Environment management with the help of Geo-spatial Technology is better way...

There are some published studies examining 5 vs 7 pt Likert scales:

Egs.,

Dawes, John. "Do data characteristics change according to the number of scale points used? An experiment using 5-point, 7-point and 10-point scales." International journal of market research 50, no. 1 (2008): 61-104.

Korkut Altuna, Oylum, and F. Müge ARSLAN. "IMPACT OF THE NUMBER OF SCALE POINTS ON DATA CHARACTERISTICS AND RESPONDENTS' EVALUATIONS: AN EXPERIMENTAL DESIGN APPROACH USING 5-POINT'AND 7-POINT LIKERT-TYPE SCALES." Journal of Faculty of Political Science 55 (2016).

Perhaps the most interesting one is the following, which used data collected with 4 different Likert scaled instruments, all of which indicated similar results:

Leung, Shing-On. "A comparison of psychometric properties and normality in 4-, 5-, 6-, and 11-point Likert scales." Journal of Social Service Research 37, no. 4 (2011): 412-421.

This depends on the details you want to give. I suggest 5 point is okay as it is small enough for ease of statistical analysis and large enough to accommodate environmental issues you are dealing with.

Dear Michael J. Lynch Sir,

I had gone through the article ("Do data characteristics change according to the number of scale points used? An experiment using 5-point, 7-point and 10-point scales." International journal of market research 50, no. 1 (2008): 61-104." ) referred by you, sir. I have the following doubts:

Regards,

Hoshiar Mal

Dear dr Hoshiar Mal

I have published an article in this Journal. My advice as a statistician is to use the 5 points Likert scale. This journal prefers clear and simple methods used in proper way. It is easier to change the qualitative method to quantitative when you use a simpler Liker scale. I offer you my help in preparing the paper if you are interested.

Greetings from Poland

I’ve been using a 7-point scale. There are literature about this choice.

Dear Adam Sulich,

what is the rationale behind using 5 point scale? Kindly elaborate..

Regards,

Hoshiar, India

Dear Hoshiar Mal

if you put 5 point scale:

0 - no answer

1- totally disagree

2- disagree

3- partially disagree/ partially agree

4- agree

5 - totally agree

can you please develop it into 7 point scale? What is the difference between totally disagree and mostly disagree and disagree?

Dear Adam Sulich ,

1 - Strongly Disagree

2- Disagree

3- Somewhat Disagree

4- Neutral

5- Somewhat Agree

6- Agree

7- Strongly Agree

I suggest this literature about the Likert scale.

7-point scales are slightly better

The short answer is that 7-point scales are a little better than 5-points—but not by much. The psychometric literature suggests that having more scale points is better but there is a diminishing return after around 11 points (Nunnally 1978). Having seven points tends to be a good balance between having enough points of discrimination without having to maintain too many response options. So what are the consequences of this?

Fonte: http://www.measuringu.com/blog/scale-points.php

In current practice, most rating scales, including Likert-type scales and other attitude and opinion measures, contain either five or seven response categories (Bearden, Netmeyer, & Mobley, 1993; Peter, 1979; Shaw & Wright, 1967).

FIVE – POINT

A 5 - point Likert-type scale was used to increase response rate and response quality along with reducing respondents’ “frustration level” (Babakus and Mangold 1992). Source Buttle, F. (1996). SERVQUAL: review, critique, research agenda. European Journal of marketing, 30 (1), 8-32.

A few researchers have, however, reported higher reliabilities for five-point scales (Jenkins & Taber, 1977; Lissitz & Green, 1975; McKelvie, 1978; Remmers & Ewart, 1941),

A five-point scale rather than a seven-point scale was chosen for a number of reasons, one being that it became possible to compare reliability coefficients with other research using five-point Likert Scales. Saleh, F., & Ryan, C. (1991). Analysing service quality in the hospitality industry using the SERVQUAL model. Service Industries Journal, 11(3), 324-345.

Cox (1980) concluded that the ideal number of item alternatives seemed to be centered on seven, with some situations calling for as few as five or as many as nine. Also of importance was that an odd number of alternatives, i.e., allowing for a neutral response, were preferable. Cox III, E. P. (1980). The optimal number of response alternatives for a scale: A review. Journal of marketing research, 407-422.

Previous research has found that a five-point scale is readily comprehensible to respondents and enables them to express their views (Marton-Williams, 1986).

The literature suggests that five-point scale appears to be less confusing and to increase response rate (Babakus and Mangold, 1992; Devlin et al., 1993; Hayes, 1992). It has also been suggested that a five-point scale is more appropriate for European surveys (Prentice, 1998). Source Bouranta, N., Chitiris, L., & Paravantis, J. (2009). The relationship between internal and external service quality. International Journal of Contemporary Hospitality Management, 21(3), 275-293.

With a Five - point scale, it is quite simple for the interviewer to read out the complete list of scale descriptors (‘1 equals strongly disagree, two equals disagree …’). Dawes, J. G. (2008). Do data characteristics change according to the number of scale points used? An experiment using 5 point, 7 point and 10 point scales. International journal of market research, 51(1).

SEVEN – POINT

Symonds (1924) was the first to suggest that reliability is optimized with seven response categories, and other early investigations tended to agree (see Ghiselli, 1955, for a comprehensive review of early research). Source Colman, A. M., Norris, C. E., & Preston, C. C. (1997). Comparing rating scales of different lengths: Equivalence of scores from 5-point and 7-point scales. Psychological Reports, 80(2), 355-362.

Miller (1956) argued that the human mind has a span of absolute judgment that can distinguish about seven distinct categories, a span of immediate memory for about seven items, and a span of attention that can encompass about six objects at a time, which suggested that any increase in number of response categories beyond six or seven might be futile. Colman, A. M., Norris, C. E., & Preston, C. C. (1997).

Lewis (1993) found that 7-point scales resulted in stronger correlations with t-test results. Lewis, J. R. (1993). Multipoint scales: Mean and median differences and observed significance levels. International Journal of Human-Computer Interaction, 5(4), 383-392.

Seven-point Likert scales appear to be more suited to electronic distribution of usability inventories. Finstad, K. (2010). Response interpolation and scale sensitivity: Evidence against 5-point scales. Journal of Usability Studies, 5(3), 104-110.

Research confirms that data from Likert items (and those with similar rating scales) becomes significantly less accurate when the number of scale points drops below five or above seven. Johns, R. (2010). Likert items and scales. Survey Question Bank: Methods Fact Sheet, 1.

In the light of findings, there is some support for seven-point scales, but the popularity of five-point scales seems to be less justified. Preston, C. C., & Colman, A. M. (2000). Optimal number of response categories in rating scales: reliability, validity, discriminating power, and respondent preferences. Acta psychologica, 104(1), 1-15.

Should we use a 5 or 7 point Likert scale? What's better and why? - ResearchGate. Available from: https://www.researchgate.net/post/Should_we_use_a_5_or_7_point_Likert_scale_Whats_better_and_why [accessed Nov 10, 2016].

Fonte: https://www.researchgate.net/post/Should_we_use_a_5_or_7_point_Likert_scale_Whats_better_and_why

Hoshiar Mal the choice of the scale depends on the question you are going to use and the importance of the precision of gathered information. You should test your survey questions and if your test group understands and can indicate the difference between "Strongly disagree" and "Definitely disagree" your tool is good. Then check the sample results gathered in your surveys with statistical tests. Hoshiar Mal I have to disagree to put "Neutral" or "No answer" in the middle of the scale - if you are going to show somewhere the average value (which I saw many times) in the bigger sample (more than 100 answers) all responses average values will be exactly near the "neutral value". So dear Doctor think about shifting this 0 = "no answer"/ "neutral" to the first or last position.

5 point scale allows respondents to give them fast answers, without analyzing small differences. Then you can introduce maybe more questions (remember that your survey needs to be short). In the end, all results obtained in the survey need to be encoded for a statistical program.

I’ve been adopting a seven point scale. There are studies that evidence better results from seven point Likert scale.