Cover lesson · Food and Nutrition · Year 11 · Advanced
DCF: Data and computational thinking → Data and information literacy
Name: Class: Date:
What this practises: GCSE Food and Nutrition (Made-for-Wales, teaching from 2025), Unit 2: Food Investigation, 2.3.2 Collecting, analysing and presenting results (tables, bar charts, star diagrams, validity and reliability) and 2.3.3 Reflection and evaluation (drawing conclusions, evaluating results), using the starch science in 2.1.3 (gelatinisation). It uses an invented pupil’s investigation. This is practice only, not NEA work. Pupils must not work on their own Unit 2 investigation in this lesson, and nothing they write today goes into their NEA folder.
Print: this sheet, one per pupil, and the stimulus sheet “Cornflour sauce investigation: results pack”, one between two. Pupils need a calculator, a ruler and two coloured pencils. The taste panel data is also in cornflour-sauce-taste-panel.csv if you are in a computer room, but paper is fine. No cooking today.
Run: 7 min pupils read the results pack in pairs · 8 min Step 2, the means and the anomaly · 11 min Step 3, the bar chart and the trend · 8 min Step 4, the star diagram · 12 min Step 5, the conclusion, alone and in silence · 9 min Step 6, validity and reliability. Total 55 minutes.
Collect: this sheet. The class teacher has a worked example and answer key.
Cerys has investigated how the amount of cornflour changes a sweet white sauce. She has collected her results but has not analysed them yet. You are going to do the analysis for her: work out the means, deal with an odd result, present the data as a bar chart and a star diagram, decide whether her hypothesis was right, and judge how far her results can be trusted. These are the same skills you use in the Unit 2 Food Investigation.
Key words:
Read all four sections. Underline anything in the method or the lab notes that might have affected the results.
(a) Work out the mean line spread for each sauce, to 1 decimal place.
| Cornflour | Mean of all 3 batches (mm) | Mean without any anomaly (mm) |
|---|---|---|
| 5 g | ||
| 10 g | ||
| 15 g | ||
| 20 g |
(b) Which result is the anomaly? Use the lab notes and the science to explain why it happened and why it should be left out.
(c) Work out the mean taste panel scores for the 20 g sauce, to 1 decimal place.
| Thickness | Smoothness | Sweetness | Glossiness | Starchy taste |
|---|---|---|---|---|
(a) Draw a bar chart of the mean line spread for each sauce, using your means without the anomaly. Use a ruler. Write the value on top of each bar.
(b) Describe the pattern. Use at least two figures, including the percentage fall in spread from the control (10 g) to 20 g. Does the spread fall by the same amount each time you add 5 g of cornflour?
Plot the mean scores for the 10 g sauce in one colour and the 20 g sauce in another. Mark each score on its line, join the dots, and add a key.
Key: = 10 g = 20 g
Name the two biggest differences between the two sauces, with figures.
On your own, in silence. Cerys’s hypothesis has three parts. For each one, say whether the results support it, partly support it or do not support it, and give the evidence. Use the preference ranking: count first choices, and add up each sauce’s ranks (the lowest total is the most preferred).
| Part of the hypothesis | Verdict | Evidence (figures and quotations) |
|---|---|---|
| More cornflour makes the sauce thicker, so it spreads less. | ||
| The 20 g sauce will be too thick and lumpy. | ||
| Tasters will prefer the 10 g sauce. |
Explain the thickening using the science of gelatinisation, then rewrite the hypothesis so that it fits the evidence.
Find three problems with how Cerys collected her results. Say whether each one affects validity or reliability, and how to fix it.
| Problem | Validity or reliability? | Improvement | |
|---|---|---|---|
| 1 | |||
| 2 | |||
| 3 |
Name one thing Cerys did well that makes her line spread results more reliable.