Key words Flashcards
What is an explanatory variable?
A variable you can control in an experiment (should be on the x-axis).
What is a response variable?
A variable which responds to a control variable.
What is extrapolation?
When you estimate a value that is outside the values of the given data.
What is inter-observer bias?
Occurs when one observer fails to observe or measure something in the same way as another.
Advantages of using face-to-face interviews for a questionnaire.
More detailed follow up questions are possible
More likely to get an honest response
Can explain questions
Disadvantages of face-to-face interviews
Time consuming
People may be embarrassed
May have to ask many people before someone agrees to be interviewed.
Disadvantages of postal questionnaires
Lots will be ignored
People may not answer honestly
Costs a lot
How can you improve the response rate to a postal questionnaire?
Reward or prize draw
Provide a return envelope
Use “freepost”
Offer to collect
Causal relationship
When a change in one variable causes a change in another variable.
What does mutually exclusive mean?
When two events can’t be the same, eg. picking a boy and a girl.
