Formative Assessment Practical Set-Up

Navigate the knowledge tree: 🌿 Biology ➡ NCEA Level 2 Biology ➡ 2.1 Investigation ➡ Lesson 6: Formative Assessment Practical Set-Up

Learning Intentions

By the end of this topic, you should be able to:

Determine the aim and write a testable hypothesis for the method provided.
Identify the independent, dependent, and control variables in the method provided.
Follow the method closely to set up the osmosis investigation correctly.
Check my set-up to reduce errors and improve reliability.

Glossary

Key terms and definitions.

word: Definition

Method for the Osmosis in Kūmara Investigation

Identify the variables in the method provided

Remember, that the investigation aims to determine the relationship between the independent and dependent variable, but only if the control variables are kept the same.

Independent variable

The one thing you change on purpose, and usually appears on the x-axis of a graph.

Dependent variable

The thing you measure, and usually appears on the y-axis of a graph. It may or may not change because of the independent variable

Control variables

Things you keep the same to keep the test fair. It prevents other factors from affecting the results.

Determine the aim and write a testable hypothesis for the method provided

Remember that there are two types of errors that could weaken the accuracy or reliability of your results. You must identify these and figure out what you will do to minimise the effect of these sources of error.

What's the aim?

The aim clearly states what the investigation is trying to find out. It must include:

The independent variable (what is changed).
The dependent variable (what is measured).

What's a hypothesis?

A hypothesis is a testable prediction based on scientific ideas (osmosis). A strong hypothesis:

Links the independent and dependent variables.
Explains why the change is expected (or not).

Identify the possible sources of error in this method provided

What are the potential sources of systematic errors?

Systematic errors cause results to be consistently too high or too low. They affect accuracy, not reliability.

As a result of systematic errors, results may:

Appear consistent, but are in fact not the true value (are wrong).
Create trends that look valid (true) but are inaccurate.

What are the potential sources of random errors?

Random errors cause results to vary unpredictably between repeats. This lowered precision affects reliability, not accuracy.

As a result of systematic errors, results may:

Be scattered with the pattern much harder to see.
Have means that are still accurate, but the data is less reliable.

For the osmosis investigation, these are the specific errors you must consider:

More on Title

📕 article 📸 image 🎮 interactive 🎦 video

How to investigate osmosis (BBC Bitesize)

Glossary

Key terms and definitions.

word: Definition

Practice Tasks for Different Thinking Skills

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