2. Sources of Data
Sources from which the statistical data required for researches, studies and decision-making are collected are divided into two sources:
Chapter 1: GENERAL STATISTICAL TERMS
11.1.2 Stratified Sample
The population under investigation is divided into strata as per specific standards. Such strata are different from each other in terms of the characteristic measured. It should be considered that there should be more similarity between items in the same stratum than items of the whole population. The simple random sample method is applied in each strata. The stratified sample is often used in the case of heterogeneous communities.
Chapter 1: GENERAL STATISTICAL TERMS
11.1.4 Clustered Multi-Stage Random Sample
To select clustered multi-stage random sample items, population should be divided into primary units. A sample is chosen from these units as a first stage. Each unit of the selected primary units is divided into secondary units from which a sample is taken as a second stage. Each unit of the secondary units is divided into smaller units taken as a third stage, and so on until we get the required sample size. However, this type of sample is used when the population is large making it difficult to set a framework for all items, and the frame is only limited to secondary units; thus, we save a lot of effort and costs.
Chapter 1: GENERAL STATISTICAL TERMS
11.1.1 Simple Random Sample
Sampled items are taken depending on equal opportunities for all population units. Selection relies entirely on chance factors without any attempt to control the selection by the researcher. It is often used in proportionally harmonious populations with low degree of variation and difference between items.
Chapter 1: GENERAL STATISTICAL TERMS
10. Sample
A part of the statistical population selected as per the statistical inspection methods, provided that it will represent the population under investigation. To be representative of the population, the sample should include the characteristics of the population to draw valid conclusions about essential statistical characteristics of the population. .
Chapter 1: GENERAL STATISTICAL TERMS
4. Data Description
After collecting and presenting the data, the purpose of statistics is to study the well-studied phenomenon's essential characteristics to describe and measure it using specific measures that reflect such characteristics. One such measure used to describe a set of data is the measure of central tendency and measures of dispersion, skewness, moderation and kurtosis.
Chapter 1: GENERAL STATISTICAL TERMS
6. Population
All statistical units on which we want to carry out the statistical research. It is essential to clearly define such units so that they are combined under one characteristic or common characteristics. Most statistical populations consist of statistical units that change over time (renewable populations), while other populations are constant and do not change over time.
Chapter 1: GENERAL STATISTICAL TERMS
3. Data Presentation
The process follows data collecting and reviewing process. Such data is presented using several figures, whether in special statistical tables pre-prepared or represented using figures or graphics to compare different aspects of the well-studied phenomenon.
Chapter 1: GENERAL STATISTICAL TERMS
A. Quantitative Variable
It can be measured using the well-known quantitative measurements, like the age is measured in the number of years, the weight is measured in kilograms, the length is measured in meters, etc.
Chapter 1: GENERAL STATISTICAL TERMS
9. Complete Census
The statistical research method in which we study all community units under investigation without exception. This requires access to all statistical units to collect information related to them.
Chapter 1: GENERAL STATISTICAL TERMS
11. Types of Samples
Samples can be divided into two main categories:
Chapter 1: GENERAL STATISTICAL TERMS
5. Statistical Unit
The entity, item or section from which data is collected. It is called the counting unit that is used as a basis for data collection.
Chapter 1: GENERAL STATISTICAL TERMS
