Planning, analysis and evaluation
Planning: state the independent, dependent and standardised (controlled) variables, how each is changed, measured or kept constant, and the range and intervals of the IV. Include a control (e.g. boiled enzyme) and repeats (at least 3). Assess risks. Statistical tests (with a null hypothesis of no difference/association): t-test compares two means; χ² compares observed with expected frequencies; Spearman's rank or Pearson's test correlation. If the calculated value is greater than the critical value at p = 0.05, reject the null hypothesis. Evaluation: validity (measures what it should, all other variables controlled), reliability/repeatability (consistent repeats), accuracy, precision; identify anomalies; suggest specific improvements (e.g. use a thermostatically controlled water bath).
≈ 50 min