When several likert items are combined into a scale, so that there are many possible numeric outcomes, the results are often treated as intervalratio data. In an ordinal scale, responses can be rated or ranked, but. This includes not only likerttype scales but also other ordinal measures such as the rating of. To determine the minimum and the maximum length of the 5point likert type scale, the range is calculated by 5. In my opinion, the likert scale is an ordinal scale, because with this scale we cant measure the distance of two levels of scale. In relation to ordinalinterval nature of data, likert items generate the ordinal scale data and that of likert scale generates interval scale. Additionally, concerning midpoints issue, methodologically there is not any difference either using or not using midpoints in likert type measurement. Here is a typical footnote inserted in research using interval techniques with likert scales. The simple answer is that likert scales are always ordinal. A psychometric response scale primarily used in questionnaires to obtain participants preferences or degree of agreement with a statement or set of statements. It is the most widely used approach to scaling responses in survey research, such that the term or more accurately the likerttype scale is often used interchangeably with rating scale, although there are. For example, a likert scale that contains five values strongly agree, agree, neither agree nor disagree, disagree, and strongly disagree is ordinal. Should you care if your rating scale data is interval or.
Almost everyone would recognise this type of survey. The ubiquitous likert item the question above, taken from the 2007 british social attitudes survey, is an example of a likert item. The data scale is important in the determination of. Joreskog 1994 states that ordinal data describes multilevel category like likert scale. The likert scale is widely used in social work research, and is commonly constructed with four to seven points. Individual responses are normally treated as ordinal data because although the. This article talks about the characteristics of the interval scale with examples and how to create questions using various methods. When using likert scales, the researcher must consider issues such as categories of response values in the scale, size of the scale, direction of the scale, the ordinal nature of likertderived data, and appropriate statistical analysis of such data. Carifio and perla 5, 6 are among the strongest supporters for treating likerttype responses as interval data, going so far as to suggest that the likertresponses approximate ratio data. The data are from likert scales, which are ordinal, so parametric statistics cannot be used.
Both ordinal data and interval data are also a unit of measurement for data quantities. Ordinal scale has all its variables in a specific order, beyond just naming them. Measures in terms of such values as more or less, larger or smaller, but without specifying the size of the intervals. I consistently use nonnumeric symbols or labels, e. In fact, we can measure the numerical distance of 4 from 5. Structural equation modeling on likert scale data with. It is typically a five response category scale ranging from strongly disagree to strongly agree. Strictly speaking, the likert scale is an ordinal scale and cannot perform arithmetic operations. An ordinal scale is a measurement scale that allocates values to variables based on their relative ranking with. To distinguish individual items from the summated likert scale, we will refer to the individual items as likert. Use and misuse of the likert item responses and other. Meanwhile, deny 2007 mentions that likert scale can be analyzed parametrically.
Abstract the likert scale is commonly used in survey research using primary and secondary data to measure the respondent. Both data types allow the need to classify and express information. Developed in 1932 by rensis likert 1 to measure attitudes, the typical likert scale is a 5 or 7point ordinal scale used by respondents to rate the degree to which they agree or disagree with a statement table. However, these numbered measures are generally considered ordinal and violate some statistical assumptions needed to evaluate them as normally distributed, parametric data. It is usually treated as an interval scale, but strictly speaking it is an ordinal scale, where arithmetic operations cannot be conducted. Although they represent a scale of sorts when coded, they are not a likert summated scale. Likert invented the likert scale in the 1930s and it is still one of the most used methods in social, psychological, and humanfactors research. Analyzing likert data the journal of extension joe.
Pdf likert scale is applied as one of the most fundamental and frequently used psychometric tools in. While this defeats the original purpose of the likert scale approximating an interval scale it has the advantage of being easy to comprehend by management. Likert items and scales rob johns university of strathclyde 1. Interval scale offers labels, order, as well as, a specific. Analyzing and interpreting data from likerttype scales. A scale that represents quantity and has equal units but for which zero. They do make the important distinction between likert scales compared to the answers to individual questions using likerttype responses. On likert scales, ordinal data and mean values achilleas. The actual number of categories is not an important issue. Interval and ratio data are sometimes referred to as parametric and nominal and ordinal data are referred to as nonparametric. However, epistemologically it is better to use midpoints defining its meaning.
There is often a level of indecision, especially on the part of those new to research, whether to use parametric or nonparametric tests especially in the light of the discordant views outlined in the literature regarding the use of these. This is not entirely permissible from a theoretical point of view since likert scales are made up of likert items, and so have the same properties. Some researchers assume that likert scale data is interval data, yet many others assume that it is ordinal data. The likert scale originated with rensis likert 21, and has a long history of use in kinesiology research, 14, 24. That said, the distinction between ordinal and interval is based on the specific demands of the analysis being performed.
Using likert type data in social science research semantic scholar. Rather, this is an ordinal or arguably interval scale. In an ordinal scale, responses can be rated or ranked, but the distance between responses is not measurable. The intervals between positions on the scale are monotonic but never so welldefined as to be numerically uniform increments. The legitimacy of assuming an interval scale for likerttype categories is an important issue, because the appropriate descriptive and inferential statistics differ for ordinal and interval variables1,5 and if the wrong statistical technique is used, the researcher increases the chance of coming to the wrong conclusion about the. Ordinal scale measures in terms of such values as more or less, larger or smaller, but without specifying the size of the intervals. Likert scales, levels of measurement and the laws of. While almost everyone agrees that the likert rating scale provides ordinal data, the argument over whether it also provides interval data rages on. Under what conditions should likert scales be used as.
Developed in 1932 by rensis likert1 to measure attitudes, the typical likert scale is a 5 or 7point ordinal scale used by respondents to rate the degree to which they agree or disagree with a statement table. Likert scale data, on the other hand, are analyzed at the interval measurement scale. In this paper, i dissect these arguments, and show that many studies, dating back to. Nominal scale is a naming scale, where variables are simply named or labeled, with no specific order. In the hierarchy of measurement levels, the ordinal scale is usually considered the second lowest classification order, falling between the nominal and interval scales. If we can establish equal distances between ordinal numbers they become interval. You can see this firsthand on this researchgate forum, where us survey geeks and other researchers have been arguing over it since 2014. Is it interval quantitative or ordinal qualitative scale. Let us see how it can be considered as an interval scale. When multiple likert question responses are summed together interval data. Like in this example, each response in a 5point likert scale is assigned to a numeric value from 15. Most researchers would not use a 3point likerttype scale with a statistical technique requiring interval data.
The purpose of a likert scale is to identify the attitude of people towards the given stimulus objects by asking them. Both ordinal and interval data are two of the four main data types or classifications used in statistics and other related fields. In some cases, the measurement scale for data is ordinal, but the variable is treated as continuous. If the data are interval, then parametric statistics can be used. The interval scale is defined as the 3rd quantitative level of measurement where the difference between 2 variables is meaningful. Generation of an interval metric scale to measure attitude. We cant say for certain if the difference in satisfaction between a 4 and a 5 is the same as that between a 3 and a 4 on a rating scale. Likert, likerttype, and ordinalscale responses are very popular psychometric item scoring schemes for attempting to quantify peoples opinions, interests, or perceived efficacy of an intervention and are used extensively in physical education and exercise science research. Measurement quantitative and qualitative differences scale. The classic example of an interval scale is celsius temperature because the difference between each value is the same. On one hand the difference between values 4 and 6 is the same as the difference between 8 and 10, but on the other hand is it really.
Interval scales are numeric scales in which we know not only the order, but also the exact differences between the values. Editorial analyzing and interpreting data from likerttype. The likert scale analysis using parametric based structural equation modeling sem zainudin awang 1, asyraf afthanorhan2, mustafa mamat3 1,2,3 faculty of economics and management sciences,universiti sultan zainal abidin kampus gong badak, 20 kuala terengganu, malaysia. The four levels of measurement scales for measuring variables with their definitions, examples and questions. Despite the wider use of likert type data, it has limitations as well. Do research participants give interval or ordinal answers.
Reduction of data from interval to ordinal level reaction time rank intimacy rating rank 0. You can begin with analyzing and transforming your data from ordinal scale to numeric scale using mean command. Some teams may be separated by 1 win whereas others may have a 10 game gap. There is a longstanding question as to whether likert scales produce ordinal or interval data. The likert scale was named after its developer, rensis likert. Likert scale items are created by calculating a composite score sum or mean from four or more type. For example, the difference between 60 and 50 degrees is a measurable 10 degrees, as is the. The analyses of likerttype and likert scale data require unique data analysis. Ordinal x x interval x x x ratio x x x x you will notice in the above table that only the ratio scale meets the criteria for all four properties of scales of measurement. Your choice of statistical methods parametric or nonparametric will depend on whether you consider the scale to be ordinal or interval. The study concluded that in calculating reliability of likert type measurement cronbachs alpha is better to use for interval nature of likert data and ordinal alpha for ordinal nature. Likert scale, structural equation modeling sem, ordinal, interval, parametric 1. Interval scale measures in terms of equal intervals or degrees of difference but without a true zero point.
Likert scale examples for surveys iowa state university. Pdf can likert scales be treated as interval scales. Likert and likert type scale the construction of likert or likert type scale is rooted into the aim of the research sometimes the purpose of the research is to understand about the opinionsperceptions of participants related with single latent variable phenomenon of interest. An interval scale is a type of ordinal scale whereby each response is an interval on its own. By depicting the data on a scale, both types of data point out to a. A typical likert scale item has 5 to 11 points that indicate the degree of agreement with a statement, such as 1strongly agree to 5strongly disagree. An ordinal scale of measurement represents an ordered series of relationships or rank order. Is a likert scale considered interval, ratio, or nominal. Analyzing data measured by individual likerttype items.
Consider a concept that is physical in nature, say weight. Pdf the likert scale is widely used in social work research, and is commonly constructed. Introduction the likert scale is commonly used in survey research especially from social science, management. A very common question is whether it is legitimate to use likert scale data in parametric statistical procedures that require interval data, such as linear regression, anova, and factor analysis.
This video explains about the analysis steps in spss. I think, most of the time, these surveys are just ordering responses lowest to highest and not fulfilling the interval scale requirements. Likerts monograph 1932 makes it clear he never intended for the fivepoint, sevenpoint or other response alternatives to be the scale. Likerttype scales such as on a scale of 1 to 10, with one being no pain and ten being high pain, how much pain are you in today. Likert scales are widely used in social and educational research. How to analyze your likert scale data in spss youtube.
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