Lecture 7

Question 1

Population

Answer 1

the entire set of persons, objects, or events that the researcher intends to study

Question 2

What is used instead of a population for studies

Answer 2

sample drawn from the target population

Question 3

What is external validity closely related to

Answer 3

inductive reasoning

Question 4

Inference

Answer 4

the process of generalizing from sample data to the population

Question 5

What can a representative sample confidently do

Answer 5

generalize to rest of population

Question 6

If the sample is biased (less representative) it has less ________ and may lead to what?

Answer 6

validity
incorrect conclusions

Question 7

What does selection of appropriate sampling method depend on?

Answer 7

the aims and resources of the researchers

Question 8

Good sampling methods are more expensive and difficult to implement, why are they worth it

Answer 8

gives credible data
accurate results
eliminate bias
make sure research is applicable to target audience

Question 9

6 sampling methods

Answer 9

incidental
random
quota
stratified random
area
systematic

Question 10

Incidental sampling

Answer 10

cheapest and easiest sampling method for conducting clinical studies

Question 11

Incidental sampling provides selection of what?

Answer 11

most accessible and available members of the target population

Question 12

Quota sampling

Answer 12

sometimes it is known in advance there are important subgroups within the population

Question 13

Quota sampling can be more __________ compared to incidental sampling

Answer 13

complex

Question 14

For quota sampling what do we need to know

Answer 14

which population groups are important to a question
the exact proportion of different groups in the population

Question 15

What is one of the best sampling methods

Answer 15

random sampling

Question 16

Random sampling is more ________

Answer 16

expensive

Question 17

In random sampling what do all members have?

Answer 17

an equal chance of selection

Question 18

Random sampling is more likely to be __________ than incidental sampling

Answer 18

representative

Question 19

Step 1 for drawing a random sample

Answer 19

constructing a list of all members of the population

Question 20

Step 2 for drawing a random sample

Answer 20

using a method like dice, coins, hat, or random number tables to select randomly from the list

Question 21

_______ can do random sampling efficiently, even with _______ populations

Answer 21

computers
large

Question 22

What may be introduced if you need to select replacements for some cases

Answer 22

bias may be introduced

Question 23

Advantages of random sampling: since sample and population sizes are known what can we estimate?

Answer 23

how representative the sample is

Question 24

Advantages of random sampling: more representative than what?

Answer 24

non-random samples

Question 25

Advantages of random sampling: ________ sample size necessary

Answer 25

smaller

Question 26

Disadvantages of random sampling: what do you need to list

Answer 26

every member of the population

Question 27

Disadvantage of random sampling: usually _______ and less ________ to use conveniently available groups

Answer 27

easier expensive

Question 28

Stratified random sampling

Answer 28

like quota sampling but with random sampling for each subgroup

Question 29

What are the subgroups of stratified random sampling called

Answer 29

the strata

Question 30

Advantages of stratified random sampling: important groups are what?

Answer 30

proportionately represented

Question 31

Advantages of stratified random sampling: what is known?

Answer 31

exact representativeness of the sample - important for stats

Question 32

Disadvantages of stratified random sampling: what list is required

Answer 32

a list of all members of the population, their characteristic(s) and the proportions of the important groups

Question 33

2 other disadvantages of stratified random sampling

Answer 33

cost gain in sample accuracy small relative to simple random sampling

Question 34

Area sampling

Answer 34

one sample on the basis of location of cases

Question 35

Area sampling is an effective and inexpensive method for what?

Answer 35

social surveys

Question 36

Area samples are not considered what?

Answer 36

truly random

Question 37

Systemic sampling

Answer 37

working through a list of the population and choosing every n-th case for inclusion in the sample

Question 38

What is the assumption of the list in systemic sampling?

Answer 38

it is arranged randomly

Question 39

If the list in systemic sampling is not random what could happen

Answer 39

risk of bias

Question 40

True or false: the sample size chosen is random

Answer 40

false

Question 41

What is an optimal sample size

Answer 41

one that is adequate to make correct generalization from the sample to the target population

Question 42

What should the sample size number be balanced with

Answer 42

costs of data collection

Question 43

Sampling error

Answer 43

discrepancy between the true population parameter and the sample statistics

Question 44

What happens if we do not know the actual population parameters

Answer 44

we can only estimate the probable sampling error

Question 45

True or false: the greater the n (sample size) the smaller the sampling error

Answer 45

true

Question 46

What does the selection of sample size depend on?

Answer 46

the research situation

Question 47

When is a pilot study used

Answer 47

to estimate the size of the phenomenon under study

Question 48

External validity

Answer 48

the extent to which the results of an investigation can be accurately generalized to other samples or situations

Question 49

Two types of external validity

Answer 49

population ecological

Question 50

Population validity

Answer 50

Generalizing the findings from the sample to the population from which it was drawn

Question 51

In population validity the _________ population may not be the same as the ________ population

Answer 51

accessible target

Question 52

Ecological validity

Answer 52

the extent to which the findings of a research study can be generalized to real-world settings or situations