Through the requirements of funding, the direction of new inquiry is itself hostage to results from existing studies; one must first peruse vast volumes of existing research and extract from them enough evidence to prove the viability and the usefulness of the study one wants to undertake.
Just as our biology research begins with a theoretical perspective and builds on existing studies, we must conduct our education research with the same standards.
However, the lack of a review on trust in VANETs to sum up the best available research on specific questions is sensible, which must be done by synthesizing the results of existing studies.
Existing studies have yielded mixed results.
Existing studies have significant limitations.
Existing studies show various consequences.
Although most of the findings were significant, certain limitations existing in the study must be recognized.
Once participants are identified and consent is confirmed, existing participant data records from relevant primary studies must be retrieved for reuse.
The large number of patients required, the length of time the study must run, existing accepted follow-up practices in different countries, and the difficulty of managing patients on different follow-up strategies within the same centre all pose problems for the design of a randomized trial.
Moreover, in nearly all studies, only the epistatic effects of genes with previously proven and significant main effects were studied; consequently, the number of existing interactions must have been underestimated[ 31].
