Chapter 2

Question 1

Investigating includes

Answer 1

Observation and performing of experiments

Question 2

Define Scientific method

Answer 2

The scientific methods is a systematic collection and classification of data, and the making and testing of a hypotheses based on data.

Question 3

Hypothesis

Answer 3

A possible explanation to account for the observations

Question 4

Data

Answer 4

Observations and measurements; the results of an experiment

Question 5

Define Theory

Answer 5

A hypothesis becomes a theory when there is an overwhelming amount of evidence to support it.

Question 6

Define A Fair Test

Answer 6

A fair test is a test which controls all variables in an experiment except one; which is the one being tested, when in an attempt to answer the scientific question

Question 7

Define Experimental/Human Error

Answer 7

A mistake by the human conductor of the experiment. They can however be avoided with sufficient care and checking.

Question 8

Define Random Error

Answer 8

An error in an experiment due to the limits to the precision of the measurement

Question 9

Define Systematic Error

Answer 9

An error that occurs in the experiment because of the way in which the experiment was designed.

Question 10

Define Ethics

Answer 10

Moral principles and values

Question 11

Define ethical behaviour

Answer 11

A behaviour that conforms to a set of moral principles and values

Question 12

Define placebo

Answer 12

An inactive substance that looks like the real medications, in a medical experiment

Question 13

Define placebo effect

Answer 13

A change or improvements in patients who are given a placebo or a ‘dummy’ treatment

Question 14

Define Scientific model

Answer 14

A simplified representation of a complex idea or process is called a scientific model

Once the model has been developed it can be applied for a number of situations.
Eg lock-key model for enzyme with their specific chemical protein, flowcharts, diagrams of physical models.

Question 15

What is a Variable?

Answer 15

A variable is any factor that may change during an experiment

Question 16

What is an Independent Variable

Answer 16

The independent Variable is the factor that is being investigated- the factor which is being deliberately changed to determine its effect.

It is deliberately different between the control and the experimental group in an experiment.

AKA = manipulated or experimental variable

Question 17

What is the Dependent Variable?

Answer 17

The dependent variable is the factor that changes in response to the changes made to the independent variable. It is sometimes called the responding variable.

Question 18

What is the controlled variables?

Answer 18

The controlled variables are the factors that are kept the same for both the control and the experimental groups in the experiment.

Question 19

What is the uncontrolled variable?

Answer 19

Uncontrolled variables are variables that were not kept the same for both control and experimental groups in the experiment.
The may have be overlooked by the experimenter or they may ave been impossible to control.

Question 20

Why use Graphs?

Answer 20

They are a useful way to present data so they can be understood easily.
A graphs shows how changes in one variable are affected a second variable.

Question 21

Important things to remover when drawing a graph (x4)

Answer 21

• label the axes with the names of the variables
• indicate the units in which each variable is measured
• give the graph a title that summaries the relationship illustrated by the graph
• use equal intervals on each axis

Question 22

What the three main types of graphs

Answer 22

Bar/column, Histogram and line graph

Question 23

Specifications of line graphs

Answer 23

Most commonly used

Draw dots and connect them

Question 24

Specifications of bar or column graphs

Answer 24

• represents data by rectangles l equal width, spaces between the rectangles.
• length of the rectangle represents the quantity so various quantities could be compared between each other

Question 25

Specifications of a Histogram

Answer 25

- often used to show frequencies (how often a particular value or even occurs) - equal width but no space in between the bars - used particularly when data is put into categorical groups to make them more manageable

Question 26

How make a good table

Answer 26

- Table must have a Title ; including the variables in the exp. - Data represented in columns ( usually DV in right, IV in Left) no definitive rule tho - each column has heading that names the variable and the units in which it is measured.

Question 27

Why are Placebos used in an experiment?

Answer 27

They are used in research to see the effectiveness of medical treatments, such as a new medicinal drug. A placebo is an inactive substance that looks like the real medication. - looks the same, given the same The subjects will not know who is getting the placebo (blind test) - sometimes the conductor will not know either (double blind test) to ensure there is no bias. Placebo is a dummy treatment which can come in many shapes or forms including - tablets, injection, skin patch, nasal spray, diet, physical therapy or even mock surgery.

Question 28

Explain the Placebo effect

Answer 28

Patients who are given a placebo often show an improving in their condition even though the placebo is inactive. - the placebo effect This is due to the power of the mind - thinking the therapy is real and will bring improvement.

Question 29

List the principles that an investigation must satisfy if it is to be ethically sound. (x5)

Answer 29

- 1. Voluntary Participation- no pressure from others to partake - 2. Informed consent - they should be fully informed about the objectivity of the experiment, the procedures, any risks or benefits; consent must be written and asked for after all information is given. - 3. Risk of Harm- the possibilities of harm should be minimised and the relationship between the risk and the benefit should be assessed. 4. Confidentiality- procedures need to be adopted to ensure that the identification of participants will not be revealed except to the people directly involved in the case. 5. anonymity - stronger guarantee of privacy than confidentiality; participants in study remain anonymous even to researchers. {however sometimes this may not be able to occur - instrument sizes ect.}

Question 30

Errors in Experiments

Answer 30

Results always contain errors which is why scientists rarely are definitive about their results; instead they say probably, most likely ect. Experimental error is also one of the reasons why favourable experimental results cannot prove hypothesis- they can only support

Question 31

Types of experimental error

Answer 31

Human error Systematic error Random error

Question 32

What is the purpose of designing an experiment?

Answer 32

An experiment is designed so that the results clearly support or disprove the hypothesis being tested. To support or disprove the hypothesis only one factor or variable is tested at a time. A control or comparison, experiment is done in which the only difference is in the one variable being tested. Such an experiment, involving an experimental group and an appropriate control group is known as a ‘fair test.’

Question 33

How to write a good hypothesis

Answer 33

A hypothesis is a tentative proposal made to explain certain observations. 1. Usually a definitive statement - not a question 2. Short - easier to test a simple hypothesis than a complex one 3. Has a single idea to be tested 4. Usually links two variables

Question 34

Explain scientific theories

Answer 34

Eventually if enough supporting evidence is collected and three is no evidence against the hypothesis, then it will become a theory. A scientific theory has been established and verified through investigation. It has been accepted as valid because it has been repeatedly tested.

Question 35

Religion and Science

Answer 35

Science cannot test matters of religious faith or personal Tastes Eg music

Question 36

Describe the scientific methods process

Answer 36

- Scientific Method beings with a problem 1. Recognition of the problem 2. Collection of Information related to the problem 3. Making a Hypothesis 4. Testing the Hypothesis via a suitable experiment 5. Collection of data from the experiment 6. Make a conclusion (hypothesis is supported or disproved) * with data if the hypothesis is disproved go back and make a new hypothesis or there might be new questions to answer so go back to the recognition step.

Question 37

One word scientific method steps

Answer 37

- Recognition - Collection - Hypotheis - Testing - Results - Conclusion