Biostatistics is the science which deals with the plans and methods of collecting, tabulating, and analyzing numerical facts and figures in life processes. It deals with the methods of collection, tabulation and elementary analysis of data particular in the public health. Its objective is to acquire and be able to apply knowledge of the basic statistical methods and to critically evaluate statistics to their validity, reliability and to the right information.

Statistics is a science and a act of dealing with variations in such a way as to obtain reliable results. It deals with the manifestation and differences among persons, things, events or places despite the fact that all are classified under the same label.

The biological processes that can be measured in biostatistics are:
â€¢ Heartbeat - is the rate by which the heart pumps in one minute, the number of beats in one minute.
â€¢ Blood pressure- is the measurement of the pressure in the vessels
â€¢ Respiratory rate- is the number of respiratory cycles or chest rise in one minute
â€¢ Body temperature- measured by the thermometer
â€¢ Blood chemistry- is the quantitative evaluation of a volume of blood sample taken from an individual.

There are sciences related to Biostatistics. Biometrics is the science which is concern with the measurement of life span and life processes. Sociometry a science that involves the measurement of the way people live, their culture, opinions, attitudes as well as their relationship with one another. Psychometry is the science which is concern with the measurement of personality, mental growth and development of individual and groups and the way in which they adjust themselves to a changing environment.

Since biostatistics is a study of the population, it also deals with the study of population growth. There are different methods of computing for the population growth. It maybe done by direct head count which is called Census; or by Geometric method which is consists of mathematical approaches:

1) Linear Interpretation wherein the growth follows an arithmetic progression and there is an increase of population per unit time.
2) Geometric Change wherein the population decreases or increases at the same rate over its unit time.
3) Exponential Change a compounding type of change in which the compounding takes place at certain constant intervals.
4) Natural Increase and
5) Systematic Increase.

The population is estimated for analysis of various trends, for measuring shift in population, to determine the allocation of public funds or political representation in government centers, for planning and to estimate foreseeable community needs. The types of estimates and projection are; 1) total population, population of subdivision and population by selected characteristics. 2) Intercensal estimate, Postcensal estimate and Projection. 3) Curve-Fitting technique which requires three or more censuses if one is actually trying to locate a best curve. 4) Logistic Curve which implies a special mathematical model of growth to a human population. This technique is seldom used because it seldom fit the facts easily and its assumption about the future is very doubtful. 5) Apportionment Method is used primarily to estimate or project the population or certain population characteristics. 7) Survival Method is a technique for estimating migration and requires up-to-date life table values or accurate vital statistics and lastly, Ratio-Correlation technique which utilize several types of data which are symptomatic of change rather than a direct measure of change in the total population. It is used for estimating the population of subdivisions.

A sample population must be efficient and have the ability to yield the desired information. A sample population should also be a representative of the parent population so that interference from the sample can be generalized to that population with a measurable precision and confidence. It must be designed such that valid estimates of its variability can be made. Sample size should be adequate enough to minimize sample variability and to allow making estimates of the population characteristics with measurable precision. A sample population must have adequate coverage. It must be oriented towards the parent population and lastly, a sample population must be of the same of the parent population where it was selected.

Biostatistics plays a big role in the field of biology and Biotechnology because it describes the present population giving scientists an idea of what the needs of the people are and how to improve the way of living.