The Scientific process

Review of HSW

Scientists come up with theories- then test them

• Science is about explaining HOW and WHY things happen.

• It is about seeking and gaining KNOWLEDGE from the world around us.

• Scientists gain this knowledge by ASKING QUESTIONS and TESTING them.

Scientists come up with theories- then test them

1. Make an OBSERVATION2. ASK a question (HOW or WHY does this happen?)3. SUGGEST an answer by forming a THEORY. Scientists

may also form a MODEL (a simplified picture of what is physically going on)

4. Make a PREDICTION or a HYPOTHESIS- this is a specific, testable statement.

5. Carry out a TEST to provide EVIDENCE to support the prediction

1. The ivy is darker green on one wall than another.

Observation Question Theory Hypothesis Test

2. The brown beetles are less common than the green ones.

Observation Question Theory Hypothesis Test

3. Five people who were admitted to hospital with food poisoning on Saturday had consumed “Tasty” doughnuts the day before.

Observation Question Theory Hypothesis Test

Remember..

A theory is only scientific if it can

be TESTED

...Then they tell everyone else about their results

1. Scientists produce a REPORT (a write-up) of their investigation.

2. This will undergo PEER REVIEW: it will be sent out to other scientists who are experts in the same area. They examine the data and results.

3. If the other scientists think the conclusion is reasonable the report will be published in a JOURNAL.

4. Peer review cannot guarantee the science is correct: other scientists still need to REPRODUCE it.

5. Sometimes mistakes are made and FLAWED work is published.

...Then other scientists will test the theory too

When other scientists in the same area read the published theories and the results of the investigationsthey will try to test the theory themselves.

1. They repeat the experiment in EXACTLY THE SAME WAY.

2. This may lead to them making NEW THEORIES and testing these with NEW EXPERIMENTS

If the evidence supports the theory it will be accepted....

1. If every scientist carries out experiments that support the theory it is thought of as being SCIENTIFIC FACT

2. But it will never become TOTALLY INDISPUTABLE. 3. New breakthroughs or advances could provide new

ways to question or test the theory.4. NEW EVIDENCE may CONFLICT with the current

evidence and the testing may have to start all over again...

Where does evidence come from?

Evidence comes from...

Lab experiments1. In the lab all

variables can be controlled.

2. This means you can draw meaningful conclusions.

Well designed studies1. Some things can’t be

investigated in the lab.2. All variables in the study

must still be controlled as much as possible.

3. Using matched groups who are as similar as possible may help to control all the variables that might have an effect.

....Society MAKES DECISIONS based on scientific evidence

1. Lots of scientific work often leads to IMPORTANT DISCOVERIES that could BENEFIT SOCIETY.

2. These results are used to MAKE DECISIONS about the way we live.

3. All sections of society use science to make decisions.

But other factors can affect the way the science is used...

There may be conflict between the recommendations produced in the research and other factors. These factors may be...

Economic

Social

Environmental

Economic Factors

Society has to consider the COST of implementing changes based on scientific conclusion.Scientific research is also expensive to carry out.

EXAMPLE?

Social Factors

Decisions may affect the way we live.People may not like the recommendations that are made.

EXAMPLE?

Environmental

There may be a conflict between what the recommendations are and what people consider to be “good for the environment”

EXAMPLE?