Scientific expert witness testimony has the potential for affecting most court decisions in civil and criminal proceedings. Since experts were first utilized in English courts beginning in the 14th century, most contemporary courts struggle with seeking a balance between plaintiff and defense counsel allowing each party its day in court while taking into account the work which other courts have done previously in determining the admissibility of expert witness testimony. When these challenges present themselves in the courtroom, often other courts have approached these identical issues, many in proceedings involving the same expert(s). Confronted with these challenges, trial judges want to understand whether a new Daubert hearing must be held, deal with the issue from a clean slate approach or whether they must reinvent the proverbial wheel. Given these dilemmas, this exposition is based within a heuristic approach that will focus on the consideration of comprehensive data inclusion from an evidentiary foundation as it applies to expert witness testimony admissibility in neurolitigation. While the evidential force of FRE 702 specifically applies to admissibility of scientific evidence, it makes sense that along with scientific, objective data, inclusion of non-medical and other data in forming and admitting expert opinions, have mutual bearing upon the validity of opinions arrived at through neuropsychological assessment. It is these multi-data that should be factored into account when applying the Federal Rule of Evidence 702 scientific admissibility standard. Data from other relevant sources is just as vital as data obtained from objective measures, and co-exists with objective data. Without the integration of this information into resulting diagnostic data and opinions, one's methodology is open to scrutiny and can willfully be characterized as engaging in "junk science". Specific, pragmatic issues are discussed in order to avoid the plausible "junk science" question and to ultimately arrive at a factual and evidenced-based admissibility and reliability determination for the courts. Given the current standard, this article proposes an inclusionary method in neurolitigation as it would necessarily apply to Federal Rule of Evidence 702 which would extend to the integration of data outside medical and scientific information bases to establish accurate opinions for the trier of fact. In so doing, neuropsychological test data, non-medical data and expert testimony would be strengthened through inter-data consistency.