Analysing the wording of the NPS question

NPS (Net Promoter Score) is a popular way to measure customer satisfaction. The NPS score is supposed to correlate with growth and as such of course appeals to management teams.

The idea is simple, you ask the customer how likely he or she is to recommend your product/service to others on a scale from 0 to 10. Then you calculate the score by subtracting the sum of zeros to sixes from the sum of nines and tens. If the score is positive it is supposed to indicate growth, if it is negative it is supposed to indicate decline.

My employer is a news company publishing newspapers and sites mainly in swedish (some finnish too). Therefore we mainly use the key question in swedish, i.e. Hur sannolikt skulle du rekommendera X till dina vänner? This wording, although an exact mach to the original (How likely is it that you would recommend X to a friend?) seems a little bit clumsy in swedish. We would prefer to use a more direct wording, i.e. Skulle du rekommentera X till dina vänner? which would translate into Would you recommend X to a friend? However, we were a bit hesitant to change the wordin without solid proof that it would not affect the answers.

So we decided to test it. We randomely asked our readers either the original key question or the modified one. The total amount of answers was 1521. Then, using R and the wilcox.test() function, I analysed the answers and could conclude that there is no difference in the results whichever way we are asking the question.

There is some criticism out there about using the NPS and I catch myself wondering every now and again if people are getting too used to the scale for it to be accurate any more. Also, here in Finland there is a small risk that people mix the scale with the scale 4-10 which is commonly used in schools and therefore apply their opinions to their years old impression about what is considered good and what is considered bad. I’d very much like to see some research about it.

Nevertheless, we are nowaday happily using the shorter version of the NPS key question. And have not found any reason why not to. Perhaps it could be altered in other languages too?




Leave a Reply


You are commenting using your account. Log Out /  Change )

Google+ photo


Twitter picture


Facebook photo


Connecting to %s