How to Convert Likert Scales

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Likert scales are scales that measure agreement with a statement in a survey. For example, a statement might be “Caravaggio was a brilliant painter,” and the survey-taker has a set of choices like “Strongly Agree,” “Agree,” “Neutral,” “Disagree” and “Strongly Disagree.” This set of choices is a Likert scale. Sometimes it is necessary to convert a Likert scale to a numeric scale for the purposes of statistical analysis.

Determine what survey items are to be reverse-scored. Not all surveys have items like this, but often enough, agreement with one item shows one direction of opinion, while agreement with another item shows the exact opposite. An obvious example would be the statements “I love rock and roll music” and “Rock and roll music is horrible.” Determine whether any of the items are matched like this, and sort them into two categories, such as “pro” and “con,” “like” and “dislike” and so on. Arbitrarily call one of these groups “forward-scored” and the other “reverse-scored.”

Count how many Likert points there are in the response set. For example, a response set consisting only of “Agree” and “Disagree” has only two Likert points.

Assign the number 1 to the most extreme “disagree” response for forward-scored items, and assign successively larger numbers to each response up to the most extreme “agree” response. For example, if you have a seven-point Likert scale, you would assign the following values to each type of response: “Strongly Disagree” = 1; “Moderately Disagree” = 2; “Disagree Slightly” = 3; “Neutral” = 4; “Agree Slightly” = 5; “Moderately Agree” = 6; “Strongly Agree” = 7.

Assign the number 1 to the most extreme “agree” response for reverse-scored items, and assign successively larger numbers to each response up to the most extreme “disagree” response. For example, if you have a 7-point Likert scale, you would assign the following values to each type of response: “Strongly Agree” = 1; “Moderately Agree” = 2; “Agree Slightly” = 3; “Neutral” = 4; “Disagree Slightly” = 5; “Moderately Disagree” = 6; “Strongly Disagree” = 7.

Tips

  • Not every survey has reverse-scored items. In case the one you are working with does not, you will do just steps 2 and 3.

References

  • A Handbook of Test Construction; Paul Kline; 1986

About the Author

Based in New York City, Mark Koltko-Rivera has been writing psychology-related articles since 1987. His articles have appeared in such journals as “Psychotherapy” and “Journal of Humanistic Psychology.” Koltko-Rivera is a Fellow of the American Psychological Association. He holds a Doctor of Philosophy in counseling psychology from New York University.

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