Is a survey with one question statistically valid?

Evaluate questionnaires in 5 steps: This is how you get valuable information from a survey!

The questionnaire is still the method of choice for many research projects. However, when all the answers are finally available, confusion often spreads: You want to finally evaluate the questionnaire - and quickly and correctly! But how do you evaluate a survey? In this article we show the 5 most important steps you can take to evaluate a survey.

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  • This article answers the following questions about evaluating questionnaires:

    • How do you evaluate a survey?
    • Which steps should you consider when evaluating the questionnaire?
    • How do I get a first overview of the data?
    • How do I uncover connections in my data?

    Evaluation questionnaire: structured procedure in 5 steps!

    The exact procedure to be able to evaluate a survey correctly, of course, always depends heavily on the respective questionnaire and the research questions.

    We regularly carry out professional questionnaires for many of our customers: from employee satisfaction surveys to customer surveys and brand tracking. Would you also like to benefit from our expertise in evaluating a survey? Then contact us!

    In our experience, the procedure for evaluating a questionnaire can be roughly divided into 5 steps. These steps can therefore be used as a guide if you want to evaluate a survey.

    1. Check the question

    It usually takes some time from the conception of a questionnaire and until all the answers are available. It is therefore useful to recall the actual goal of the survey. The questionnaire evaluation then succeeds much faster and more focused.

    Ideally, the problem was outlined and the research question developed before the survey. A specific research question would be, for example: "How many people in the target group are familiar with our latest product?" If the research question was not formulated beforehand, it should be done now at the latest. In any case, brief reflections should be made on the following questions:

    • Evaluation questionnaire: Which questions should the results answer?
    • What problem do you want to solve with the results of the survey?
    • Which decisions should be made based on the results?

    2. Prepare data and validate answers

    In the next step, you should first clean up and prepare the data from the survey. If you have used scales with several questions (e.g. customer satisfaction), this also includes calculating the mean value from all the questions on the scale. You should also check the data for incorrect answers (e.g. age information such as “250”). For complex data sets, you can also take advantage of our professional data preparation help at any time.

    3. Analyze the response rate

    Only in the very few cases will all people who receive the questionnaire fill it out. The proportion of completed questionnaires is also referred to as the response rate. A sufficiently high response rate is crucial for the representativeness of a survey. Therefore, you should always check the response rate. Is it significantly higher or lower than expected? In that case one should look for possible causes. How high a response rate should be depends heavily on the type of questionnaire. A telephone employee survey is z. B. usually have a higher response rate than an email customer survey. If data on previous questionnaires are available, a comparison with previous response rates is also useful.

    It is also advisable to check whether a particularly large number of participants drop out on a particular question. In this case, this question should be revised for future surveys.

    4. Get an overview

    The next step should be to evaluate the questionnaire by getting an overview of the results. The best way to do this is to use simple descriptive statistics and illustrative visualizations. This is a quick way to get a first impression of the answers.

    Evaluation questionnaire: descriptive statistics

    Statistics such as average, maximum and minimum are useful for continuous values ​​(scales, age, number of product purchases, etc.). The standard deviation can also be used to estimate how much the answers vary.

    For values ​​with groups or categories (gender, recommendation: yes / no, etc.) it is initially sufficient to simply display the frequencies of the individual values. You should calculate both the absolute frequency and the relative frequency (as a percentage).

    Evaluation questionnaire: visualizations

    For continuous values, a histogram is recommended to show the distribution of the responses. If required, the visualization can also be divided into groups here (e.g. by gender or department).

    Evaluate questionnaires: Histograms are well suited to show the distribution for continuous values

    Both the pie chart and the bar chart have proven effective for values ​​with groups. A pie chart is useful if you are primarily interested in the relative distribution of the groups. A bar chart, on the other hand, is useful if you want to read off the absolute frequency of the groups.

    A simple example of a pie chart

    The same data in a bar graph

    5. Uncover connections

    Ultimately, this step is about drawing valid conclusions from the data. This step is usually the decisive one in order to answer your question and to provide assistance for future decisions. However, basic statistical knowledge is often essential for this step! If you would like support in evaluating the questionnaire, our experts are at your disposal at any time. To clarify the possibilities, we list the most common types of analysis here:

    Comparison with previous results

    This analysis is useful if the same questionnaire has already been collected in the past. In this case, you can analyze whether the new values ​​differ significantly from the previous ones or whether the different values ​​are simply the result of random fluctuations. With sufficient data, trends can also be analyzed over longer periods of time (“Have we achieved a continuous increase in customer satisfaction over the last 5 years?”).

    Comparison of different groups

    Are employees in sales more satisfied than in accounting? Does the awareness of your product differ between people in the country and in the city? Comparisons between groups can often reveal weaknesses or strengths of the company. But target groups that are particularly interested in your company or product can also be identified in this way.

    Compare with benchmarks

    Is the Net Promoter Score (NPS) higher than the minimum standard? How does brand awareness compare to the industry standard? Comparisons with benchmarks analyze whether values ​​from the survey meet previously defined minimum standards. This can be an internally established standard or simply a comparison with the average performance in the industry.

    Relationships between factors

    With a so-called correlation analysis, connections between different factors can be determined: Is the number of overtime hours related to the satisfaction of the employee? Do customers with higher purchasing power find the design of the product more important than other customers?

    With advanced analysis methods, more complex relationships can be discovered or predictions made: Does overtime only have a negative effect if the employee does not experience sufficient autonomy in his work? How much more is a wealthy buyer willing to pay for the better design?

    Conclusion: evaluate the survey correctly through a structured approach

    So there are actually many possible answers to the question “How do you evaluate a survey?”. The optimal procedure if you want to evaluate a survey correctly always depends on the type of survey and the respective research question. With a structured approach, however, the procedure can usually be accelerated considerably and many errors can be avoided. We hope this article was able to give a first overview of the evaluation questionnaire and show the possibilities.

    Keywords: evaluation questionnaire, evaluate questionnaire, evaluate survey, evaluate survey correctly, how do you evaluate a survey?