Module 3

Question 1

Sample

Answer 1

• small group that represents your target population (everything/one that you want to understand)
• a group of participants, treatments, or situations selected from a defined population

Question 2

Sample Population

Answer 2

• Mean = μ
• Standard deviation = σ
• you cannot exactly measure either of these as they are hypothetical

Question 3

Sample parameters

Answer 3

• Mean (x̄),
• Standard deviation= (s)

Question 4

how to find your sample

Answer 4

• defining the population of concern
• specifying a sampling procedure
• random, stratified, systematic, clustered, convenience
• specifying sampling method

Question 5

Sampling Bias

Answer 5

• when the individuals selected for a sample over or under represent certain population attributes that are related to the phenomenon under study
• can happen on purpose or by accident
• to prevent this there should be randomization

Question 6

Target Population vs Accessible population

Answer 6

• target population: overall group in which the researchers intend to generalize findings about
• Accessible population: portion of target population that has a chance of being selected to study

Question 7

Inclusion criteria

Answer 7

• primary traits of the target and accessible populations that will qualify someone as the subjects
• it is important to consider if these factors are important to the question

Question 8

Exclusion criteria

Answer 8

• factors that would exclude someone from being a subject
• these factors would be considered to be confounding to the results of the study

Question 9

Probability samples

Answer 9

• random selection
• everyone has an equal chance (or probability of being chosen)

Question 10

Non probability samples

Answer 10

• made through non random methods
• done when you need something very specific from your sample pool
• sampling techniques:
  1. convenience sampling: chosen on basis of availability (volunteers, recommendations)
  2. Snowball: participants identify and recommend other potential participants who are deemed fitting to the research purpose
  3. Purposive: sampling with a defined purpose
  4. Expert Sampling

Question 11

Purposive Sampling extended

Answer 11

• Maximum variation: heterogeneous
• homogeneous purposive sampling: sample one type
• extreme case sampling
• critical case sampling

Question 12

Sampling Error

Answer 12

the difference between the sample averages (statistics) and population averages (parameters)

Question 13

Probability sampling techniques

Answer 13

• randomized sample
• systematic sample: random start and every nth person
• stratified random sample: divide population into “strata” based on shared features then randomly select an amount from each
• cluster sampling: divide population into “clusters” that include all of the original diversity then randomly select the cluster used