reliability and validity

• validity

  ectent to which a study measures what it is intended to measure
• internal validity

  whether the effects observed in a study are due to manipulation of the independent variable and not another factor.
• external validity

  how well you can generalise the results from research participants to people, places and times outside of the study.
• reliability

  a measure of consistency. it refers to how consistent the findings from an investigation or measuring device are. a measuring device is said to be reliable if it produces consistent results every time it is used.