The Net Promoter Score (NPS) means many things to many marketers but it starts with a single survey question about the interviewee’s likelihood to recommend an organization, product, service, etc. To calculate NPS, you subtract the percentage of detractors from the percentage of promoters. The idea was first published in Harvard Business Review but you may have read about it in Advertising Age, Journal of Marketing or any number of publications.
A friend asked for my thoughts about NPS recently because he was getting two different results for NPS depending on how he asked the question. One question asked, “On a scale of 1-10, how likely is it that you would recommend company X to a friend or colleague?” The scale ran from 1 (Not likely) to 10 (Very likely) with 5 described as Neutral. The scale on the second question went from 1 (Definitely would not recommend) to 10 (Definitely would recommend). No qualifiers were given for numbers 2 to 9 on the scale.
I correctly guessed which question produced higher results. Can you? In my next post I will write more about NPS because both questions were wrong.
However, I would like to focus on the art of writing survey questions. The only difference between the two questions are the scales used. The second scale was more extreme than the first. “Definitely would not recommend” is much stronger language than “Not likely”. The first scale also highlighted position 5 by using the word “Neutral” instead of the number. All the other positions on the scale had numbers. This had three consequences. First, this made it appear that 5 was the midpoint. However, On a scale from 1 to 10, the midpoint would be 5.5. Second, by replacing the number 5 with a label, it calls attention to the middle of the scale and could skew answers as a result. Third, position 5 should not have been described as neutral when in fact a 5 is considered a detractor according to the published methodology.
This real life example reiterates how difficult it can be to write good survey questions. How you ask the question can determine the answers you will receive.