Biostatistics and Data Handling

Chapter Overview

Biostatistics is the application of statistical methods to design experiments and analyze data in biology, medicine, and public health. Core descriptive statistics include measures of central tendency (mean, median, and mode) and measures of dispersion. Range represents the difference between maximum and minimum values, while standard deviation (SD) quantifies the amount of variation or dispersion of a set of values from the mean. Percentile indicates the value below which a given percentage of observations fall.

Data visualization is crucial for interpreting biological results. The chapter guides students on constructing bar charts and pie charts with proper titles, labeled axes, legends, and units. Sketching error bars on bar charts based on standard deviation or range is emphasized to visually indicate data reliability and statistical significance. A well-designed graph immediately communicates the variability and strength of experimental findings.

Scientific investigations require rigorous experimental design. This includes establishing an experimental group and a control group (to provide a baseline for comparison). Researchers must identify and manage variables: independent variables (manipulated factors), dependent variables (measured outcomes), and controlled variables (held constant to prevent bias). These principles are demonstrated through three key experiments: 1) Effect of light intensity on plant growth, 2) Effect of water amounts on plant growth, and 3) Effect of pH levels on enzyme activity. Mastering these research concepts is vital for HSSC-II SLO-based assessments.