The following is the outline of the factors relevant to the choice of statistical tests and a set of three charts that may be used to guide your selection of a test.

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Choosing the right statistical test depends on

Nature of the data

Sample characteristics

Inferences to be made

A consideration of the nature of data includes

Number of variables

Not for the entire study, but for the specific question at hand

Type of data

Numerical, continuous

Dichotomous, categorical information

Rank-order or ordinal

A consideration of the sample characteristics includes

Number of groups

Sample type

Normal distribution (parametric) or not (non-parametric)

Independent or dependent

A consideration of the inferences to be made includes

Data represent the population

The group means are different

There is a relationship between variables

Before choosing a statistical test, ask

How many variables?

How many groups?

Is the distribution of data normal?

Are the samples (groups) independent?

What is your hypothesis or research question?

Is the data continuous, ordinal, or categorical?

In situations where one variable is studied, the chart below may guide your selection of statistical tests.

In situations where two variables are studied, the chart below may guide your selection of statistical tests.

In situations where three or more variables are studied, the chart below may guide your selection of statistical tests.

In summary,

Statistical significance indicates the probability that results were chance findings

The choice of a statistical test depends on the data, sample characteristics, and research question

A one factor design (also known as a one-way ANOVA) is a statistical method used to determine if there are significant differences between the means of multiple groups. In this design, there is one independent variable (factor) with multiple levels or categories.

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Suppose $y_{ij}$ is the response is the $i$th treatment for the $j$th experimental unit, where $i=1,2,\cdots, I$. The statistical model for a completely randomized one-factor design that leads to a One-Way ANOVA is

$$y_{ij} = \mu_i + e_{ij}$$

where $\mu_i$ is the unknown (population) mean for all potential responses to the $i$th treatment, and $e_{ij}$ is the error (deviation of the response from population mean).

The responses within and across treatments are assumed to be independent and normally distributed random variables with constant variance.

One Factor Design’s Statistical Model

Let $\mu = \frac{1}{I} \sum \limits_{i} \mu_i$ be the grand mean or average of the population means. Let $\alpha_i=\mu_i-\mu$ be the $i$th group treatment effect. The treatment effects are constrained to add to zero ($\alpha_1+\alpha_2+\cdots+\alpha_I=0$) and measure the difference between the treatment population means and the grand mean.

Therefore the one way ANOVA model is $$y{ij} = \mu + \alpha_i + e_{ij}$$

Comparing means of multiple groups: When one wants to determine if there are significant differences in the mean of a dependent variable across different groups or levels of a factor.

Exploring the effect of a categorical variable: When one wants to investigate how a categorical variable influences a continuous outcome.

Assumptions of One-Factor ANOVA

Normality: The data within each group should be normally distributed.

Homogeneity of variance (Equality of Variances): The variances of the populations from which the samples are drawn should be equal.

Independence: The observations within each group should be independent of each other.

When to Use One Factor Design

When one wants to compare the means of multiple groups.

When the independent variable has at least three levels.

When the dependent variable is continuous (e.g., numerical).

Note that

If The Null hypothesis is rejected, one can perform post-hoc tests (for example, Tukey’s HSD, Bonferroni) to determine which specific groups differ significantly from each other.

Remember: While one-factor designs are useful for comparing multiple groups, they cannot establish causation.

Statistics is used as a tool to make appropriate decisions in the face of uncertainty. We all apply statistical concepts in our daily life either we are educated or uneducated. Therefore the importance of Statistics cannot be ignored.

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The information collected in the form of data (observation) from any field/discipline will almost always involve some sort of variability or uncertainty, so this subject has applications in almost all fields of research. The researchers use statistics in the analysis, interpretation, and communication of their research findings.

Some examples of the questions which statistics might help to answer with appropriate data are:

How much better yield of wheat do we get if we use a new fertilizer as opposed to a commonly used fertilizer?

Does the company’s sales are likely to increase in the next year as compared to the previous?

What dose of insecticide is used successfully to monitor an insect population?

What is the likely weather in the coming season?

Application of Statistics

Statistical techniques being powerful tools for analyzing numerical data are used in almost every branch of learning. Statistics plays a vital role in every field of human activity. Statistics has an important role in determining the existing position of per capita income, unemployment, population growth rate, housing, schooling medical facilities, etc in a country. Now statistics holds a central position in almost every field like Industry, Commerce, Biological and Physical sciences, Genetics, Agronomy, Anthropometry, Astronomy, Geology, Psychology, Sociology, etc are the main areas where statistical techniques have been developed and are being used increasingly.

Statistics has its application in almost every field where research is carried out and findings are reported. Application of statistics (by keeping in view the importance of statistics) in different fields as follows:

Social Sciences

In social sciences, one of the major objectives is to establish a relationship that exists between certain variables. This end is achieved through postulating hypothesis and their testing by using different statistical techniques. Most of the areas of our economy can be studied by econometric models because these help in forecasting and forecasts are important for future planning.

Plant Sciences

The most important aspect of statistics in plant sciences is its role in the efficient planning of experiments and drawing valid conclusions. A technique in statistics known as “Design of Experiments” helps introduce new varieties. Optimum plot sizes can be worked out for different crops like wheat, cotton, sugarcane, and others under different environmental conditions using statistical techniques.

Physical Sciences

The application of statistics in physical sciences is widely accepted. The researchers use these methods in the analysis, interpretation, and communication of their research findings, linear and nonlinear regression models are used to establish cause and effect relationships between different variables, and also these days computers have facilitated experimentation and it is possible to simulate the process rather than experimentation.

Medical Sciences

The interest may be in the effectiveness of new drugs, the effect of environmental factors, heritability, standardization of various records, and other related problems. Statistics come to the rescue. It helps to plan the next investigation to get trustworthy information from the limited resources. It also helps to analyze the current data and integrate the information with that previously existing.

How statistics is used by banks, insurance companies, Business and economic planning and administration, Accounting and controlling of events, Construction Companies, Politicians

Banks

Banks are a very important economic part of a country. They do their work on the guess that all the depositors do not take their money on the same day. Bankers use probability theory to approximate the deposits and claims to take out their money.

Insurance Companies

Insurance companies play an important role in increasing economic progress. These companies collect payment from the people. They approximate the death rate, accident rate, and average expected life of people from the life tables. The payment per month is decided on these rates.

Business

Business planning for the future is very important such as the price, quality, quantity, demand, etc of a particular product. Businessmen can make correct decisions about the location of the business, marketing of the products, financial resources, etc. Statistics helps a businessman to plan production according to the taste of the customers, the quality of the products can also be checked more efficiently by using statistical methods

The relationship between supply and demand is a very important topic of everyday life. The changes in prices and demands are studied by index numbers. The relation between supply and demand is determined by correlation and regression.

Economic Planning

Economic planning for the future is a very important problem for economists. For example (i) opening of new educational institutions such as schools, and colleges, revision of pay scales of employees, construction of new hospitals, and preparation of government budgets, etc. all these require estimates at some future time which is called forecasting which is done by regression analysis and the different sources of earning, planning of projects, forecasting of economic trends are administered by the use of various statistical techniques.

Accounting and Controlling of Events

All the events in the world are recorded, for example, births, deaths, imports, exports, and crops grown by the farmer etc. These are recorded as statistical data and analyzed to make better policies for the betterment of the nation.

Administrator

An administrator whether in the public or private sector leans on statistical data to provide a factual basis for appropriate decisions.

Politician

A politician uses statistical advantageously to lend support and credence to his argument while elucidating the problems he handles.

Construction Companies

All kinds of construction companies start and run their programs after making judgments about the total cost of the project (job, work). To guess the expenditure a very important statistical technique of estimation is used.

Biology

In biology correlation and regression are used for analysis of hereditary relations. To classify the organization into different classes according to their age, height, weight, hair color, eyebrow color, etc. the rules of classification are tabulation of statistics are used.

The post is about Multiple Choice Questions Related to Sampling and Sampling Techniques Quiz. There are 20 MCQs about Sampling Techniques covering the topics related, to stratified sampling, cluster sampling, and simple random sampling. Let us start with the Sampling Techniques Quiz.

Online Multiple Choice Questions about Sampling and Sampling Techniques with Answers

MCQs Sampling Techniques Quiz with Answers

Sample allocation plan that provides the most precision, given a fixed sample size is

In stratified random sampling with strata weights 0.35, 0.55, and 0.10, and standard deviations 16, 23, and 19, and sample sizes 70, 110, and 20, the variance of the sample mean estimator is?

A group consists of 300 people and we are interviewing all members of a given group called

When the procedure of selecting the elements from the population is not based on probability is known as

Problem of non-Response

If the respondents do not provide the required information to the researcher, then it is known as

If larger units have more probability of their inclusion in the sample, the sampling is known as

The cluster sampling method differs from the stratified sampling method in that

One similarity between the stratified sampling method and the cluster sampling method is that

In a cluster random sampling method

In a stratified random sampling method

Suppose that all the units in the population are divided into ten mutually exclusive groups. The word “mutually exclusive” means that

When the population is badly affected, which type of sampling is appropriate?

A randomly selected sample of 1000 college students was asked whether they had ever used the drug Ecstasy. Sixteen percent (16% or 0.16) of the 1000 students surveyed said they had which one of the following statements about the number 0.16 is correct?

Which ONE of the following is the main problem with using non-probability sampling techniques?

Which of the following is not a characteristic of quota sampling?

Before completing a survey, an individual acknowledges reading information about how and why the data they provide will be used. What is this concept called?

————- is a set of elements taken from a larger population according to certain rules.

The mean of clusters average is the biased estimator of a population mean when

Which of the following would usually require the smallest sample size because of efficiency?