Experimental designs

• What is a laboratory experiment Defined by?

  The high level of control the researcher has over all the variables in the study
• What will the experimenter control in a lab experiment?

  Environmental factors and the experience the participants will have, using a standardised procedure
• What is an advantage of using a lab experiment?

  Able to control all the variables meaning the researcher can be confident in establishing a cause and effect relationship
• What’s another strength of lab experiments?

  Easily replicated due to the standardised procedures
• Do lab experiments have high or low internal validity?

  High
• What’s a limitation of lab experiments?

  If the participants are aware of the study they may change their behaviour (demand characteristics)
• what validities does lab experiments lack?

  Ecological and external
• What’s another limitation of research methods?

  Lacks mundane realism as it doesn’t reflect on tasks performed in the real-world
• What is a field experiment defined by?

  Conducting an experiment in naturalistic settings, the change in location is an attempt to avoid the artificial nature of lab studies
• What’s a strength of field experiments?

  Participants should behave more naturally in their normal environment, increasing ecological validity
• Another strength of field studies?

  More likely to have mundane realism
• Another strength of field experiments?

  If participants are unaware they’re involved in an experiment they will not show demand characteristics
• What’s a limitation of field studies?

  Limited control over variables. Such as possible extraneous variables that can influence dependent variables
• What’s another limitation of field experiments?

  Difficult or impossible to randomly assign ppts to separate conditions which can change the DV due to participant variables which reduces internal validity
• What’s a natural experiment?

  the two levels of independent variables have (or will) occured naturally (in the real world) without the influence of the researcher, they simply record the change in the DV between the two levels of the IV
• What’s a strength of natural experiments?

  Allows research in areas that could not happen in controlled experimentation, either due to ethical or cost reasons
• What’s another strength of natural experiments?

  High in external validity as they’re an example of real behaviour in the real world free of demand characteristics
• What’s a limitation of natural experiments?

  Limited control And no influence, this means extraneous variables can’t be controlled and the researcher shouldn’t claim they have found a cause and effect relationship
• Another limitation of natural experiments?

  Often very rare events that can’t be replicated exactly in order for reliability
• What’s a quasi experiment?

  A quasi experiment is a research design that lacks random assignment of participants to groups. The IV has not been determined by anyone.
• What’s a strength of quasi experiments?

  The only way to experimentally study factors that are pre-existing characteristics of participants
• What’s a limitation of quasi experiments?

  Confounding variables. May be other factors related to the level of IV that cannot be controlled as they may alter the measurement of the DV