AO3: Johnson and Scott

• High internal validity

  P: Johnson & Scott’s study is high in internal validity.

  E: This is because there is a cause and effect relationship in this study that cannot be explained by other factors or variables. Investigating the effects of anxiety and the weapon focus effect on eyewitness accounts.

  E: It was conducted in a laboratory experiment which means there was high control over the variables including extraneous variables.

  L: This shows that the weapon focus effect does suggest that high levels of anxiety has a negative impact on eye-witness accounts.
• Ethical Issues

  P: The study has been criticised for being unethical.

  E: The participants may have suffered from psychological harm. In this study, the researchers had purposefully created trauma inducing conditions such as the presence of a knife with blood making participants believe that a murder has taken place.

  E: Protection from harm, deception

  L: However, this supports the main conclusion of the study and the fact that the weapon focus effect is in support showing that high levels of anxiety do in fact have a negative impact on eye-witness accounts.