Begin by framing the research question exactly as written and state its importance in your introduction: explain why chlorophyll-a concentration in phytoplankton matters for pond ecology and why shading is a plausible driver. Outline your hypothesis (both null and alternative) based on light limitation of photosynthesis. Describe the experimental design clearly: three shading treatments (0%, 50%, 80%) in 20 L mesocosms, with at least three replicates per treatment, randomized placement at Riverside High School pond, and a four-week sampling schedule (e.g., twice weekly). List all control variables (volume, initial water source, mesocosm material, initial phytoplankton inoculum if used, temperature monitoring, nutrient additions or lack thereof) and say how you will keep them constant. Include permissions and safety considerations for working at the school pond and note any ethical approvals needed for field work. In your methods write-up use the narrative, impersonal tone required by the IB (e.g., âSamples were collectedâŠâ) and provide specific details for sample collection, preservation, and transport to minimise degradation.
For measurement and data quality, describe the method you will use to determine chlorophyll-a (for example, fluorometric measurement or spectrophotometric extraction using acetone), include instrument models, wavelengths, calculation equations and units (”g Lâ1). State calibration procedures, blank and standard controls, and how you will estimate and report measurement uncertainty for each instrument (pipettes, balances, spectrophotometer/fluorometer). Record supporting environmental data at each sampling (light intensity under each shade, water temperature, pH, dissolved oxygen, and any visible algal blooms) so you can explain variation. Plan your data processing steps: raw tables, mean and standard deviation for replicates, conversion calculations, and any data transformations required to meet test assumptions.
In your analysis and write-up, describe the statistical tests you will use to answer the research question: check assumptions, use one-way ANOVA to test differences among shading treatments and appropriate post-hoc tests (e.g., Tukey) if ANOVA is significant; report effect sizes and confidence intervals. Include graphical presentation (mean chlorophyll-a vs shading level with error bars, time-series plots for each treatment) and state how you will interpret R2 or p-values. In the conclusion and evaluation, link findings back to the research question and hypothesis, discuss limitations (replication, temporal scale, mesocosm artefacts), suggest realistic improvements, and compile full in-text citations and a bibliography in a consistent style. Ensure the final IA respects the ESS structure and word count requirements, clearly labels tables/figures with units, and integrates numerical evidence into your discussion rather than only descriptive statements.