Levels Of Measurement And Concepts Of Validity – Coursework Example
Levels of Measurement and Concepts of Validity Measurement refers to the act of determining the amount, length, or size of a physical element. Measurements are often taken to facilitate various activities such as design and determination of physical properties of objects. There are various methods, tools and levels of measurements that can be employed while undertaking the activities. This paper talks about measurement levels, as well as about the validity of measurements and design.
There are four levels of measurement which include nominal, ordinal, interval, and ratio scales (Garger). Nominal scales are the most basic and categorize entities that share a common trait together. For example, results of tossing a coin can be grouped into heads and tails. Ordinal scales rank data, interval scales show differences between objects, while the ratio scale provides an absolute measurement. Data measured using ratio, ordinal, and interval scales can be transformed backward to the lower level since they have extra properties that can be dropped (Research Methods in Psychology). To convert from ratio to ordinal, convert the data to ranks. For example, time in seconds can be converted from its ratio form to ordinal form by ranking the number of seconds in either ascending or descending order. On the other hand, data measured using nominal scales cannot be converted because one cannot add properties that do not exist to a data set. For example, while tossing a coin, the coin can only land on one side; either head or tail. No information can be added or removed; hence this type of data cannot be transformed.
Validity for design seeks to authenticate procedures and processes that are used while conducting researches. It ensures that all activities that researchers carry out are relevant. According to Tariq, validity for design checks for design validity in a number of areas; face validity, content, contract, internal, statistical conclusion, external, and criterion related validity. Each of these ensures that the overall validity of the design is up to standard.
On the other hand, validity for measurement is the level to which tools used in measurement measure the theoretical concepts they are meant to measure. It not only seeks to ensure that only the required measurements are taken, but also that the measurements are taken as required; with the right tools, methods, and at the correct time (Sapsford).
Garger, John. 4 Levels of Measurement in Social Science Research. John Garger, 4 July 2010. Web. 24 Sept. 2012.
Research Methods in Psychology. Levels of Measurement. researchmethodsinpsychology.com, 23 April 2007. Web. 24 Sept. 2012.
Sapsford, Roger. Validity of Measurement. Sage, 2006. Web. 24 Sept. 2012
Tariq. Validity in Research Design. Active Campaign, 2 Jan 2009. Web. 24 Sept. 2012.