LEC 2 Flashcards
___________ is the most commonly used sampling technique in which each member in the population is given an equal chance of being selected in the sample.
Random sampling
keyword: equal chance
________ is a method of collecting a small portion of the population by which not all the members in the population are given the chance to be included in the sample.
Non-random sampling
keyword: not all
Properties of Random Sampling
- Equiprobability
Random sampling is usually called _____ sampling while non-random sampling is a ____ sampling.
bias sampling
Properties of Random Sampling
- Equiprobability
- Independence
Two Kinds of Random Sampling
- Restricted Random Sampling
- Unrestricted Random Sampling
_________ involves certain restrictions intended to improve the validity of the sampling.
Restricted Random Sampling
This design is applicable only when the population being investigated requires _________.
homogeneity
_________ is considered the ____ random sampling design because there were no restrictions imposed and every member in the population has an equal chance of being included in the sample.
Unrestricted Random Sampling
Sampling Techniques
a. Random Sampling Techniques
b. Non-random Sampling Technique
Random Sampling Techniques
- Lottery or Fishbowl Sampling
- Sampling with the use of Table of Random
- Systematic sampling
- Stratified random sampling
- Multi-stage or Multiple Sampling
Non-random Sampling Techniques
- Judgement or Purposive Sampling
- Quota Sampling
- Incidental Sampling
This is done by simply writing the names or numbers of all the members of the population in small rolled pieces of paper which are later placed in a container. The researchers shakes the container thoroughly then draws n out of N pieces of papers as desired for a sample.
Lottery or Fishbowl Sampling
If the population is large, a more practical procedure is the use of table of random numbers which contains rows and columns of digits randomly ordered by a computer.
A sample size n can be generated by beginning at an arbitrary points in table of random numbers, closing your eyes and haphazardly pointing at an entry in the table then proceed in any direction until n distinct
Sampling with the use of Table of Random
This method of sampling is done by taking every kth element in the population. It applies to a group of individuals arranged in a waiting line or in a methodical manner.
For instance, the objective is to get the opinion of employees regarding employee-management relations, a sample of size n will be selected from a list of employees arranged alphabetically or by age, experience, positions or academic rank.
Systematic Sampling
When the population can be partitioned into several strata or subgroups, it may be wiser to employ the stratified technique to ensure a representative of each group in the sample.
Stratified random sampling
Random samples will be selected from each stratum. Selecting a sample with this technique is quite difficult and costly since it requires a complete listing, called frame, of all elements in the population.
Stratified random sampling
2 Types of Stratified Random Sampling
a. Simple stratified random sampling
b. Stratified proportional random sampling
_________ is when the population is grouped into more or less homogenous classes, that is, different groups but with a relatively common characteristic, then each can be sampled independently by taking equal number of elements from each stratum.
Simple stratified random sampling
In some cases, the characteristics of the population is such that the proportions of the subgroups are grossly equal. The researchers may wish to maintain this characteristic in a sample with the use of the _____ _____technique.
Stratified Proportional random sampling
This method is an extension or a multiple application of the stratified random sampling technique. The number of stages depends on the number of population and the sample size needed in the survey.
Multi-stage or Multiple Sampling
This technique uses several stages or phases in getting the sample from the population. However, selection of the sample is still done at random.
Multi-stage or Multiple Sampling
Non-random Sampling Techniques
a. Judgement or Purposive Sampling
b. Quota Sampling
c. Incidental Sampling
d. Convenience Sampling
This method is also referred to as non-random or non-probability sampling.
Judgement or Purposive Sampling
It plays a major role in the selection of a particular item and/or in making decisions in cases of incomplete responses or observation. This is usually based on a certain criteria laid down by the researcher or his adviser.
Judgement or Purposive Sampling
This is a relatively quick and inexpensive method to operate since the choice of the number of persons or elements to be included in a sample is done at the researcher’s own convenience or preference and is not predetermined by some carefully operated randomizing plan.
Quota Sampling
This design is applied to those samples which are taken because they are the most available. The investigator simply takes the nearest individual as subjects of the study until it reaches the desired size.
Incidental Sampling
This method has been widely used in TV and radio programs to find out opinions of TV viewers and listeners regarding a controversial issue.
While the issue is being discussed in a talk show, the hosts will immediately get responses and comments from those who will call their telephone operators.
This method is ____ against those without telephones in their houses.
bias
