Ideally this variance should be based on results from empirical data, for example, former systematic reviews, former randomised clinical trials, or large observational studies.
Efforts in a number of countries to collect standardised data on case mix and outcomes for paediatric cardiac surgery (including our own national audit in the UK) have led to a shift from the use of consensus-based risk stratification tools (eg, RACHS-1 1 and ARISTOTLE 2) to risk estimates based on empirical data, for example, the STS-EACTS score.
As a consequence, mate attraction is expected to be under strong negative selection in asexual species where it is superfluous, a prediction largely supported by empirical data (for example, Lehmann et al., 2011; reviewed by van der Kooi and Schwander, 2014).
The selections elucidate the major themes and also present students with a wealth of empirical data and examples--drawn from both developing regions and industrial countries--that demonstrate similarities and differences in practice and encourage further research.
In addition, many formal models use generic numerical examples rather than empirical data for illustrative examples.
Social scientists collect, reflect on and derive themes, meanings and theories from empirical data from, for example, interviews and observation.
Few studies have differentiated between new acquisitions and old colonisations of nosocomial pathogens using empirical data, with a rare example being Kho et al. [ 14].
Our example with empirical data showed similar overall discriminative ability of the standard model and the random intercept model, if the cluster specific effects (estimated by a random intercept) were not used in the risk calculation.
In the simulation example, the empirical accuracy was the correlation between the TBV and EBV (or GEBV), whereas in the Merino data example, the empirical accuracy was the correlation between the ASBV and EBV (or GEBV).
Students have spent their summers in India, for example, gathering empirical data on the country's pharmaceutical networks.
