Reliability and validity of research tools

Precision and accuracy Validity [3] of an assessment is the degree to which it measures what it is supposed to measure. This is not the same as reliabilitywhich is the extent to which a measurement gives results that are very consistent. Within validity, the measurement does not always have to be similar, as it does in reliability. However, just because a measure is reliable, it is not necessarily valid eg.

Reliability and validity of research tools

Depression Assessment Tools Screening for Depression Sharp and Lipsky reviewed several depression screening measures for their appropriateness of use in primary care settings.

Matthew Lombard

The prevalence of depression in adults older than 65 years of age ranges from 7 to 36 percent in medical outpatients and increases to 40 percent in hospitalized elderly patients. Up to 50 percent of patients with Alzheimer's disease or Parkinson's disease develop a depressive disorder, and their caretakers--no matter what their age--are also at an increased risk.

Signs of depression that are more common in the elderly than in other populations include diminished self-care, irritability, and psychomotor retardation.

Early diagnosis and treatment of depression in the elderly improve quality of life and functional status, and may help prevent premature death. When using screening instruments with elderly patients, it is important to consider their level of cognitive impairment along with visual deficits.

The validity of certain depression screening instruments is significantly decreased in patients with a Mini-Mental State Examination score of 15 or less. A one-item screening question, "Do you often feel sad or depressed? In cognitively intact patients older than 65 years, the GDS or one-item screen are currently the preferred instrument because the psychometric data on the BDI and CES-D are mixed in this population.

Sharp and Lipsky, Self-Administered Tools These instruments involve the subject answering a questionnaire that is then scored.

Steer, and Gregory K. It takes minutes to administer, longer for patients with severe depression or obsessional disorders Constructs Measured: The BDI-II is a item self-report instrument intended to assess the existence and severity of symptoms of depression.

This new revised edition replaces the BDI and the BDI-1A, and includes items intending to index symptoms of severe depression, which would require hospitalization. The BDI has been used for 35 years to identify and assess depressive symptoms, and has been reported to be highly reliable regardless of the population.

One of the main objectives of this new version of the BDI was to have it conform more closely to the diagnostic criteria for depression, and items were added, eliminated and reworded to specifically assess the symptoms of depression listed in the DSM-IV and thus increase the content validity of the measure.

Assessment in Minorities and Elderly: LS Radloff Administration: The CES-D consists of 20 items and takes 5 to 10 minutes to complete. The CES-D was developed for use in studies of the epidemiology of depressive symptomatology in the general population.

The CES-D was evaluated for subsets of the original population including persons older than 64 and Blacks. The GDS consists of 30 items and takes 10 to 15 minutes to complete.

The short version of the GDS consists of 15 items and takes 5 to 10 minutes to complete. The items included in the GDS were selected from previously published scales.

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The GDS is internally consistent and externally valid in comparison with clinically diagnosed depression. The GDS is specifically written for rating depression in the elderly. It was tested in a population above age The reliability and validity of a measure is not established by any single study but by the pattern of results across multiple studies.

The assessment of reliability and validity is . Reliability is a necessary ingredient for determining the overall validity of a scientific experiment and enhancing the strength of the results. Debate between social and pure scientists, concerning reliability, is robust and ongoing.

Reliability and Validity. In order for research data to be of value and of use, they must be both reliable and valid..

A Primer on the Validity of Assessment Instruments

Reliability. The validity of the design of experimental research studies is a fundamental part of the scientific method, and a provide a starting point for a discussion about a wide range of reliability and validity topics in their analysis of a wrongful murder conviction. See also. Concurrent validity; Content validity; Construct validity;.

Screening for Depression. Sharp and Lipsky () reviewed several depression screening measures for their appropriateness of use in primary care settings. Assessment methods and tests should have validity and reliability data and research to back up their claims that the test is a sound measure..


Reliability is a very important concept and works in tandem with Validity. A guiding principle for psychology is that a test can be reliable but not valid for a particular purpose, however, a test cannot be valid if it is unreliable.

Reliability and validity of research tools
Validity and reliability | Institute for Work & Health