Qualitative Sampling Strategies

Qualitative Research

seeks to answer a question / explore a phenomena

collects evidence

produces findings that were not determined in advance

generalizable & applicable beyond immediate study

from perspective of local population of involvement

culturally specific

values

opinions

behaviours

social contexts

Methods (semi-structured)

Participant Observation

In-Depth Interviews

Focus Groups

collects data on naturally occurring behaviours in their usual context / setting

collects data on cultural norms of a group

collects data on an individual's personal history, perspective, experience

Forms

field notes

audio / video recordings

transcripts

Describes & Explains

variation

relationships

individual experiences

group norms

open-ended

textual & iterative

Sample: subset of population selected for any given study

Sufficiency

Explanation

Most Common Non-Probability Sampling Methods

research objectives and characteristics of study population (such as size and diversity) determine which and how many people to select

2) Quota

3) Snowball

1) Purposive

definition: groups participants according to preselected criteria relevant to a particular research question

sample size: depend on resources and time available, as well as study's objectives. often determined on basis of theoretical saturation

definition: sometimes considered a type of purposive sampling; decide while designing the study how many people with which characteristics to include as participants - age, gender, class, marital status, profession, etc.

sample size: go into community and using recruitment strategies appropriate to the location, culture, and study population, find people who fit the criteria until quota is met

more specific than purposive sampling with respect to sizes and proportions of subsamples

definition: considered a type of purposive sampling; researchers rely on participant referrals and/or social networks to recruit members for study

sample size: find and recruit "hidden populations" and becomes larger along the way

Too Small

doesn't support redundancy

doesn't support theoretical saturation

Too Large

doesn't permit in-depth analysis

matter of judgement and experience

evaluate quality of information collected

understand the uses to which the information will be put against, the method employed, and the product intended

Principle of Saturation

sample size large enough to sufficiently describe the phenomenon of interest and address the research question

repetitive data

adding more participants to the study doesn't result in obtaining additional perspectives and/or information