# Write briefly on the following terms A one tailed test, Systematic sampling, A two tailed test, Cluster sampling, Accidental / Haphazard Sampling

A one-tailed test: This type of statistical test involves making a directional prediction about the outcome. For instance, it could be predicted that students who engaged in micro-teaching will achieve higher scores in practical teaching compared to those who did not participate.

Systematic sampling: In this method of sampling, a sample is chosen by selecting every Kth element from a population list. Unlike other sampling techniques, not all members have an equal chance of being chosen. Once the starting point and interval (K) are set, the remaining elements for the sample are automatically determined.

A two-tailed test: This form of statistical test is non-directional and focuses on the difference between the means of two samples. An example of a two-tailed test is a null hypothesis, which posits that there is no significant difference between the two groups being compared.

Cluster Sampling: When obtaining a list of all members of a widely spread population, such as primary school children in Nigeria, is impractical, cluster sampling is used. In this method, groups, rather than individual members, are randomly selected for the study. The selected groups share common characteristics.

Accidental/haphazard sampling: This type of sampling involves selecting members of a population based on their availability and willingness at a given time until the desired sample size is reached. Fields like press, journalism, astronomy, pharmacy, and medicine often use this method, where representativeness isn’t the primary consideration.

A one-tailed test: In a one tailed or directional test, a prediction is made as to what

to expect. Example is:

A one-tailed test is concerned about superiority/inferiority of two groups. “Students who participated in micro-teaching will score higher in practical

teaching than those who did not” Systematic sampling: This procedure involves drawing a sample by taking every Kth case from a list of the population. Thus, the major difference between the systematic sampling and the other types of sampling is the fact that all members of the population do not have an independent chance of being selected for the sample. Once K is determined and the first kth element decided then, the rest of the individuals to be included in the sample are automatically determined. A two-tailed test: unlike a one-tailed test, a two-tailed test is a non-directional test that is only interested in the difference between the means of two samples. A null

hypothesis is a good example of a two-tailed test:

Cluster Sampling: It is impracticable to obtain or compile a list of all the members of a population say primary school children in Nigeria. The cost of studying subjects of a population that spans a very wide geographical area is prohibitive. Cluster sampling is the kind of sampling in which groups, not individuals are randomly selected. All the members of the selected groups have the same characteristics. Accidental/haphazard sampling: This implies choosing any member of the population that is available at the given time until the desired number is achieved. Participation here is based on availability and willingness. Pressmen, Journalists, Astronomists, Pharmacists, Medical Practitioners are some of the fields where representativeness is not the driving force.

[mediator_tech]

**2. (a) Explain educational statistics (b) Is statistics really needed in education? Discuss**

**Evaluation**

1. A one-tailed test involves making a __________ prediction about the outcome.

a) random

b) directional

c) non-directional

2. A one-tailed test focuses on the __________ of two groups.

a) similarity

b) superiority/inferiority

c) equality

3. Systematic sampling selects every __________ element from a population list.

a) random

b) Kth

c) alternate

4. In systematic sampling, not all members of the population have an __________ chance of being selected.

a) equal

b) independent

c) unbiased

5. A two-tailed test is interested in the __________ between the means of two samples.

a) direction

b) similarity

c) difference

6. A null hypothesis is an example of a __________ test.

a) one-tailed

b) two-tailed

c) non-directional

7. Cluster sampling selects groups, not __________, from a population.

a) individuals

b) objects

c) animals

8. Cluster sampling is useful when the population is spread across a __________ geographical area.

a) small

b) wide

c) familiar

9. All members of selected groups in cluster sampling share __________ characteristics.

a) different

b) unique

c) common

10. Accidental/haphazard sampling chooses members based on __________ and willingness.

a) financial status

b) availability

c) expertise

11. Accidental/haphazard sampling is often used in fields where __________ is not a priority.

a) accuracy

b) representativeness

c) availability

12. Cluster sampling is suitable when compiling a list of all members of a population is __________.

a) easy

b) challenging

c) unnecessary

13. Systematic sampling involves selecting every __________ element.

a) odd

b) even

c) Kth

14. A one-tailed test predicts a specific __________ of an outcome.

a) range

b) direction

c) probability

15. A two-tailed test focuses on the __________ between the means of two samples.

a) similarity

b) difference

c) prediction