Quantitative Research Continued

Question 1

Describe various threats to EXTERNAL validity and how they can be minimized.
(MRS. GRRH)

Answer 1

• Multiple treatments
• Researcher-participant relationship
• Setting
• Generalizability
• Research bias
• Replication
• Hawthorne Effect

Question 2

Name various threats to reliability of a quantitative study.

Answer 2

Participant fatigue, motivation, learning, and ability to respond. Tester skill and number of testers (different testers vary in skill, ethusiasm, etc.)

Question 3

What is a sampling Frame?

Answer 3

People that you actually have access to

Question 4

Define sample?

Answer 4

people that are actually in your study

Question 5

How are inclusion and exclusion criteria determined?

Answer 5

Based on study purpose and research questions
• Based on literature review
• Based on assumptions and theoretical base

Question 6

What are the two major categories of sampling techniques?

Answer 6

Probability and non-probability

Question 7

How do probability and non-probability sampling differ?

Answer 7

• Non-probability
o Not random, not all members of population have equal chance to be a part of selection
o There are limitations in generalizability

• Probability
o Random; maximizes possibility that sample reflects the population; all members of population have equal chance of selection.
o Maximizes generalizability

Question 8

Name 4 types of nonprobability sampling.

Answer 8

Snowball, convenience, quota, purpose/judgement sample,

Question 9

Describe snowball sampling

Answer 9

o Used when access to participants who meet criteria is limited

Question 10

Describe convenience sampling

Answer 10

o Establish inclusion/exclusion criteria then take what you can get
o Easy, inexpensive, readily available
o Limited generalizability

Question 11

Describe quota sampling

Answer 11

o Divide population into 2 or more subgroups
o Draw representative samples from each subgroup according to occurrence in the population
o Enroll participants until quota is reached

Question 12

Describe purpose/judgement sample

Answer 12

o Hand selected based on specific predefined criteria

Question 13

Name 5 types of probability sampling.

Answer 13

• Simple random
• Stratified random
• Cluster
• Multi stage
• Systematic random

Question 14

Describe simple random sampling

Answer 14

o Participants in the population have equal chance of selection
o Increases likelihood of similarity of sample and population
o Define population->Compile exhaustive list of participants->Randomly sample

Question 15

Describe stratified random sampling

Answer 15

o Population is divided into 2 or more groups based on a characteristic
o Randomly sample each group
o Used to ensure that each subgroup is adequately represented

Question 16

Describe cluster sampling

Answer 16

o Divide population into smaller cluster and randomly sample
o Useful when population is spread out geographically
o Example: Randomly select hospitals in the region

Question 17

Describe multi-stage sampling

Answer 17

o Divide population into clusters and randomly sample; further subdivide population into second stage clusters and randomly sample
o Example: Randomly select region->randomly select hospitals-> randomly select patients

Question 18

Describe systematic random sampling

Answer 18

o Randomly order participants, then select every nth one-depending on sample size; more efficient than simple random