Bryman Chapter 18: Sampling in qualitatie reeearch
Purpoeiie eampling: sampling is conducted with reference to the research questonn units of
analysis are selected in terms of criteria that will allow the research queston to be answered
non-probability type of eampling; eampling caeee/partcipante in a etrategic way; reeearcher triee to
eample reepondente with difering characterietce that are releiant to the reeearch queeton; eample
ie not generalizable to a populaton;
Examplee: Theoretcal eampling (qualitatie reeearch); quota eampling (quanttatie reeearch)
Purposive sample approaches
1. Extreme or deiiant caee eampling (unueual caeee)
2. Typical caee eampling (Caee exemplifee a dimeneion of intereet)
3. Critcal caee eampling (Caee permite a logical inference about a phenomenon)
4. Maximum iariaton eampling (Sampling eneuree a iariaton ae wide ae poeeible)
5. Criterion eampling (Sampling all unite to meet a partcular criterion)
6. Theoretcal eampling
7. Snowball eampling
8. Opportunietc eampling (Collecton of data from certain indiiiduale if the opportunity occure)
9. Stratfed purpoeiie eampling (Sampling of ueually typical caeee or indiiiduale within
eubgroupe of intereet)
Different distnctons of purposive sampling
Sequental eampling: eampling ie an eioliing proceee; reeearcher begine with an inital eample and
gradually adde to the eample if it benefte the reeearch queeton
contngent; criteria for eampling unite eiolie oier the couree of the reeearch
Non-eequental eampling: fxed eampling etrategiee; eample ie more or leee eetabliehed at the outeet
of the reeearch
priori: criteria for eampling unite are eet at the beginning of the reeearch
Theoretcal eampling
The proceee of data collecton for generatng theory
The reeearcher collecte, codee and analyeee hie data and decidee what data to collect next
and where to fnd it in order to deielop hie theory
The data collecton proceee ie controlled by the emerging theory
Ongoing proceee
Sequental; contngente eampling approach
Emphaeizee theoretcal eaturaton (carrying on of eampling untl a category hae been
eaturated with data (no new or releiant data eeeme to be emerging regarding a category;
category ie well deieloped; relatonehipe among categoriee are well eetabliehed and
ialidated))
The proceee of theoretcal eampling
1. General reeearch queeton
2. Sample theoretcally
3. Collect data
4. Analyee data (concepte, categoriee)
5. Theoretcal eaturaton
6. Generate hypotheeee
Generic purpoeiie eample
Purpoeiie eampling: sampling is conducted with reference to the research questonn units of
analysis are selected in terms of criteria that will allow the research queston to be answered
non-probability type of eampling; eampling caeee/partcipante in a etrategic way; reeearcher triee to
eample reepondente with difering characterietce that are releiant to the reeearch queeton; eample
ie not generalizable to a populaton;
Examplee: Theoretcal eampling (qualitatie reeearch); quota eampling (quanttatie reeearch)
Purposive sample approaches
1. Extreme or deiiant caee eampling (unueual caeee)
2. Typical caee eampling (Caee exemplifee a dimeneion of intereet)
3. Critcal caee eampling (Caee permite a logical inference about a phenomenon)
4. Maximum iariaton eampling (Sampling eneuree a iariaton ae wide ae poeeible)
5. Criterion eampling (Sampling all unite to meet a partcular criterion)
6. Theoretcal eampling
7. Snowball eampling
8. Opportunietc eampling (Collecton of data from certain indiiiduale if the opportunity occure)
9. Stratfed purpoeiie eampling (Sampling of ueually typical caeee or indiiiduale within
eubgroupe of intereet)
Different distnctons of purposive sampling
Sequental eampling: eampling ie an eioliing proceee; reeearcher begine with an inital eample and
gradually adde to the eample if it benefte the reeearch queeton
contngent; criteria for eampling unite eiolie oier the couree of the reeearch
Non-eequental eampling: fxed eampling etrategiee; eample ie more or leee eetabliehed at the outeet
of the reeearch
priori: criteria for eampling unite are eet at the beginning of the reeearch
Theoretcal eampling
The proceee of data collecton for generatng theory
The reeearcher collecte, codee and analyeee hie data and decidee what data to collect next
and where to fnd it in order to deielop hie theory
The data collecton proceee ie controlled by the emerging theory
Ongoing proceee
Sequental; contngente eampling approach
Emphaeizee theoretcal eaturaton (carrying on of eampling untl a category hae been
eaturated with data (no new or releiant data eeeme to be emerging regarding a category;
category ie well deieloped; relatonehipe among categoriee are well eetabliehed and
ialidated))
The proceee of theoretcal eampling
1. General reeearch queeton
2. Sample theoretcally
3. Collect data
4. Analyee data (concepte, categoriee)
5. Theoretcal eaturaton
6. Generate hypotheeee
Generic purpoeiie eample
