Designing a Fair Test

Today was the first day of preparing our investigation on the effect of plant nutrient additives on plant growth.

STEP ONE: Method Described (Multistructural)

1. 180-190g of strained soil is weighed and added to a biodegradable punnet.
2. Three 2cm deep wells are made in the soil (evenly spaced out).
3. One sugar snap pea seed is put into each well. The wells are covered with soil.
4. 20mL of tap water is measured in a measuring cylinder then added evenly to the top of the soil.
5. The class's punnets are put in trays and placed in the window of the resource room.
6. 20mL of tap water will be added every Monday and every Friday.
7. The height of the plants will be recorded on Monday every week for 6 weeks.

We have yet to decide how to investigate the effect of the plant nutrient additives we have purchased - this is tomorrow's job!

STEP TWO: Variables Analysed (Relational)

Mr Nicoll identified some key variables that were controlled by using this method. We then discussed why it was important to control these variables:

Completing this HOTMap is our homework tonight.

OUR RESULTS