Chapter 1

Observation

Essential part of science, looking for patterns. When a pattern becomes evident it may be possible to draw tentative conclusions.

Controlled Experiments

Designed to investigate relationships between variables. They involve changing one variable while all the other variables are kept the same. Any difference in the results is due to the changed variable.

Surveys

A process of systematically collecting, analysing and interpreting information about an aspect of a study. Designed to collect data from a large number of subjects.

Trial and Error

Sounds random, but when used in scientific research, it is systematic. Involves one attempt to solve a problem being followed by another. 

Case studies

An in-depth investigation of one particular person or situation. Used in areas such as education and business management.

Longitudinal studies

Conducted over a long period of time. Similiar to case study, but more prolonged.

Conducting Investigations

1. Recognise problem and define a question

2. Collect as much info as possible relating to problem

3. Propose a hypothesis

4. Test hypothesis using an experiment

5. Analyse and interpret data collected from the experiment

6. Draw conclusions about whether the hypothesis was supported or disproved

7. Report on the investigation

Literature review

A survey of the material that has been written about about the subject under consideration.

Ethics

A set of moral principles or values.

1. Voluntary Participation

2. Informed consent

3. No risk of harm

4. Confidentiality

Controlling variables

Variable is any factor that may change during an experiment. 

Independent variable is the factor being investigated - changed to determine effect. 

Dependent variable is the factor that changes in response to the changes made to the independent variable. 

Controlled Variable

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

Uncontrolled variables

Variables that are not kept the same for the control and the experimental groups in an experiment. 

Validity 

The extent to which an experiment tests what it is supposed to test.

Accuracy

Refers to how close the data is to that exact value. Dependent on the equipment used.

Reliability

The extent to which an experiment gives the same result each time it is performed. The measuring instruments used must also be reliable; must give the same measurement each time they are used.

Quantitative Data

Expressed in numbers and usually involving measurement eg height.

qualitative data

Observations that do not involve human numbers or measurement. For examples student A is taller than Student B.

Secondary Data

The data that has been collected by someone other than the people who are using the data.

Percentage Change

1. Subtract old value from new value

2. Divide by the old value

3. Multiply the result by 100 and add per cent sign.