Experimental Methods

• What is a directional hypothesis?


  the researcher makes clear the sort of difference they expect between the 2 conditions or 2 groups of people

  includes words: mole/less, faster/slower, higher/lower
• What is a non-directional hypothesis?

  state that there will be a difference between conditions and groups but doesn't specify the nature of difference
• When do you use non-directional hypothesis?

  when there is no previous research, or previous studies are contradictory.
• When do you use directional hypothesis?


  findings from research suggests a particular outcome
• What's an independent variable?


  the variable that is changed or manipulated by experimenter
• What's a dependant variable?


  the variable that is being measured by experimenter
• Difference between control condition and experimental condition

  control condition are those who do not receive the 'experimental condition' e.g. those not given a sweet

  experimental condition are those who receive the condition e.g. those given a sweet
• What does it mean to 'operationalise' a variable?

  ensuring all variables are measurable/defining how they can be measured
• formula for writing a directional hypothesis


  IV + DV + IV
• formula for writing a non-directional hypothesis


  TWBAD + DV + IV + IV