Thinking Scientifically

The behavior of scientists when they study and investigate.

Picture a scientist in your mind…

Here are some real scientists

• Did you think of anyone like these two below?

Dr Hayat Sindi - She was the first

Saudi Muslim woman in the Middle

East to obtain a PhD in

biotechnology and today is a medical

scientist.

Now picture a place where they work…

Did anything like this come to mind?

The truth is you were born a scientist!

• All children are Scientists; the world is their laboratory

Being the best scientist you can be means…

• Being open-minded

• Being cooperative

• Being honest

• Experimenting ethically

• Treating others equally

• Communicating well with others

Scientific Method

• All scientists use this method –right?

Believe it or not…

• The scientific method is not used all that often!

• There is no one scientific method; different fields of science generally use different approaches to solving problems,

• “The Scientific Method” is a false construct, at best an oversimplification that usually misses the point of what scientists actually do.

True Scientific thinking means a few other things actually:

Some of which you already know!

Making observations

Qualitative Observation

Observation using the five senses to gather information about an object or event. Example: Describing a pencil as yellow.

• Taste

• Touch

• Hearing

• Sight

• Smell

Qualitative Observations

• Cannot be measured with a tool

• Is typically used to describe something,it is used to collect information

• It just cannot be “tested”

• An example: the caterpillar is fuzzy, orange and black

What kinds of things get observed?

• Science is about noticing events or things in your world and wondering why they happen

• A single word used to sum this is up is phenomena

• What is “phenomena”?

– They are observable events in nature (or our lives)

Make QUALITATIVE Observations now…

My qualitative observations

• The light reflects off of the water

• The water looks like a layer on top of the swimmer (like a blanket almost)

• The swimmer appears to be completely under the water’s surface

• The swimmer is dressed in swimming attire

• Share out yours!

What is this really a picture of?

• A swimmer just before she “breaks” the surface of the water.

Now – think of some questions that you have about this phenomenon (and write those down)

• How fast is she going?

• How fast is the shutter speed of the camera?

• Does this phenomenon happen every time?

• Why does the water’s surface texture change beneath her chin?

• How does the water feel as she swims??

Can I take my questions and make an experiment?

• Yes! This is the basis of science – observing a phenomena and finding out the answers to your questions!

• But not every question is “testable”

• For example, my first question “How fast is she going?” – is there a way we can figure this out?

• How?

Can I take my questions and make an experiment?

• My last question was “how does the water feel when she swims?”

• Is this testable?

• Some observations are more qualitative in nature and some can be changed to be quantitative. At this stage of learning science, make sure your questions are quantitative and measureable – if not re-write it!

Quantitative Observation

Observation using measurement

• Usually precise and specific

• using both standard and nonstandard measures or estimates to describe the dimensions of an object or event.

• Example: Using a meter stick to measure the length of a table in centimeters.

Here are my questions again – which ones are quantitative?

• How fast is she going?

• How fast is the shutter speed of the camera?

• Does this phenomenon happen every time?

• Why does the water’s surface texture change beneath her chin?

• How does the water feel as she swims??

More help with coming up with Questions:

• Use the idea of patterns to come up with questions.

Last step in this pre-experiment process:

Inference

• An explanation of an observation

• What are your assumptions?

• I assume this is an insect because it has six legs, and when I’ve seen insects before they have six legs.

• What have you seen before that reminds you of this?

• How can you find out?

On your page – make this chart:

Object/event observations

First Questions Quantitative Questions

Class Expectation:

• This is a class activity, so as such, you will follow these rules:

– Stay with your group and stay on task

– If you don’t understand the instructions, ask!

– Complete the activity to the best of your ability – work with others, but do not take their answers for your own!

Let’s go practice these skills

• Class vote – what area of the school do you want to go to?

…and we’re back!

• This little exercise is meant to get you started on the idea that all scientific endeavors begin with an observation, and then you begin to ask questions about that observation.

So how do we begin to test out those questions?We have to identify how to test these questions, and so we must understand parts of the experiment…

Variables

• Factors, conditions, and or relationships that can change or be changed in an event or system.

• Controlling

• Constant

• Independent

• Dependent

A birdy example…

Imagine you want to see what color of bird feeders your local birds preferred.

Red? Blue? Green?

Our Constants and Variables

• Independent Variable: color of the feeders

• Dependent Variable: amount of seed eaten

• Constants: everything else that is kept the same, for example:

– the location of the feeders

– the kind of feeder used

– putting the feeders out at the same time

Independent

• The independent variable in an experiment is the variable whose value the scientist changes in order to see what effect the changes have.

• A well-designed experiment has only one independent variable in order to maintain a fair test.

Dependent

• A dependent variable is what the experimenter observes to find the effect of changing the independent variable.

• You can have multiple dependent variables, it is often wisest to focus the experiment on one dependent variable so that the relationship between it and the independent variable can be clearly determined.

Our Experimental Design

Constants Location of feeders

Kind of seed

Type of feeder

Independent

Variable Red Blue Green

Dependent

Variable

Amount of Seed

Eaten

Amount of Seed

Eaten

Amount of

Seed Eaten

If everything except the independent variable is held constant, we can say:

The experiment is FAIR.

(ONLY the independent variable can change!)

Why is it important to only change the independent variable?

If you don’t…

If you measure a change in the dependent variable, you won’t know whether it is the independent variable that is causing the change.

Constant Variable

• Experimental constants are values that do not change either during or between experiments.

• Many natural forces and properties, such as the speed of light and the atomic weight of gold, are experimental constants.

Our Experimental Design

Constants Location of feeders

Kind of seed

Type of feeder

Independent

Variable Red Blue Green

Dependent

Variable

Amount of Seed

Eaten

Amount of Seed

Eaten

Amount of

Seed Eaten

Control variable

• A controlled variable is a variable that could change, but that the experimenter intentionally keeps constant (the same)

• For example, an experiment examining the relationship between how much sunlight plants receive (independent variable) and how tall they grow (dependent variable) should make sure none of the other factors change.

Control variable

• The experimenter should control how much water the plants receive and when, what type of soil they are planted in…

Control variable

• Can the amount of water the plants receive change?

• Sure, it can. But in order to determine what is actually changing in this experiment, you can’t change too many things at once – if you do, you don’t know what is actually causing growth!

To wrap it up:

Practice tonight!