Which of the following are characteristics of quantitative research? (Select all that apply)

A. The protocol should clearly indicate how design aspects will happen: A research protocol outlines the study design, procedures, instruments, and timing of data collection to ensure methodological consistency. Clear specification of design elements enhances internal validity and reproducibility. It also allows ethical review boards to evaluate participant protection and scientific rigor before implementation.

B. Having a detailed procedure for collecting the data is important: Standardized data collection procedures reduce variability and measurement error. Detailed instructions ensure that all researchers collect data in a consistent manner, improving reliability and minimizing bias. This is especially critical in multicenter or large-scale studies.

C. Getting the data collection correct first time is important: Errors during initial data collection can compromise validity and may not be correctable later, particularly if participants are lost to follow-up. Inaccurate or incomplete data weaken statistical power and threaten study credibility. Careful execution from the outset protects the integrity of the research findings.

D. Before collecting the data, a plan should be established to explain exactly how the data will be obtained: Preplanning ensures clarity regarding instruments, timing, setting, and data management procedures. A structured plan reduces ambiguity, prevents protocol deviations, and supports consistency across participants.

A. Mixed research method: Mixed methods research combines both qualitative and quantitative approaches within the same study design. A one-to-one interview by itself does not constitute mixed methods unless it is paired with quantitative tools such as surveys or statistical analysis. Therefore, an individual in-depth interview alone does not represent a mixed research design.

B. Qualitative research method: One-to-one interviews are a hallmark of qualitative research because they explore participant perspectives, lived experiences, meanings, and social contexts. This method allows for open-ended questioning, probing, and rich narrative data collection. The goal is depth of understanding rather than numerical measurement or statistical inference.

C. Quantitative research method: Quantitative research focuses on measurable variables, numerical data, and statistical analysis. Structured questionnaires with fixed responses may be quantitative, but in-depth one-to-one interviews aim to gather descriptive, non-numerical data. The emphasis on detailed experiences aligns with qualitative methodology rather than quantitative design.

D. All of the above: Because one-to-one interviews are fundamentally qualitative in nature unless integrated into a broader mixed-methods framework, they do not simultaneously represent all research approaches. The method itself is most directly aligned with qualitative inquiry.