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Research Process Guide

Step 8: Collecting Data

Entirely dependent on your research questions and methodology, the data collected will be different depending on your research purpose and goals. As a brief review, here are the methods, instruments, data analysis for the different methodological approaches:

Methods Instrument Kinds of Data Analysis Framework
Quantitative (deductive) Pre-determined, instrument-based questions, experimental design, or survey structured interviews, surveys, performance data, observational data, census data Statistical analysis and interpretation Postpositivist
Mixed Methods Both predetermined and emerging methods-sequential, convergent, transformative Both open and close ended questions, multiple forms of both numerical and non-numerical data Statistical analysis and text analysis Pragmatic
Qualitative (inductive) Emerging methods, Grounded Theory., Ethnographic, Narrative, Phenomenological, Case Study Interview data, observational data, document data, audiovisual data Text and image analysis Transformative Social Constructivists, Postmodernist,
Critical Theory


The types of data collected using quantitative methods (Creswell & Creswell, 2018; Bouma et al., 2012) include:

  1. Survey or questionnaires, polls
  2. Structured interviews
  3. Experiments
  4. Controlled observational data
  5. Probability sampling

Sampling in Quantitative Methods

In quantitative research, getting a sample size that is a cross section of the population looking to be studied is the goal. It is called probability sampling. It is important that there can be generalizability, and randomization within the sample population. There are many different types of probability sampling. Once you have determined the hypothesis to be tested and the measurements and variables you will examine in your study, you can determine which method of probability sampling is best (Creswell & Creswell, 2018).

Tip: when constructing a survey, questionnaire, interview protocol, try to match each question with your research questions, so that you are sure to get the data you are looking for to answer your research questions.

The types of data collected using qualitative methods (Miles et al., 2018; Creswell & Poth, 2018) include:

  1. Semi-structured, unstructured interviews
  2. Focus groups
  3. Observational data
  4. Documents
  5. Field notes
  6. Archives
  7. Pictures/video

Sampling in Qualitative Methods

There are several different types of non-probability sampling in qualitative research. Most of the time, the sampling technique depends on the kind of approach you are taking. However, four of the most common sampling methods are (Stratton, 2021; Creswell & Creswell, 2018):

  1. Purposeful sampling - participants are directly selected by the researcher from the population being studied.
  2. Snowball sampling - participants are often referred to the researcher by other participants.
  3. Convenience sampling - the researcher announces the study and participants self-select if they wish to participate.
  4. Quota sampling - is layered onto a systematic population segmentation process, often done with “street” interviews in which people are profiled for characteristics that may fit the study objectives for participants.


Tip: Regardless of your methodology, it is important to justify where you are collecting your data, how, and from whom. Often, these are called descriptive statistics, which serve to give context to your study. You are required to be sure that your participants are aware of the purpose of the study, know that they can back out at any time, understand the confidentiality of your study, and are aware of any risks to themselves and others (See Research on Human Subjects - IRB section).


Bouma, G. D., Ling, R., & Wilkinson, L. (2012). The research process (2nd Canadian ed.). Oxford University Press.

Creswell, J. W., & Creswell, J. D. (2018). Research design: Qualitative, quantitative, and mixed methods approaches. Sage.

Creswell, J. W., & Poth, C. N. (2018). Qualitative inquiry and research design: Choosing among five approaches (5th ed.). Sage.

Miles, M. B., Huberman, A. M., & Saldaña, J. (2018). Qualitative data analysis: A methods sourcebook. Sage.

Stratton, S. (2021). Population research: Convenience sampling strategies. Prehospital and Disaster Medicine, 36(4), 373-374. doi:10.1017/S1049023X21000649