why is validity and reliability important

The blood pressure cuff measures the construct as it is defined in the literature. The type of validity assessed in this example is that of construct validity. Situation induced - 'white coat syndrome' Non-random error affects the validity of the instrument.Īre there any non-random sources of error possible in your assessment of Ms. If the blood pressure cuff always reads high, then it affects all of the measurements. The closer to 1, the more reliable the measurement. It is expressed as a correlation coefficient ( r) which will range from 0 to 1. This is called the coefficient of stability. The type of reliability assessed in this example is retest reliability. What might you do to attempt to help establish reliability of Ms. List 3 things that might have introduced random error into Ms. The more random error, the less reliable the instrument. View this table: Table 1 Types of validity The first category is content validity. Random error consists of chance factors that affect the measurement. It's important to consider validity and reliability of the data collection tools (instruments) when either conducting or critiquing research. There are two types of errors that may affect your measurement, random and nonrandom. In order to determine if your measurements are reliable and valid, you must look for sources of error. How do I determine if my measurements are reliable and valid? Using an opthalmoscope to measure blood pressure would not be a valid method. The use of a blood pressure cuff is considered to be valid because it is measuring blood pressure, not something else. Wilson, J.Validity is the extent to which the construct measures what it says it is measuring.Oliver, V, 2010, 301 Smart Answers to Tough Business Etiquette Questions, Skyhorse Publishing, New York USA.(2007) “Research methods in education” Routledge Cohen, L., Manion, L., Morrison, K, & Morrison, R.B.(2010) “The Practice of Social Research” Cengage Learning The e-book covers all stages of writing a dissertation starting from the selection of the research area to submitting the completed version of the work before the deadline. My e-book, The Ultimate Guide to Writing a Dissertation in Business Studies: a step by step assistance offers practical assistance to complete a dissertation with minimum or no stress. It is important to understand that although threats to research reliability and validity can never be totally eliminated, however researchers need to strive to minimize this threat as much as possible. Measures to ensure validity of a research include, but not limited to the following points:Ī) Appropriate time scale for the study has to be selected ī) Appropriate methodology has to be chosen, taking into account the characteristics of the study Ĭ) The most suitable sample method for the study has to be selected ĭ) The respondents must not be pressured in any ways to select specific choices among the answer sets. There are different forms of research validity and main ones are specified by Cohen et al (2007) as content validity, criterion-related validity, construct validity, internal validity, external validity, concurrent validity and face validity.

Validity of research can be explained as an extent at which requirements of scientific research method have been followed during the process of generating research findings. Oliver (2010) considers validity to be a compulsory requirement for all types of studies. According to Wilson (2010) reliability issues are most of the time closely associated with subjectivity and once a researcher adopts a subjective approach towards the study, then the level of reliability of the work is going to be compromised. Reliability is a concern every time a single observer is the source of data, because we have no certain guard against the impact of that observer’s subjectivity” (Babbie, 2010, p.158). In simple terms, if your research is associated with high levels of reliability, then other researchers need to be able to generate the same results, using the same research methods under similar conditions. It is noted that “reliability problems crop up in many forms. Reliability refers to the extent to which the same answers can be obtained using the same instruments more than one time.

Issues of research reliability and validity need to be addressed in methodology chapter in a concise manner.

Why is validity and reliability important