STPM Biology 964 cheat sheet
STPM Biology 964 · Keep the key ideas within reach.
Scientific Investigation and School-Based Assessment
A hypothesis is a testable statement predicting a relationship between the independent and dependent variables; it must be falsifiable.
Variables: independent variable is manipulated, dependent variable is measured, controlled variables are kept constant; operational definitions specify exactly how each is measured.
Validity means the experiment measures what it claims to measure; it requires appropriate controls and that only the independent variable affects the dependent variable.
Data presentation: tables with units in headings, line graphs for continuous data, bar charts for categorical data, scatter graphs for correlation; error bars show spread or uncertainty.
Statistical tests: t-test compares two means, chi-squared tests frequencies against expectation, correlation coefficient (r) measures linear association; state the null hypothesis and significance level (p = 0.05).
A good conclusion states the relationship supported by data, refers to the hypothesis, and discusses limitations and sources of error with suggested improvements.
Referencing and reporting: cite sources consistently, report raw data in an appendix, and avoid plagiarism by paraphrasing and acknowledging all sources.