likert scale [muhammad amirrul fahmi bin mukhtar]

Likert Scale“This article provides information on Likert Scale. The article are

focusing on how to use the Likert Scale and what the assumption

have to be meet in order to carry analysis. The article also

discussing on analysis method that can be use with Likert scale and

also briefing on some definition on Likert scale”

Prepared by:-

Muhammad Amirrul Fahmi Bin Mukhtar 203674

Instructor:-

Prof. Madya Dr. Bidin Bin Yatim

Table of Contents

Table of Contents

Introduction to Likert Scale_______________________________1

Sample Question Presented Using Likert Scale_______________2

Assumption in Likert Scale_______________________________4

Likert Scale Analysis____________________________________5

Advantages and Disadvantages of Using Likert Scale__________7

Summary_____________________________________________8

References___________________________________________9

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document.Testing scaling

Introduction to Likert Scale

Definition

A method of ascribing quantitative value to qualitative data, to make it amenable to statistical analysis. A numerical value is assigned to each potential choice and a mean figure for all the responses is computed at the end of the evaluation or survey.1

Used mainly in training course evaluations and market surveys, Likert scales usually have five potential choices (strongly agree, agree, neutral, disagree, strongly disagree) but sometimes go up to ten or more. The final average score represents overall level of accomplishment or attitude toward the subject matter.

History of Likert Scale

Liker Scale was invented by Rensis Likert in1932. Likert was born in Cheyenne, Wyoming. He received his doctorate from Columbia and later became the Director of the Institute for Social Research at the University of Michigan. He was an American educator and organizational psychologist best known for his research on management styles. He is also famous for developing the Likert Scale, a psychometric scale commonly involved in research using questionnaires and the linking pin model. Likert was known for his support of interdisciplinary collaborations and emphasis on using social science research to effect positive change. [2][3]

A typical Likert-like scale: " I find these guides to be useful:"

Always _____ Almost_____ Sometimes_____ Almost Never_____ Never_____

~Rensis Likert~

[1] http://www.businessdictionary.com/definition/Likert-scale.html

[2] http://www.lib.uwo.ca/programs/generalbusiness/likert.html

[3] http://www.isr.umich.edu/home/anniversary/timeline.html

Introduction to Likert Scale

In memory ~ Rensis Likert

(1903 - 1981)

http://www.isr.umich.edu/home/anniversary/timeline.html

http://www.lib.uwo.ca/programs/generalbusiness/likert.html

http://www.businessdictionary.com/definition/Likert-scale.html



Sample Question Presented Using Likert Scale

Sample question presented

Likert scale is a measurement method used in questionnaire such as student satisfaction toward library facilities.[4] They allow answers that range from such choices “strongly disagree” to “strongly agree. It is the most widely used scale in survey research. When responding to a Likert questionnaire item, respondents specify their level of agreement to a statement, for example:

1 2 3 4 5 6 7Strongly Disagree Slightly Undecided Slightly Agree StronglyDisagree Disagree Agree Agree

1. My job provides a lot of variety. _____

2. My job provides the opportunity for independent action. ____

In some cases there should not be a middle choice so that the respondents are forced to choose one side or the other. In the example below, note there are an even number of choices, rather than an odd number:

1 2 3 4 5 6Strongly Disagree Slightly Slightly Agree StronglyDisagree Disagree Agree Agree

Scoring

When the questionnaire is completed, each item may be analyzed separately or in some cases item responses may be summed to create a score for a group of items. Hence, Likert scales are often called summative scales.

There are two consideration need to be taken when determine the scoring. First, Likert Scale is arbitrary. Meaning the value assign to Likert item has no

[4] http://www.nwlink.com/~donclark/hrd/history/likert.html


http://www.nwlink.com/~donclark/hrd/history/likert.html



objective numerical basic, either in term of measuring theory or scale. The value assign is based on researcher judgement who designs the questionnaire. Typically scoring range between 2-7 with 5 or 7 being the most used.

Second, ether the ‘distance’ between each successive Likert item is equivalent, which is inferred traditionally. For example, in the above five-point Likert Scale, the inference is that the ‘distance’ between items 1 and 2 is the same as between items 3 and 4. In terms of good research practice, an equidistant presentation by the researcher is important; otherwise it a bias in the analysis may result. For example, a four-point Likert Scale–Poor, Average, Good, Very Good–is unlikely to have all equidistant items since there is only one item that can receive a below average rating. This would arguably bias any result in favor of a positive outcome. On the other hand, even if a researcher presents what he or she believes is an equidistant scale, it may not be interpreted as such by the respondent.[5] [6]

Measurement of Scales

Many researcher and statistician encounter a problem when to determine measurement of scale. There a number of articles argued and assumed do not form an interval scale. Instead, should be treated as ordinal scales and analyzed accordingly.

Brown has stated that despite all this confusion, most research based on Likert Scales and items treat them as interval scales and analyzes them as such with descriptive like means, standard deviations, and etc.

In addition, there are several research have shown that Likert Scales can indeed be analyzed effectively as interval scales. (Baggaley & Hull, 1983; Maurer & Pierce, 1998; and Vickers, 1999)

[5] Jamieson, Susan (2004). “Likert Scales: How to (Ab)use Them,” Medical Education,

Vol. 38(12), pp.1217-1218

[6] Norman, Geoff (2010). “Likert scales, levels of measurement and the “laws” of

statistics”. Advances in Health Science Education. Vol 15(5) pp625-632




Assumption in Likert Scale

Test of Scaling Assumption

There are 5 basic assumptions that must be satisfied [7]:-

Equal item variance. Items measuring the same concept should have approximately equal variances. Otherwise, their respective contribution to the total score variability would be unequal, and the computation of the total score would require standardization of items before summation.

Item internal consistency. An item should be quite linearly related to the underlying concept being measured. The item–scale correlation corrected for overlap for coefficients should be >0.3

Equality of item–scale correlations. Items in a given scale should contain approximately the same proportion of information about a concept and therefore the item–scale correlation within a scale should be roughly equal.

Item discriminate validity. An item should correlate better with its hypothesized scale than with scales measuring other concepts. The statistical significance of the difference between the item–own and item–other scale correlation was tested by Steiger’s t-test.

Reliability and interpretable scale score. The internal reliability of scale scores was measured by Cronbach’s α-coefficient (Cronbach's α). A minimal reliability coefficient should be >0.7 for group comparison. If each scale measures a unique concept, the correlation between scales should be less than their internal reliability coefficient.

[7] http://rheumatology.oxfordjournals.org/content/49/8/1495.full#ref-22

Assumption in Likert Scale

http://rheumatology.oxfordjournals.org/content/49/8/1495.full#ref-22



Likert Scale Analysis

Steven's Scale of Measurement

Likert scale data have unique data analysis procedures. To understand the options, one must start with the Steven's Scale of Measurement (Ary, Jacobs, & Sorenson, 2010). The Steven's scale consists of four categories: nominal, ordinal, interval, and ratio.[8]

In the nominal scale, observations are assigned to categories based on equivalence. Numbers associated with the categories serve only as labels. Examples of nominal scale data include gender, eye color, and race. Ordinal scale observations are ranked in some measure of magnitude. Numbers assigned to groups express a "greater than" relationship; however, how much greater is not implied. The numbers only indicate the order. Examples of ordinal scale measures include letter grades, rankings, and achievement (low, medium, high). Interval scale data also use numbers to indicate order and reflect a meaningful relative distance between points on the scale. Interval scales do not have an absolute zero. An example of an interval scale is the IQ standardized test. A ratio scale also uses numbers to indicate order and reflects a meaningful relative distance between points on the scale. A ratio scale does have an absolute zero. Examples of ratio measures include age and years of experience.[8]

Analyzing Likert Response Items

Likert scale data, are analyzed at the interval measurement scale. Likert scale items are created by calculating a composite score (sum or mean) from four or more type Likert-type items; therefore, the composite score for Likert scales should be analyzed at the interval measurement scale. Descriptive statistics recommended for interval scale items include the mean for central tendency and standard deviations for variability. Additional data analysis procedures appropriate for interval scale items would include the Pearson's r, t-test, ANOVA, and regression procedures. Table 1 provides examples of data analysis procedures for Likert scale data. [8]

[8] http://www.joe.org/joe/2012april/tt2.php


http://www.joe.org/joe/2012april/tt2.php



Table 1.Suggested Data Analysis Procedures for Likert Scale Data [8]

Likert Scale Data

Central Tendency

Variability

Associations

Other Statistics

Mean

Standard Deviations

Pearson’s r

ANOVA, t-test, regression




Advantages and Disadvantaged of Using Likert Scale

Advantages of Likert Scale

The advantageous side of the Likert Scale is that they are the most universal method for survey collection, therefore they are easily understood. The responses are easily quantifiable and subjective to computation of some mathematical analysis. Since it does not require the participant to provide a simple and concrete yes or no answer, it does not force the participant to take a stand on a particular topic, but allows them to respond in a degree of agreement; this makes question answering easier on the respondent. Also, the responses presented accommodate neutral or undecided feelings of participants. These responses are very easy to code when accumulating data since a single number represents the participant’s response. Likert surveys are also quick, efficient and inexpensive methods for data collection. They have high versatility and can be sent out through mail, over the internet, or given in person. [9]

Disadvantages of Likert Scale

Attitudes of the population for one particular item in reality exist on a vast, multi-dimensional continuum. However, the Likert Scale is uni-dimensional and only gives 5-7 options of choice, and the space between each choice cannot possibly be equidistant. Therefore, it fails to measure the true attitudes of respondents. Also, it is not unlikely that peoples’ answers will be influences by previous questions, or will heavily concentrate on one response side (agree/disagree). Frequently, people avoid choosing the “extremes” options on the scale, because of the negative implications involved with “extremists”, even if an extreme choice would be the most accurate. [9]

[9] http://psyc450.wordpress.com/2011/12/05/the-likert-scale-advantages-and-

disadvantages/

Advantages and Disadvantages of Using Likert

Scale

http://psyc450.wordpress.com/2011/12/05/the-likert-scale-advantages-and-disadvantages/

http://psyc450.wordpress.com/2011/12/05/the-likert-scale-advantages-and-disadvantages/



Summary

The data analysis decision for Likert items is usually made at the questionnaire

development stage. Where the researcher usually let their answer to be in

range of five or seven with such as choices “strongly disagree” to “strongly

agree”. There always a confusion in determine the measurement scale for likert

scale. But there are research who discover that Likert scale are best to analyze

by using interval scale. There are 5 assumption need to be meet in order to

Likert Scale to be used. Those are equal item variance, item internal

consistency, equality of item–scale correlations, item discriminate validity and

reliability and interpretable scale score. Keep in mind that once the decision

has been made, the decision on the appropriate statistics will fall into place.

Summary



References

Ary, D., Jacobs, L. C., & Sorensen, C. (2010). Introduction to research in

education (8th ed.). California: Thomson Wadsworth.

Baggaley, A., & Hull, A. (1983). The effect of nonlinear transformations on Liker

Scale. Evaluation & the Health Professions, 6, 483-491.

Brown, J. D. (2011). Likert items and scales of measurement?. Universitu of

Hawai’I, Manoa.

Jamieson, S. (2004). Likert Scales: How to (Ab)use Them. Medical Education,

Vol. 38(12), pp.1217-1218.

Maurer, J., & Pierce, H. R. (1998). A comparison of likert scale and traditional

measures of self-efficacy. Journal of Applied Psycology, 83, 324-329.

Norman, G. (2010). Likert scales, levels of measurement and the “laws” of

statistics. Advances in Health Science Education. Vol 15(5) pp625-632.

Vickers, A. (1999). Comparison of an ordinal and continuous outcome measure

of muscle soreness. International Journal of Technology Assessment in

Health Care, 15, 196-201.

Likert Scale. Retrieved on October 25, 2012, from


1946: Birth of the Survey Research Center. Retrieved on October 25, 2012,

from


References





Biography – Rensis Likert (1903 – 1981). Retrieved on October 25, 2012 from


Likert Scales. Retrieved on October 25, 2012 from


Analyzing Likert Data. Retrieved on October 25, 2012 from


Testing sealing assumption, reliability and validity of medical outcomes study

short-form 36 health surveys in psoriatic arthritis. Retrived on October

25, 2012 from


The Likert Scales: Advantages and Disadvantages. Retrieved on October 25,

2012 from

http://psyc450.wordpress.com/2011/12/05/the-likert-scale-advantages-

and-disadvantages/

References

http://psyc450.wordpress.com/2011/12/05/the-likert-scale-advantages-%09and-disadvantages/

http://psyc450.wordpress.com/2011/12/05/the-likert-scale-advantages-%09and-disadvantages/





likert scale [muhammad amirrul fahmi bin mukhtar]

Documents

sample question presented

meaningful relative distance

equal item variance

item internal consistency

health science education

item discriminate validity

interpretable scale score

choices strongly disagree