I am new to SUS questionnaire. I want to use five questions form SUS in my research. I am taking 3 even questions and 2 odd questions. Using questionnaire this way will it misinterpret my results. Can you please guide me how should i calculate my sus scores. Please help!!

  • Hi Sushma. May I ask why you would shorten the SUS questionnaire? The questionnaire in itself is already quite small and quick to fill in. So reducing the amount of questions, and removing it's reliability, seems odd.
    – GWv
    Commented Jan 19, 2015 at 8:57
  • I have my own questionnaire form just want to add few questions from SUS questionnaire to understand usability. Can i do this or should i use only SUS questionnaire by itself ??
    – sushma
    Commented Jan 19, 2015 at 14:27
  • I'm not an expert by all means but I do know that the SUS score has been applied, tested, and validated for a long time. Proving it's scientific worth. Cutting it up in pieces will remove it's validity, hence I wouldn't bother to calculate the score afterwards because that score is based on the questionaire as a whole. That doesn't say you can't use it as an inspiration to build your own questionnaire though.
    – GWv
    Commented Jan 20, 2015 at 7:22

2 Answers 2


As others have mentioned, picking a few questions at random from SUS isn't going to give you something that you can usefully use as a guideline.

If you're interested in specific factors then I'd take a look at Lewis & Sauro's paper on The Factor Structure of the System Usability Scale where they've done a bunch of research around that topic. That may give you some guidance on what questions you can drop depending on what you're interested in.

If you're after something shorter take a look at UMUX-LITE which is a two question test that corresponds pretty well to SUS.


You can't really. Full SUS scores depend upon all of the questions being asked. I guess you could use the standard calculations to give yourself a partial score...but that wouldn't really have much scientific worth at all. You need the full set for a proper SUS score calculation.

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