Basic Concepts
1 Definitions
Statistics is the branch of science that deals with the collection, summarization, analysis, and interpretation of data.
Biostatistics is the application of statistics to data collected from experiments in the field of biological sciences or medicine.
2 Population and Sample
2.1 Population
A population can be defined as the largest group of entities (people, animals, plants, etc.) that we are interested in studying or drawing conclusions about.
Population can be finite or infinite.
The units of a population are termed as observations.
2.2 Sample
A sample is a subset of the population.
It is used to draw conclusions about the population because collecting data from the entire population is often impractical, costly, and time-consuming, particularly when the population is extremely large.
2.3 Example
If we are interested in evaluating the effect of a new medication on lowering blood glucose levels in diabetic patients:
The population would be all diabetic patients, however, it is not feasible to collect data from all diabetic patients.
Therefore, we would collect data from a representative part of diabetic patients (sample).
The data collected from this sample can be used to draw conclusions about the effect of the medication on the entire population of diabetic patients.
3 Main areas of statistics
Descriptive statistics:
It is used to summarize and describe data collected from a sample or population.
It includes measures of central tendency (average), measures of dispersion (spread), and graphical representation of data.
Inferential statistics:
It is used to draw conclusions (i.e., make inferences) about a population based on data collected from a sample drawn from that population.
It includes hypothesis testing, confidence intervals, and other statistical methods.
4 References
Daniel, W. W. and Cross, C. L. (2013). Biostatistics: A Foundation for Analysis in the Health Sciences, Tenth edition. Wiley
Heumann, C., Schomaker, M., and Shalabh (2022). Introduction to Statistics and Data Analysis: With Exercises, Solutions and Applications in R. Springer
Lane, D. M. et al., (2019). Introduction to Statistics. Online Edition. Retrieved September 14, 2024, from https://openstax.org/details/introduction-statistics