Quantitative Research: Sampling, Data, Collection, Measurement and Data Quality

Question 1

What is “N”?

Answer 1

N=population

-Entire aggregation of cases the researcher is interested

Question 2

What is “n”?

Answer 2

n=subset of population

Question 3

What are 2 key considerations of a representative sample?

Answer 3

1. Representativeness

2. Size

Question 4

Describe eligibility criteria

Answer 4

• Specifies population characteristics
• Cost
• Practical constraints
• People’s ability to participate
• Design considerations

Question 5

Probability Sampling

Answer 5

• Random sampling

- Estimates probability that an element will be included in sample

Question 6

Non-probability Sampling

Answer 6

• Elements selected by non-random methods

- No way to estimate the probability each element will be included in sample

Question 7

Convenience Sampling

Answer 7

Non-probability Sampling

-Using those who are the most available as participants

Question 8

Snowball Sampling

Answer 8

Non-probability Sampling

-Network or chain sampling by referral

Question 9

Consecutive Sampling

Answer 9

Non-probability Sampling

-Recruiting all from accessible population over specified time/size

Question 10

Purposive Sampling

Answer 10

Non-probability Sampling

-Researcher uses knowledge about population to select sample

Question 11

Simple Random Sampling

Answer 11

Probability Sampling

• Establishing a sampling frame
• Using random numbers to draw sample

Question 12

Stratified Random Sampling

Answer 12

Probability Sampling

• Subdivide population into homogenous subsets then randomly select sample
• Proportionate vs. disproportionate

Question 13

Multistage Cluster Sampling

Answer 13

Probability Sampling

-Selecting broad groups in stages then randomly selecting sample

Question 14

Systematic Sampling

Answer 14

Probability Sampling

• Selecting every kth case from a list
• Sampling interval
• Need a large population size to pick from

Question 15

Sampling Bias

Answer 15

• Systematic over-representation or under representation of population segment
• Based on population’s homogeneity

Question 16

Sampling Error

Answer 16

-Difference between population values and samples values

Question 17

What are the steps in sampling quantitative studies?

Answer 17

1. Identify the population
2. Specify eligibility criteria
3. Specify sampling plan: Methods of drawing sample and Power analysis
4. Recruit the sample

Question 18

Describe structured self-reports in data collection

Answer 18

1. Interview schedule: Face-to-face/telephone

2. Questionnaire the respondents complete themselves

Question 19

What types of questions can you ask in self-reports?

Answer 19

• Open ended questions: limit how many because ppl are less likely to respond
• Close ended questions:
  
  • Dichotomous
  • Multiple choice
  • Rank order
  • Forced choice
  • Rating
  • Visual Analog

Question 20

What are the differences between using questionnaires versus interviews?

Answer 20

Questionnaires:

1. Cost
2. Anonymity
3. Interview bias

Interviews

1. Response rate
2. Audience
3. Clarity
4. Depth of questioning
5. Missing info
6. Order of questions
7. Sample control
8. Supplementary data

Question 21

What’s response bias?

Answer 21

• Social desirability
• Extreme response
• Acquiescence response: agreeing because its easier

Question 22

What are structured observations?

Answer 22

-Documentation of specific behaviors, actions, events using formal instruments and protocols