What is Statistics?

Statistics is a branch of applied mathematics that deals with data collection, classification, analysis, and interpretation. The word statistics is derived from the Latin word ‘status’ means a ‘political state’ or ‘government’.

**What is Biostatistics?**

Biostatistics is a branch of biological science that deals with the study and methods of collection, presentation, analysis, and interpretation of data from biological research. Biostatistics earns the alternative name of biometrics due to its incorporation of numerous measurements and calculations. Within biostatistics, practitioners apply statistical methods to address biological problems. A basic understanding of biostatistics is necessary for studying biology, particularly doing research in biological science.

*The statistics will help the biologist to: *

*(1) Understand the nature of variability and *

*(2) Helps in deriving general laws from small samples.*

**Francis Galton** is called the ‘Father of Biostatistics’. He created the statistical concept ‘of correlation’. For the first time, Sir Galton used statistical tools to study differences among the human population. He also invented questionnaires and surveys to collect data on human communities. The term ‘**Biometry**’ was introduced by **Walter Weldon**.

**Statistics is classified into two categories:-**

**(1). **Pure Statistics

**(2). **Applied Statistics

**(1). Pure Statistics**

Pure statistics is the basic statistics. The pure statistics is further classified into FOUR sub-categories.

(a). Descriptive statistics

(b). Analytical statistics

(c). Inductive statistics

(d). Inferential statistics

**(a). Descriptive Statistics**

- These are the statistical tools and analyses which describe and summarize the main features of the data.
- Example: Measure of central tendency (mean, median, mode), Measure of dispersion (range, standard deviation, mean deviation) etc.
- The descriptive statistics explains the characteristics of the data.
- They reduce the complexities of the data into simple and logical summaries.

**(b). Analytical Statistics**

Analytical statistics deals with all statistical tools used to compare different variables.

- Analytical statistics helps to establish functional relationships between variables (data).
- Example: Correlation and Regression

**(c). Inductive statistics**

- Inductive statistics is the use of statistical tools to generate conclusions on the basis of random observations.

**(d). Inferential statistics**

- Inferential statistics is the application of statistical theories to analyze research problems.
- It Includes very complex calculations, analysis and comparisons.
- Examples: Index numbers, statistical quality control, vital statistics, etc.

**Classification of Biostatistics**:

Biostatistics is conventionally divided into two aspects:

**(1).** the design of experiments for getting or collecting the data.

**(2).** the statistical analysis or statistical method.

**Steps in biostatistics:**

A biostatistician investigation is carried out through the following sequential steps.

(1). Collection of data (variable)

(2). Classification of the collected data

(3). Analysis of data

(4). Interpretation of data

**Importance of Statistics in Biological Science**

Biostatistics has applications in all the branches of life sciences. Few applications of biostatistics are summarized below.

**(1). Research**

- Research is incomplete without the statistics
- Every result (data) in the research need to be statistically validated.
- For the design of experiments
- Selecting the method of collection of data
- Deriving logical conclusions from the data
- Deriving single values from a group of variables

**(2). Medical and Pharmaceutical Science:**

- For checking the efficiency of drugs
- To find out the possible side effects of drugs
- For conduction of drug treatment trials

**(3). Genetics:**

- Study the inheritance patterns of genes
- Essential for the study of Mendelian genetics
- To study the genetic structure of a population
- Studying the behavior of genes in a population
- For the mapping of chromosomes

**(4). In numerical taxonomy (taxonomy with numbers)**

**(5). For monitoring the community and public health**

**(6). Demography (study of human population)**

**(7). Statistics helps to implement policies by the government**

**(8). Used in weather forecasting**

**Limitations of Statistics**:

(1). Statistical laws are true on average. A single observation is not a statistic.

(2). Statistics cannot be applied to single/individual data.

(3). Statistical methods are best applicable to quantitative data.

(4). Statistical methods cannot be applied to highly heterogeneous data.

(5). The statistical results might be misleading if sufficient care is not exercised in collecting, analyzing, and interpreting the data.

(6). Only a person expert in statistics can handle the statistical tools efficiently.

(7). There are too many methods to study a single problem in statistics

(8). Statistics does not depict the entire story or the phenomenon.

(9). Statistical results are not always beyond doubt.

(10). Some errors are possible in the statistical decisions.

(11). We do not know whether an error has been committed.