Key words

• When the researcher makes clear at the start the sort of difference that is anticipated between 2 conditions or 2 groups of people?

  Directional hypotheses.
• When the researcher states that there is a difference between conditions or groups of people but the nature of the difference is not specified?

  Non-directional hypotheses.
• Clearly defining variables in terms of how they can be measured?

  Operationalisation.
• When an experiment compares an experimental treatment with a control treatment?

  Levels of independent variable.
• When a researcher unintentionally, or unconsciously, influences the outcome of any research they are conducting?

  Investigator effects.
• Term used to describe the identical procedure set up in an experiment?

  Standardisation.