How Science Works - Key Words

Question 1

Variables

Answer 1

Independent variable – you change (x axis)
Dependent variable – you measure (y axis)
Control variable – keep the same (age, sex, ethnicity etc)

Question 2

Percentages/rates/ratio

Answer 2

• Allows a comparison between ……

- As they have different populations/starting masses/birth rates etc

Question 3

Correlation/causation

Answer 3

Say if a graph shows a positive or negative correlation

• It may show a correlation but this does not mean causation
• Could be due to another factor (give examples of other factors)
• State the points that do not fit the pattern.

Question 4

Valid results

Answer 4

• What may have affected the accuracy of their results?
  e. g. how many species, sample size, appropriate temp/conc/time, repeats, standard deviation etc
• Look for results that do not fit the pattern and quote them.

Question 5

Control

Answer 5

Experiment
To compare the results from the experiment to…
• To determine that any change in the DV is directly caused by changes to the IV

Group
• Treated the same/drug administered the same
• Give a dummy/ fake drug/saline/water etc

Variable
• Keep all the same to ensure an accurate result

-In exams, they won’t ask you to define what a control variable is, you will probably have to identify what the control is in an investigation or why it is needed