The post Ratio Scale in Research Methodology appeared first on Reading Craze.

]]>Ratio scale has order and equally distanced values between units and at the same time has an absolute zero as well. It can quantify the difference between each value and ratios can also be calculated. Though, unlike interval scale, this scale does not have negative numbers because of absolute zero. To know whether a variable can be measured on the ratio scale one should see that whether it meets all the requirements for the interval scale if it does and it has an absolute zero then it can be measured on the ratio scale.

- A ratio scale has a rational zero point where the value of the variable has no value. For example, weight and height can be measured on ratio scale because they have a real zero value. On the other hand, the temperature cannot be measured on ratio scale because a zero degree centigrade temperature does not mean that there is no heat or cold. Most of the scientific variables like height, weight, age, density, strength, time, volume, speed can be measured on a ratio scale.
- A rational zero is necessary to measure the ratio between two values of a variable, in the absence of a real zero there is no ratio. In the absence of a zero, does it make sense to say that a student who got 100 marks in mathematics has got double as compare to the one who got 50?
- A scientific variable cannot be measured precisely on nominal, ordinal or interval variable, in the absence of a ratio scale, scientific variables cannot be measured.

A wide range of all descriptive and inferential statistics can be applied on the ratio scale. All statistical analysis including mean, median, mode, variance, standard deviation, and the range can be calculated on a ratio scale. In addition, statistical tests like t-test, f-test, correlation, chi-square etc can also be calculated on ratio scale variable.

For detailed overview of the measurement scales read Types of Measurement Scales in Research

- Gideon Vigderhous,
*The Level of Measurement and Permissible Statistical Analysis in Social Research,*Pacific Sociological Review, Vol. 20, No. 1, 1977, pp. 61-72. - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3963323/
- Campbell MJ, Machin D, Wiley J.
*Medical Statistics: A Commonsense Approach,*Vol. 2. London: Wiley; 1993.

The post Ratio Scale in Research Methodology appeared first on Reading Craze.

]]>The post Interval Scale in Research Methodology appeared first on Reading Craze.

]]>- This scale has constant equal distances between each successive values.
- This scale has wide scope due to its characteristic that it can categorize the data in equal intervals.
- Mean and standard deviation can be applied to data measured using this scale. The range can also be calculated to obtain the data dispersion.

- This scale has all the characteristics of a complete measuring scale except that it does not have an absolute zero.

Selection of the right statistical technique and data analysis depends heavily on the variables to be studied and the measurement scales used in the research. Therefore, the selection of right measuring scale is crucial to the success of the research. Data that has been measured using this scale can be treated by one of the several statistical techniques including mean, standard deviation, regression, correlation, range, analysis of variance etc. Studentized range and coefficient of variation cannot be calculated because ratios have no meanings in this scale.

- Campbell MJ, Machin D, Wiley J.
*Medical Statistics: A Commonsense Approach.*Vol. 2. London: Wiley; 1993. - Stevens SS. Bobbs-Merrill,
*On the Theory of Scales of Measurement.*College Division; 1946. - Marateb H. Reza, et al,
*Manipulating measurement scales in medical statistical analysis and data mining: A review of methodologies.*Journal of Research in Medical Sciences; 2014 Jan; 19(1): 47–56.

The post Interval Scale in Research Methodology appeared first on Reading Craze.

]]>The post Ordinal Scale in Research Methodology appeared first on Reading Craze.

]]>- It sub-categorizes values in the order of their magnitude. For example, the attitude of students towards a school program can be categorized in very effective, effective and not effective. The typical 5 or 7 point Likert scale is an example of ordinal scale. The use of Likert scale is very common in social sciences.
- This scale has greater scope for psychology and other social sciences research.

- This scale sorts the data in order but it does not quantify the relationship between different sub-categories.
- Because of lack of equal distances between scale points, arithmetic and statistical operations are not possible.

The researcher can apply median and mode to ordinal scale measurements but mean and standard deviation cannot be applied. Application of median is possible because data in ordinal scale is arranged in descending or ascending order. This arrangement of data allows finding out the median of the data where most values lie. On the other hand, in nominal scale, as data is not arranged in any order median cannot be applied. A median cannot be used in further mathematical calculations and therefore it cannot be used in statistical analysis. For nominal and ordinal scale mode can also be calculated and for nominal scale mode is the only value that can be calculated.

- Manikandan, S (2011). “Measures of central tendency: Median and mode”.
*Journal of Pharmacology and Pharmacotherapeutics*.**2**(3): 214, 215. doi:10.4103/0976-500X.83300. PMC 3157145. PMID 21897729. - Chrisman, Nicholas R. (1998). “Rethinking Levels of Measurement for Cartography”.
*Cartography and Geographic Information Science*.**25**(4): 231–242. doi:10.1559/152304098782383043. ISSN 1523-0406. Retrieved 14 August 2015. – via Taylor & Francis - Boone N. Harry (2012).
*Analyzing Likert Data. Journal of Extension*. April 2012 Volume 50 Number 2 Article Number 2TOT2. West Virginia University. - Gail M. Sullivan, MD, MPH and Anthony R. Artino, Jr, PhD.
J Grad Med Educ. 2013 Dec; 5(4): 541–542. doi: 10.4300/JGME-5-4-18.*Analyzing and Interpreting Data From Likert-Type Scales. Journal of Graduate Medical Education.*

The post Ordinal Scale in Research Methodology appeared first on Reading Craze.

]]>