There are valid instruments that are in use presently, for example the Functional Assessment of Cancer Therapy consists of a core instrument (FACT-G) and its various sub-scales such as the FACT-C for colorectal cancer [ 6].
While over the past years, no norms, standards, and scientific criteria for the concept of familiarity and its core instrument of reference controls were developed, it is still at the discretion of applicants and authorities if and how to use the respective test results.
The development of the HAEM-A-QOL included focus groups with patients, physicians and nurses, the draft version of the questionnaire was first compared with the items of the HAEMO-QoL questionnaire to have a core instrument available both for children and adults, before being comprehension tested and psychometrically validated 19.
The factorial model of the patient-reported QoLISSY core instrument, which comprises the physical, social and emotional domain and a total score of HrQoL, had an acceptable fit, with Χ2 (206, n = 263) = 615.35, p <.05, Χ2/df = 2.99, CFI =.88 and RMSEA =.087.
But that was merely a news-media approximation of the "reputational survey," the core instrument in the U.S. News rankings and one of the more controversial practices in the ranking business.
Apart from the gradiometer as the core instrument, the first ESA Earth Explorer Core Mission GOCE (Gravity field and steady-state Ocean Circulation Explorer) will carry a 12-channel GPS receiver dedicated for precise orbit determination (POD) of the satellite.
These authors anticipated that the instruments would evolve with time and that the core instrument would be sufficiently brief to allow investigators to add other measures to the battery dependent on their research interest.
This is currently the case for SAFARI, a core instrument developed by a European-based consortium, and BLISS proposed by CALTECH/JPL in the US.
As long as the adaptation process from original to new instrument is carefully and methodically performed, with sensitivity to the original instrument's purpose and theoretical foundation, the core instrument remains the same.
These instruments will be used to answer RQ 3 and 4. The core instrument of the study is a standardised diagnostic interview used to collect data on the prevalence and incidence of mental disorders in the elderly (RQ 3 and 4).
