Perhaps the most difficult aspect of aggregating data from multiple sources, aside from the methodological variation in its creation, is the variation in degree of description and terms used to describe the data.
While the proliferation of different TTO specifications may be seen as a valuable and integral part of the scientific endeavor to achieve optimal valuation methods, methodological variation in TTO studies is problematic from a policy point of view.
Despite the considerable methodological variation in resilience studies, the fact that a common set of child, family, and social resources have been consistently recognised in resilience suggests that these resources are all implicated in the same underlying phenomenon, and support the validity of resilience as a construct [ 18, 23, 80].
Differences between studies are likely due to methodological variations in regards to dose, route of administration and treatment duration.
These differences may be explained by methodological variations in the in vitro models used, suggesting that HAM was more affected by the experimental conditions.
However, comparisons across the seven studies selected in this review were difficult because of methodological variations in definition of attrition, sample composition, and the factors considered potential predictors.
Methodological variations in generation of the underlying cDNA sequences, e. g. 5'-, 3'- or full length cDNA enrichment, may have led to additional bias in the datasets.
This difference could be due to methodological variations; in the case of the Jimma study, the result was confirmed based on the test result of HIV and STIs, where as in the present case, it was merely self report.
A source of variability in results not only comes from methodological variations in tissue processing (time to fixation, duration of fixation, denaturation, heating, antigen retrieval, the staining procedure) and grading scores but also from the antibody used.
It is likely that the differences are partly due to the methodological variations in assessing strength, but it also possible that testosterone has different effects on the various muscle groups.
Second, due to methodological variations in data acquisition (e.g., continuous fMRI and EMG recordings vs. ordinal expectancy ratings) and in data processing (e.g., the possibility of separating early vs. late acquisition in the behavioral but not in the neural data) across the different measures of fear learning, we inevitably had to average and analyze over different numbers of trials.
