Research Methods 3-= Sampling Flashcards
Reseaech methods 3n4 sampling
Population
Group of people who r focus of researchers interests
Reseaech methods 3n4 sampling
Sample is
Group of ppl who take part in study. Sample drawn fro population.shouod be representative.
Reseaech methods 3n4 sampling
Bias is
When group is over o under represented.
Reseaech methods 3n4 sampling
Strengths of random sampling
No researcher bias-equal chance of being selected. Researcher cannot influence who takes part
Representative of target population-all member have equal chance of being selected however its not guaranteed it will be representative ,by small chance ppl with similar characters are selected but low possibility
Reseaech methods 3n4 sampling
Cons of random sampling not representative
Not representative -chance that those with similar characteristics r selected especially if sample size small if does happen decreases external val making difficult to generalise
Reseaech methods 3n4 sampling
Random sampling is
Every member of target pop has equal chance of being selected
Reseaech methods 3n4 sampling
Volunteer sampling is
Participants themselves have put forward that they wanna take part
Say what ad says n say where it’s put
Reseaech methods 3n4 sampling
Pros of volunteer sampling
Not time consuming
AD IS LINKED TO WHERE LOCATED likely to be quick n easy.to gather sample unless no volunteers save more time than stratified,systematic,random
Research methods 3n4
Random Sampling
Con time consuming
Time consuming takes ages to identify/write down/input all the names of pop
Research methods 3n4
Random sampling con
Sample may not be randomly chosen
It maybe that some chosen do not contest to take part so researcher must select more ppts doing more random sampling using remaining target pop -time consuming and may not represent -only represents ppts willing to engage
Research methods 3n4
Volunteer sampling cons
May not represent pup -volunteers maybe too similar,may not represent all differences of ppl in target pop decreases external val ,difficult to generalise -if stud requires specific sample choose volunteer cus ad explains specific pop ur looking for
Research methods 3n4
Systematic sampling is
Obtaining names of all n selects member to use in sample researcher obtains names of everyone in target then selects every nth person until they name enough ppts
Research methods 3n4
Systematic sampling is
Pro no researcher bias
No control over every nth number selected so not selected ppts they think will likely support their hypothesis increasing internal val
Research methods 3n4
Systematic sampling
Pro likely to represent target pop
Made up of all target so likely all different types ppl making pop represented in sample especially if it’s. Big sample ,external val increase however no guarantee a sample is representative
Research methods 3n4
Systematic sampling
Con may not represent
Maybe chance select those with similar characteristics ,if sample size too small it’s more likely. Reducing external val if happens
Research methods 3n4
Systematic sampling
Time consuming
Especially if target pop is large
Identifying, writing inputing all names -time
Research methods 3n4
Systematic sampling
May not select all willing ppts
Have to do again with the remaining willing member of talent pop ,may not represent as u only include those willing to engage in study
Research methods 3n4
Stratified sample
Is
Sample mirroring target pop so that proportion of each subgroup are same in target pop n sample
Research methods 3n4
Stratified sample process
Identify subgroup in pop
Calc number of each subgroup required based on proportion of pop
Write name of every member on piece of paper n put them in diff containers according to subgroup they belong to
Draw out required number of names for each subgroup
Research methods 3n4
Stratified sample
Pro no researcher bias
Random selection of subgroup member
So not selected ppts they think will likely support hypothesis
Research methods 3n4
Stratified sample pro target is to mirror all charateristics
Likely Represents all diff Types increasing external val
But impossible to account for all the many ways ppl differ so never full represnetative
Research methods 3n4
Stratified sample
Cons
Time consuming especially if big pop with lots of diversity
To identify all subgroups
Research methods 3n4
Opportunity sample is
Taken using convenient members of target pop who r willing n available eg researcher asks students leaving library to take part in study (say where approached n who target pop is)
Research methods 3n4
Opportunity sample
Pro not time consuming
Lots might agree when walking past -accessible ,convenient
