Construction and Application of a Statistical Test for Coefficient of Variation on Normal Distributions

Abstract

In this study a novel statistical test is derived for the Coefficient of Variation (CV) under normal distributions. This is a newly derived test with value to engineering sciences in aspects of production of accurate items. The CV can measure the precision of a measuring instrument, among other applications. In order to determine instrument reliability, start by generating measures using the instrument. The CV is then calculated to determine if the measures generated by the instrument are concentrated around a central point. In use of normal distribution presumption, or approximation, applicable properties of the normal distributions lead to involvement of the chi-square and t-distributions. A CV test is then constructed, and two illustrative examples conclude the discussion.

Investigating and determining the crucial construction site supervisory competencies influencing the effectiveness of building construction project activities

“…The coefficient of variation (CV) values for each competency were computed in order to assess the validity and reliability of the results. The ratio of standard deviation to RII is known as the CV value (Solly and Gezani, 2017), whereas the dependability of the outcome is guaranteed by a CV value of less than 0.3 for each element/factor, according to Statistics Canada (2020).RII ≥ 0.9: Extremely High (EH)0.9 > RII ≥ 0.8: High (H)0.8 > RII ≥ 0.7: High – Moderate (HM)0.7 > RII ≥ 0.6: Moderate (M)0.6 > RII ≥ 0.5: Moderate – Low (ML)0.5 > RII ≥ 0.3: Low (L)0.3 > RII: Extremely Low (EL)…”

“…The coefficient of variation (CV) values for each competency were computed in order to assess the validity and reliability of the results. The ratio of standard deviation to RII is known as the CV value (Solly and Gezani, 2017), whereas the dependability of the outcome is guaranteed by a CV value of less than 0.3 for each element/factor, according to Statistics Canada (2020). RII ≥ 0.9: Extremely High (EH) 0.9 > RII ≥ 0.8: High (H) 0.8 > RII ≥ 0.7: High -Moderate (HM) 0.7 > RII ≥ 0.6: Moderate (M) The degree of agreement/relationship between the perspectives of DME and ATS levels of working categories on the competencies of construction site supervisors working in building construction projects was determined using Spearman's coefficient of rank correlation.…”

Organisational Elements Controlling the Labour Efficiency in Sri Lankan Road Construction Projects: Engineers’ Perspective

“…To test the validity and reliability of the findings, the coefficient of variation (CV) value for each component was also calculated. The CV value is determined using the standard deviation to the mean ratio of the data (Solly & Gezani, 2017). In this case, the lower CV value indicates that the responses are broadly in line with the mean values.…”