…are the meaning of life:
Note: A glossary is included near the end of this handout defining many of the terms used throughout this report.
CPSC 681 – Topic Report
Likert Scale \lickurt\, n.
A psychometric response scale primarily used in questionnaires to obtain participant’s preferences or degree of agreement with a statement or set of statements. Likert scales are a non‐comparative scaling technique and are unidimensional (only measure a single trait) in nature. Respondents are asked to indicate their level of agreement with a given statement by way of an ordinal scale.
Variations: Most commonly seen as a 5‐point scale ranging from “Strongly Disagree” on one end to “Strongly Agree” on the other with “Neither Agree nor Disagree” in the middle; however, some practitioners advocate the use of 7 and 9‐point scales which add additional granularity. Sometimes a 4‐point (or other even‐numbered) scale is used to produce an ipsative (forced choice) measure where no indifferent option is available. Each level on the scale is assigned a numeric value or coding, usually starting at 1 and incremented by one for each level. For example:
Figure 1. Sample scale used in Likert scale questions
Named after Dr. Rensis Likert, a sociologist at the University of Michigan, who developed the technique. His original report entitled “A Technique for the Measurement of Attitudes” was published in the Archives of Psychology in 1932. His goal was to develop a means of measuring psychological attitudes in a “scientific” way. Specifically, he sought a method that would produce attitude measures that could reasonably be interpreted as measurements on a proper metric scale, in the same sense that we consider grams or degrees Celsius true measurement scales (Uebersax, 2006). From http://www.performancezoom.com/performanceszoom_fichiers/likert.gif
Suppose we are comparing the opinions of Masters and PhD students in CPSC.
Please indicate how much you agree or disagree with each of the following statements: Strongly disagree 1 1 1 Somewhat disagree 2 2 2 Neither agree nor disagree 3 3 3 Somewhat agree 4 4 4 Strongly agree 5 5 5
1. The “U of C • This is now” website is easy to use. 2. The “My U of C” website is easy to use. 3. The “Peoplesoft Student Center” website is easy to use.
1 | P a g e
CPSC 681 – Topic Report
Each specific question (or “item”) can have its response analyzed separately, or have it summed with other related items to create a score for a group of statements. This is also why Likert scales are sometimes called summative scales. For our example we will evaluate the results as a whole using descriptive statistics, and also the specific results for question 1 (see Mann‐Whitney U test section below). Individual responses are normally treated as ordinal data because although the response levels do have relative position, we cannot presume that participants perceive the difference between adjacent levels to be equal (a requirement for interval data). In practice, many researchers do treat Likert scale response data as if it were interval data; however, from a statistical standpoint this can be dangerous. For example, there is no way to ensure that participants view the difference between “agree” and “strongly agree” the same as they might view the difference between “agree” and “neutral.”
“The average of ‘fair’ and ‘good’ is not ‘fair‐and‐a‐half’; which is true even when one assigns integers to represent ‘fair’ and ‘good’!” – Susan Jamieson paraphrasing Kuzon Jr et al. (Jamieson, 2004) The raw data for our example is outlined in Table 1 below. The participant responses have been grouped according to Masters and PhD students in order to help relate this ...
Please join StudyMode to read the full document