknown, creating an ordinal scale here helps the respondent interpret and weigh their attitude. Typical adjectives used in this type of scale test are evaluation, potency, and activity (EPA) – such as good-bad for evaluation, strong-weak for potency, and fast-slow for activity.
A few limitations with this scale involve issues with mutual exclusivity and collective exhaustiveness. Finding the right pair of adjectives to appropriately judge the product or service is key. For example if respondents established a negative view of your product through poor customer service when dialing the help line, those negative attitudes may not be uncovered through adjective testing specifically related to the product itself. Also if you are focusing too much on one single EPA above, you may have significant overlap between adjective pairs. Is there a significant difference between someone rating their attitude on new-old versus unique-standard? It’s arguable. RMS recommends using no more than 10-12 all-encompassing pairs. Try and choose words that are clear-cut and unambiguous. A strong set of adjectives to test can be created through initial qualitative research – perhaps using a focus group.
SDSs are an integral part of concept testing for the marketing of products and services. Using adjective extremes helps the respondent communicate their attitudes to assist your research in measuring image and brand equity. We’ve also seen SDS broaden its horizons more recently by working its way into more common customer satisfaction surveys and employee surveys.