Text Ch.8

Question 1

Sampling links in with ______ validity

Answer 1

external

-the extent to which the findings drawn from the cases under examination may be used to make generalizations about phenomena outside the original study. Concerned with representativeness.

Question 2

Sampling Error is the difference between ______ _______ and ______ ______

Answer 2

Population Parameter and Sample Statistic

Question 3

Population Parameter Vs Sample Statistic

Answer 3

p. p= population characteristics, expressed in numeric terms when the responses of each member (or case) of the population are measured
s. s=

Question 4

Population Parameter Vs Sample Statistic

Answer 4

p. p= population characteristics, expressed in numeric terms when the responses of each member (or case) of the population are measured
s. s=a subset of the p.p

Question 5

3 factors in sample representativeness

Answer 5

1. Sample Frame
   -a list of the items or people forming a population from which a sample is taken.
   Consider:
   – Availability (or lack thereof)
   – Completeness
   – Accuracy
2. Sample Selection
   - probability sampling
   - non probability sampling
3. Sample size(if a probability sample)
   - as sample size goes up, error goes down

Question 6

Describe differences between probability and non probability sampling

Answer 6

Probability Sampling

• Based on probability theory
• Can estimate likelihood of representativeness
• Can estimate accuracy of sample statistics
• Appropriate for statistical analysis
  types: • Simple random • Systematic selection • Stratified • Cluster

Non-Probability Sampling
-NOT based on probability theory
-CanNOTestimate likelihood of representativeness
-CanNOTestimate accuracy of sample statistics
-NOT appropriate for statistical analysis (including percentages/frequencies)
Types: Accidental and Purposeful(most typical)

Question 7

Critiques of Sampling Frames: for probability sample and for Non-probability

Answer 7

Probability sample:

• What are possible gaps in the list?
• How could the sampling frame possibly introduce bias?

Non-probability sample:

• Convenience or purposive sample?
• Potential for ‘closed loops’?

.Does the goal of the research match the fact that it is non-probability or probability

Question 8

Qualitative Research and NonprobabilitySampling

Answer 8

Words/text, rather than numbers
Deep description
Seeks transferable, dependable findings
Does not argue representativeness

Question 9

Why use Non Probaility sampling

Answer 9

• Exploratory research
• Extremely small populations
• Unavailable/inadequate sampling frames
• High refusal populations
**Typically will stress that results may not be representative

Question 10

Critiquing Sampling Size

Answer 10

Probability sample: 
. Homogeneity of population 
. Number of variables 
. Sample selection
- Cluster sampling needs large sample sizes

Question 11

Data Saturation

Answer 11

Data saturation: point at which data collection no longer provides the researcher with new information

Question 12

Non Probability sampling: how to choose sampling size

Answer 12

Focus on quality of information obtained, rather than quantity of cases

Data saturation: point at which data collection no longer provides the researcher with new information

Question 13

population

Answer 13

in research the group that a researcher wishes to generalize about(ex: Canadian citizens); in content analysis, the texts most appropriate for answering the research questions

Question 14

sampling

Answer 14

the process of drawing a sample of cases from a larger population

Question 15

First step in a research project is to clearly identify the population being studied: 3 factors

Answer 15

1. Unit of analysis(indv,political parties,etc)
2. Geographic location
3. Reference perios

Question 16

representative sample

Answer 16

one that accurately represents the larger population from which it was taken

Question 17

sampling frame

Answer 17

is a list of all of the units in the target population

Question 18

sample selection method

2 main categories

Answer 18

1. probability

2. nON PROBABILITY

Question 19

Probability sampling

Answer 19

sampling based on probability theory allows us to estimate the likelihood that our sample provides a representative picture of the population
-random selection of a sample, each case in a population has an equal opportunity to be selected

Question 20

simple random sampling

Answer 20

the process by which every case in the population is listed and the sample is selected randomly from this list

Question 21

sampling distribution

Answer 21

theoretical distribution of a sample statistic (ex:the mean) for a given sample size

Question 22

confidence interval

Answer 22

the range of values within which the population parameter is likely to fall

Question 23

Sample Size

Answer 23

.when probability sampling techniques are used, sampling error is reduced as the sample size increases

Question 24

Homogeneity vs. Heterogeneity

Answer 24

refers to how similar a population is with respect to salient variables

refers to how dissimilar a population is

the more homogenous a population, the smaller the sample size needed

Question 25

3 factors that influence sample size needs

Answer 25

1. Homogeneity of a population 2. Desired Degree of accuracy 3. The complexity(number of variables) of the research

Question 26

systematic selection

Answer 26

a probability sampling technique in which the researcher calculates a selection interval and uses it to select cases from the sampling frame ex: is selection interval is 20, you select a number from 1-20 and start going 6, 26,46,66,86,106 - less random and less accurate than random sampling

Question 27

Stratified Sampling

Answer 27

.involves breaking the population into mutually exclusive subgroups, or strata, and then randomly sampling each group - each group is its own sampling frame - disproportionate stratified sampling is done when one subgroup of the population is way smaller but needs to be enhanced for sampling - Disproportionate is NOT representative of the population as a whole

Question 28

cluster sampling

Answer 28

is the process of dividing the population into a number of subgroups, known as clusters, and then randomly selecting clusters within which to randomly sample - saves time and money - not really representative either

Question 29

Types of probability sampling(3)

Answer 29

1. Systematic selection 2. stratifies sampling 3. Cluster Sampling

Question 30

Types of non-probability sampling(2)

Answer 30

1. accidental sampling - convenience or haphazard - the researcher gathers data from indv whome he or she accidently encounters or are convenient - self selection is just as biased 2. Purposive(judgemental) sampling - involves researcher selection of specific cases; the researcher uses his or her judgement to select cases that will provide the greatest amount of info - snowball sampling is often employed to study social networks - quota sampling when accidentall or purposive sampling is combined with stratification

Question 31

T OR F Non Probability sampling methods employ random selection of cases

Answer 31

FALSEEEEE -this means that we cannot identify margins of error or confidence intervals; thus it is more difficult to make generalizations and draw conclusions about the general population

Question 32

When are non-probability sampling appropriate?

Answer 32

when researchers are not seeking to make generalizations about a larger population, but are pursuing more in-depth descriptive information -also good for when probability sampling is not feasible: when sampling frames are inadequate, members of the population are likely to refuse to participate, or the population of study is extremely small

Question 33

Snowball sampling is what type of sampling? describe Snowball sampling

Answer 33

non probability, purposive sampling the researcher begins by identifying a few cases and , from these, gets referalls for other cases and continues to branch out

Question 34

spurious

Answer 34

the relationship between the independent and dependent variables that, while initially thought to be causal, is non-causal and is a function of the presence of athird variable, which causes the variation in both variables

Question 35

quota sampling is what type of sampling? describe quota sampling

Answer 35

non probability and probability, purposive and stratified sampling the researcher combines purposive or accidental sampling with stratification; the researcher identifies a number of target groups(strta) and then sets a quota number that must be met for each group