I came across through another UXSE question the idea of customer satisfaction index used in businesses as a means to improve products and services. It seems that the gold standard is the American Customer Satisfaction Index (ACSI), and looking at their website in more detail seems to suggest that it is a combination of qualitative and quantitative measures used to create an index that can be used to compare between businesses that also use the index (much like SUS).

What was interesting about the model which the index is based on is the fact that they tried to measure perception against actual outcome, which to me is like comparing research at early stages of product concept to the user testing done at the later stages of product development. Is there a clear overlap between what the ACSI tries to achieve and the user research and testing that we do in UX?

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image source: http://www.theacsi.org/about-acsi/the-science-of-customer-satisfaction

  • Not sure that ASCI is the 'Gold Standard'. Something like Net Promoter Score (NPS) appears to be more widespread/international.
    – Midas
    Commented Mar 29, 2016 at 9:51
  • @Midas I have found NPS good for general comparison but difficult to use if you want to identify specific areas for improvements, at least in the way it is commonly applied in marketing rather than for user research and testing. Perhaps you know something about a better way to use NPS?
    – Michael Lai
    Commented Mar 29, 2016 at 21:42

1 Answer 1


Short answer is they compliment each other, but ACSI is not about usability, although the usability of something could influence the ACSI score, but I doubt anyone has found a correlation.

There is clearly a small overlap between the ACSI approach and usability research approach, e.g. at a high level gathering qualitative and quantitative measures, but the ASCI measures other things which are not related to usability. However, the things ACSI measures could be useful to a usability professional because it is still revealing things about the user and what they think. Also it is probably not recognised outside the USA.

Usability research and testing is all about studying a human interacting with software to perform some task. Your usability goal is to assess whether that software is helping or hindering that user and their goal.

NPS is a red herring - it has its value but this only measures loyalty.

SUS is more useful from a usability perspective but it only measures user perceptions of usability (FYI I always ask test participants to complete SUS quetionnaire at the end of a test).

However, there is more to measuring usability than questionnaires which create a score.

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