Week 3

Investigation Skills

In the realm of agricultural science, the concentration of fertilizer plays a crucial role in determining plant growth and health. Fertilizers, containing essential nutrients such as nitrogen, phosphorus, and potassium, are applied to soil to enhance plant growth and productivity. However, the effectiveness of fertilizers can be influenced by various factors, including their concentration. Osmosis, the movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration, is a fundamental process in plant physiology that is intricately linked to fertilizer concentration. Understanding how osmosis interacts with fertilizer concentration is key to optimizing plant growth and agricultural productivity.

outlining the aim of the experiment

The aim of an experiment is written to succinctly express the purpose or objective of the investigation. It outlines what the researcher intends to achieve or discover through conducting the experiment. The aim statement should be clear, concise, and directly related to the focus of the experiment.

Task:

Read each aim statement carefully.

Evaluate each aim based on the following criteria:

Clarity: Is the aim easy to understand?

Specificity: Does the aim clearly outline what the experiment intends to investigate?

Relevance: Is the aim directly related to the experiment's focus on fertilizer concentration and plant growth?

Rate each aim as "Poor," "Fair," or "Good" based on your evaluation.

Provide a brief explanation for your rating for each aim.

Creating a testable hypothesis

Task:

Your task is to design a hypothesis for an experiment investigating the impact of varying concentrations of fertilizer on the growth of bean plants. Utilize the format "If [independent variable], then [dependent variable] will [increase/decrease/stay the same] because [reasoning]." Be sure to consider the principles of osmosis in your hypothesis formulation.

developing your variables table

Task: Identifying Variables and Controlled Variables in an Experiment on Fertilizer Concentration and Plant Growth

Your task is to identify the appropriate variables for an experiment investigating the effect of varying concentrations of fertilizer on the growth of bean plants. You will also define the independent and dependent variables using an explanatory phrase and identify several controlled variables. Follow the prompts below:

Independent Variable:

• Define the independent variable: (e.g., Concentration of fertilizer)

• Operational definition: (e.g., The amount of fertilizer, measured in grams, added to each pot of soil). Why do we need to do this? Can fertilizer be measured in multiple ways?

• What are the different levels or values of the independent variable? (e.g., 1g, 2g, 3g, 4g, 5g)

Dependent Variable:

• • • • Define the dependent variable: (e.g., Plant growth)

      • Operational definition: (e.g., Height of the bean plants, measured in centimeters, after a specified period)

      • How will you measure the dependent variable? (e.g., Using a ruler to measure the height of each bean plant)

Controlled Variables:

Identify at least three controlled variables to ensure a fair test. Consider the following prompts:

• • • • What environmental factors need to remain constant throughout the experiment? (e.g., Temperature, light intensity, humidity)

      • What other factors might influence plant growth that should be kept constant? (e.g., Type of soil, pot size, watering schedule)

      • How will you control these variables? (e.g., Using the same type of soil for all pots, placing pots in the same location with consistent light exposure)

Once you have identified these variables, you will have a solid foundation for designing and conducting your experiment to investigate the impact of fertilizer concentration on plant growth.

method

The method has 3 parts:

1. A list of EVERY material used, including numbers, sizes, and measuring equipment. This is in DOT POINTS

2. A scientific diagram of the experimental apparatus. Remember the RULES for scientific drawing!

3. Steps you did in the experiment. This needs to be in PAST TENSE, as it is a record of what you did, not a set of instructions but it also needs to be in PASSIVE VOICE (no "I's" or "We's"). The STEPS ARE NUMBERED in consecutive order so you DON'T USE temporal adverbs (first, next, then ...)

Still a bit confused? Here is a great explanation of a slightly different experiment: