How Do I Determine Correct Sample Size for a Food Quality Survey in a Restaurant?

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This topic contains 2 replies, has 3 voices, and was last updated by  Strayer 8 months, 3 weeks ago.

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    How do I determine the correct sample size for a food quality survey in a restaurant?


    Robert Butler

    You will have to provide more detail before anyone can offer much in the way of advice.
    1. What kinds of questions are on the survey? Are they yes/no, or are they Likert scale (ratings 1-5, 1-10), or are they multiple choice or are they open ended please-add-a-comment kind or is the questionnaire a combination of all of the above?
    2. Regardless of the questions – how have you vetted the questions to make sure you are not biasing the response?
    3. What do you plan to do with the results?
    4. If you have please-add-a-comment type questions – how are you going to approach their analysis?

    If you can answer these questions perhaps I or some other individual may be able to offer suggestions.



    Are you asking what proportion of diners need to respond before it’s a reasonable sample size? It’s probably the wrong question. Most people won’t do it unless they’re very pleased, or displeased, or offered a bribe such as a discount. Feedback cards (as opposed to scientific surveys) are useful for seeing trends but not for much else. As @rbutler suggested, written comments are likely to be the most valuable feedback, as opposed to waitstaff asking “did you enjoy meal?” which is almost certainly useless. If you can encourage people to write a brief comment about their dining experience, and take the time to read and make sense of these, you should get useful insight.

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