The phrase "principal research question" is correct and usable in written English.
For example, you could use it in the following sentence: "Presented in this study is the principal research question of whether or not the new policy will reduce emissions."
A principal research question to deal with is how to design Take-Over-Requests (TOR) with respect to the human machine interface (HMI) and reaction times to comply with a TOR.
This is partly due to the fact that such tools necessarily tend to reflect the quality of reporting of data relevant to a clear principal research question.
The principal research question in the Second Study of Infectious Intestinal Disease in the Community (IID2 Study) is:- Has the incidence of IID in England in the community declined since the mid 1990s?
A separate analysis was conducted for each of the five outcome variables, and the main effect of trial arm (telehealth v usual care) was estimated to answer the principal research question.
Each member was asked to identify texts within the document that they considered in any way to be linked to the principal research question of good practice in training professionals in mental health promotion.
The principal research question of the SWAP trial is: What is the effect of the addition of a vocational advice service to best current care compared to best current care alone, for adults with musculoskeletal conditions in primary care absent from or struggling to remain in work?
Specifically, the principal research questions include the following: 1. Are there any differences in utilization of learning styles in mathematics among students between the four countries?
Presentation of results should reflect the analytical strategy with an emphasis on the principal research questions.
The intention to treat analysis to address the principal research questions will be conducted using the one-year follow-up data.
The second consideration is the analytical strategy, which should follow CONSORT guidelines.[ 9] In particular, the primary analyses should address the principal research questions.
40 44 We conducted two prospective studies of high-risk young women engaged in transactional sex in Phnom Penh, the principal research questions focused on estimating HIV and STI prevalence and incidence and associated risk factors.
