Planning a practical

Planning a practical

What do we do first?

Open Ended

What's the first thing we do when planning a practical?

We start with a hypothesis!

• First- what am I looking for?

• Second- What do I predict will happen?

Open Ended

What will happen if I step from a large height with a piece of elastic cord strapped to me?

We start with a hypothesis!

• Question?

  What will happen if I step from a large height with a piece of elastic cord strapped to me?

• Prediction?

Multiple Choice

Spot the mistake

• The hypothesis is wrong- plants further away will grow more

• Both are incorrect

• The null hypothesis is wrong- plants grown further away from light should grow worse

• The null hypothesis is wrong- It should not make a prediction one way or the other

Open Ended

I want to investigate how water affects the growth of plants

•I take two identical plants

•I only water one, the other is left without water

•I keep light, heat and other conditions the same

What would be the hypothesis and null hypothesis for this experiment?

Multiple Choice

If one factor is responsible for change in another factor then it means there is causation.

True or False

• True

• False

Multiple Choice

Correlation or Causation?

The number of cold, snowy days and the amount of hot chocolate sold at a ski resort.

• Correlation

• Causation

Multiple Choice

Correlation or Causation?

The speed you drive and the amount of fuel you use

• Correlation

• Causation

Multiple Choice

Which example shows CORRELATION? (The events show correlation, but one thing does NOT cause the other thing to happen.)

• I put water in the freezer and now I have ice.

• The alarm clock went off and I woke up.

• Temperature and the amount of people at the beach.

What equipment should I use?

• You need to choose appropriate equipment for your investigation

• This might mean using equipment that is the right size, or provides precise enough measurements

Multiple Choice

What would be the most appropriate equipment for measuring out 375ml of water?

• Weighing scales

• 500 ml beaker

• 500 ml measuring cylinder

• 250ml beaker

Multiple Choice

What piece of equipment would you use to measure out accurately 25 cm3 of acid for an acid-base titration?

• Burette

• Pipette

• Beaker

• Measuring cylinder

We also need to consider safety issues- risk assess

• Assess the hazards

• What could cause harm?

• Assess the risks

• What is the harm, and what is the likelihood of it happening?

Multiple Choice

What is a hazard?

• Something that has the potential to cause harm

• The possibility that harm may occur

• Something that can make you fall over

Multiple Choice

Is this a risk or hazard? " Jumping into shark-infested waters".

• Risk

• Hazard

Multiple Choice

Puddle of water on the floor....is it a hazard or a risk?

• Hazard

• Risk

Multiple Choice

A risk assessment could be best defined as

• A systematic process of evaluating the potential risks that may be involved in an activity

• A situation involving exposure to danger

• The action of assessing someone or something

• Actions implementing risk evaluation decisions

We now need to look at the variables in our experiment

• Independent variable- the one you change

• Dependent variable- the variable that changes as a result of the independent variable

• Control variables- the ones you need to keep constant

We now need to look at the variables in our experiment

• Independent variable- the mass added

• Dependent variable- the time taken

• Control variables- distance, surface, same truck

Multiple Select

Dependent variables...

• are controlled by the scientist

• are the result of the independent variable--results of your experiment

• are kept the same in the experiment.

• are always going to be 0

Multiple Select

A scientist is testing which flavor of ice cream melts the fastest. What would his controlled variables be? (choose ALL that apply)

• The flavor of ice cream

• the bowl the ice creams are in

• the place in the room where the ice cream is

• the size of the scoop

• the time it takes to melt

Multiple Choice

If you were testing the time it took for objects of different sizes to reach the ground after being dropped from 30 feet in the air, which of these would be the DEPENDENT VARIABLE?

• The time it takes for each object to hit the ground.

• The size of each object.

• The type of object you use.

• The height you drop the object from

Multiple Choice

You are testing how the amount you water a plant affects its growth. What would be the INDEPENDENT VARIABLE in this experiment.

• They type of pot you put the plants in.

• The amount you water each plant.

• The amount of sunlight the plants get.

• The amount the plant grows.

Summary questions to finish!

In groups you are now going to:

Plan your own practical to investigate either:

-The effects of light on plant growth

-The effect of oxygen on plant growth

-The effect of classical music on plant growth

Template files are in the shared folder (unit 1)- the rest is up to you!