LESSON 3

Question 1

Types of POPULATION

Answer 1

• Target Population
• Accessible Population

Question 2

The group defined by the researcher’s specific interests. Individuals in a _______ typically share one characteristic.

Answer 2

Target Population

Question 3

The part of the target population that can be accessed by the researchers.

Answer 3

Accessible Population

Question 4

The entire set of individuals who have the characteristics required by the researcher.

Answer 4

The Target Population ( The Population)

Question 5

A portion of the target population consisting of individuals who are accessible to be recruited as participants in the study.

Answer 5

The Accessible Population

Question 6

The individuals who are selected to participate in the research study.

Answer 6

The Sample

Question 7

HOW DO WE MAKE SURE THAT THE STATISTICS AND INFERENCES CAN BE GENERALIZED TO THE POPULATION?

The _______ of a sample refers to the extent to which the charactreristics of the sample accurately reflect the characteristics of the population.

Answer 7

Representativeness

Question 8

A _______ is a sample with the same characteristics as the population.

Answer 8

Representative Sample

Question 9

A ______ is a sample with different characteristics from those of the population.

Answer 9

Biased Sample

Question 10

_______ or “sampling bias” occurs when participants or subjects are selected in a manner that increases the probability of obtaining a biased sample.

Answer 10

Selection Bias

Question 11

The process of selecting individuals for a study is called _______.

Answer 11

Sampling

Question 12

Researchers have developed a variety of different _______ (also calles “sampling techniques” or “sampling procedures”)

Answer 12

Sampling Methods

Question 13

Two types of Sampling Technique

Answer 13

1. Probability Sampling (all has equal chances)
2. Non-Probability Sampling (not all has the chance to be selected)

Question 14

In _______, the entire population is known, each individual in the population has a specifiable probability of selection, and sampling occurs by a random process based on the probabilities.

Answer 14

Probability Sampling

Question 15

In _______, the population is not completely known, individual probabilities cannot be known, and the sampling method is based on factors such as commonsense or ease, with an effort to maintain representativeness and avoid bias.

Answer 15

Non-Probability Sampling

Question 16

Probability Sampling Techniques

Answer 16

1. Simple Random Sampling
2. Systematic Sampling
3. Stratified Random Sampling
4. Proportionate Stratified Random Sampling
5. Cluster Sampling

Question 17

The basic requirement for random sampling is that each individual in the population has an equal chance of being selected. Equality means that no individual is more likely to be chosen than another. A second requirement that is sometimes added is that each selection is independent of the others. Independence means that the choice of one individual does not influence or bias the probability of choosing another individual.

Answer 17

Simple Random Sampling

Question 18

Process of Simple Random Sampling :

Answer 18

1. Clearly define the population from which you want to select a sample.
2. List all the members of the population.
3. Use a random process to select individuals from the list.

Question 19

2 Principal Methods of Random Sampling

Answer 19

1. Sampling with replacement ( the chance is constant )
2. Sampling without replacement ( others can have their chance )

Question 20

_______ is a type of probability sampling that is very similar to simple random sampling. ______- begins by listing all the individuals in the population, then randomly picking a starting point on the list. The sample is then obtained by moving down the list, selecting every nth name.

Answer 20

Systematic Sampling

Question 21

We first identify the specific subgroups (or strata) to be included in the sample. Then we select equal-sized random samples from each of the pre-identified subgroups, using the same steps as in simple random sampling. Finally, we combine the subgroup samples into one overall sample.

Answer 21

Stratified Random Sampling

Question 22

As with a stratified sample, we begin by identifying a set of subgroups or segments in the population. Next, we determine what proportion of the population corresponds to each subgroup. Finally, a sample is obtained such that the proportions in the sample exactly match the proportions in the overall population.

Answer 22

Proportionate Stratified Random Sampling

Question 23

_______ is a probability sampling method in which you divide a population into clusters, such as districts or schools, and then randomly select some of these clusters as your sample.

Answer 23

Cluster Sampling

Question 24

Non-Probability Sampling Techniques

Answer 24

1. Convenience Sampling
2. Quota Sampling
3. Network Sampling/Snowball Sampling

Question 25

In _______, researchers simply use as participants those individuals who are easy to get. People are selected on the basis of their availability and willingness to respond.

Answer 25

Convenience Sampling

Question 26

_______ is a non-probability sampling method that relies on the non-random selection of a predetermined number or proportion of units.

Answer 26

Quota Sampling

Question 27

______ is a non-probability sampling method where new units are recruited by other units to form part of the sample. _______ can be a useful way to conduct research about people with specific traits who might otherwise be difficult to identify.

Answer 27

Network Sampling/Snowball Sampling

Question 28

A sample is obtained using a random process to select participants from a list containing the total population. The randm process ensures that each individual has an equal and independent chance of selection.

Answer 28

Simple Random

Question 29

A sample is obtained by selecting every nth participant from a list containing the total population after a random start.

Answer 29

Systematic

Question 30

A sample is obtained by dividing the population into subgroups (strata) and then randomly selecting equal numbers from each subgroups.

Answer 30

Stratified Random

Question 31

A sample is obtained by subdividing the population into strata and then randomly selecting from each stratum (single) a number of participants so that the proportions in the sample correspond to the proportions in the population.

Answer 31

Proportionate Stratified

Question 32

Instead of selecting individuals, a sample is obratined by randomly selecting clusters (preexisting groups) from a list of all the clusters that exist within the population.

Answer 32

Cluster

Question 33

A sample is obtained by selecting individual participants who are easy to get.

Answer 33

Convenience

Question 34

A sample is obtained by identifying subgroups to be included, then establishing quotas for individuals to be selected through convenience from each subgroup.

Answer 34

Quota

Question 35

Strength and Weaknesses The selection process is fair and unbiased, but there is no guarantee that the sample is representative.

Answer 35

Simple Random

Question 36

Strength and Weaknesses An easy method for obtaining an essentially random sample, but the selections are not really random or independent.

Answer 36

Systematic

Question 37

Strength and Weaknesses Guarantees that each subgroup will have adequate representation, but the overall sample is usually not representative of the population.

Answer 37

Stratified random

Question 38

Strength and Weaknesses Guarantees that the composition of the sample (in terms of the identified strata) will be perfectly representative of the composition of the population, but some strata may have limited representation in the sample.

Answer 38

Proportionate Stratified

Question 39

Strength and Weaknesses An easy method for obtaining large, relatively random sample, but the selections are not really random or independent.

Answer 39

Cluster

Question 40

Streangth and Weaknesses An easy method for obtaining a simple, but the sample is probably biased.

Answer 40

Convenience

Question 41

Strength and Weaknesses Allows a researcher to control the composition of a convenience sample, but the sample probably is biased.

Answer 41

Quota