research methods

• what is the experimental method ?

  involves the manipulation of an independent variable to measure the effect on the dependant variable. can be lab, field, natural or quasi experiments.
• what is an aim ?

  a general statement of what the researcher intends to investigate, the purpose of the study.
• what is a hypothesis ?

  a clear, precise, testable statement that states the relationship between the variables being investigated. it is stated at the outset of any study.
• what are the types of hypothesises ?

  directional hypothesis and non directional hypothesis.
• what is a directional hypothesis ?

  states the direction of the difference or relationship. usually includes words like: more or less, higher or lower, faster or slower etc.
• what is a non directional hypothesis ?

  does not state the direction of the difference or relationship.
• what is a variable ?

  any ‘thing’ that can vary or change within an investigation. generally used in experiments to determine if changes in one thing result in changes to another.
• what is an independent variable (IV) ?

  aspect of the experimental situation that is manipulated by the researcher, or changes naturally, so the effect on the DV can be measured.
• what is a dependant variable (DV) ?

  the variable that is measured by the researcher. any effect on the DV should be caused by the change in the IV.
• what is operationalisation ?

  clearly defining variables in terms of how they can be measured. (eg kg, words, cm, happiness levels etc).
• when would you use a directional hypothesis ?

  when a theory or the findings of previous research studies suggest a particular outcome.
• when would you use a non directional hypothesis ?

  when there is no theory or previous research, or findings from earlier studies are contradictory.
• what are the 6 research issues?

  extraneous variables, confounding variables, demand characteristics, investigator effects, randomisation, standardisation.
• what are extraneous variables?

  any variable, other than the IV, that may affect the DV if it is not controlled. Extraneous variables are essentially nuisance variables that do not vary systematically with the IV.
• what are confounding variables?

  a kind of extraneous variable but the key feature is that a confounding variable varies systematically with the IV. therefore we can’t tell if any change in the DV is due to the IV or the confounding variable.
• what are demand characteristics?

  any cue from the researcher or research situation that may be interpreted by participants as revealing the purpose of an investigation. this may lead to a participant changing there behaviour within the research situation.
• what are investigator effects?

  any effect of the investigators behaviour (conscious or unconscious) on the research outcome (DV). this may include everything from the design of the study to the selection of, and interaction with, participants during the research process.
• what is randomisation?

  the use of chance methods to control for the effects of bias when designing materials and deciding the order of experimental conditions.
• what is standardisation?

  using exactly the same formalised procedures and instructions for all participants in a research study.
• what are the experimental designs?

  independent groups design (unrelated), repeated measures design and matched pairs design (related).
• what are the types of experiments?

  laboratory experiments, field experiments, natural experiments, quasi-experiments.
• what is an experimental design?

  the different ways in which participants can be organised in relation to the experimental condition.
• what is an independent groups design?

  participants are allocated to different groups where each group represents one experimental condition.
• what is a repeated measures design?

  all participants take part in all conditions of the experiment.
• what is a matched pairs design?

  pairs of participants are first matched on some variable(s) that may affect the dependant variable. then one member of the pair is assigned to condition A and the other to condition B.
• what are the strengths of an independent groups design?

  + order effects are not a problem

  + participants are less likely to guess the aim (demand characteristics)
• what are the issues with a repeated measures design?

  • there may be order effects, as repeating 2 tasks could create boredom or fatigue causing performance in second task to differ in comparison to the first task.
  • demand characteristics could impact the study as participants are more likely to figure out the aim.
• what are the issues with a independent groups design?

  • confounding variables may effect validity of results.
  • less economical as more participants are needed to collect valid data increasing the time and money spent.
• what are the strengths of a repeated measures design?

  + participant variables are controlled (higher validity).

  + less participants are needed, and less time and money spent.
• what are the issues with a matched pairs design?

  • participants can never be matched exactly
  • time consuming and expensive as pretests are often required (less economical)
• what are the strengths of a matched pairs design?

  + participants only take part in a single condition so order effects aren’t a problem.

  + demand characteristics aren’t a problem as participants only take part in a single condition.
• what is a laboratory experiment?

  an experiment that takes place in a controlled environment, where the researcher can manipulate the IV and record the effect on the DV, whist maintaining strict control of extraneous variables.
• what are the strengths of laboratory experiments?

  + high control over confounding variables and extraneous variables.

  + high internal validity so more certain about demonstrating cause and effect.

  + replication is easier because of the high level of control.
• what are the limitations of a laboratory experiment?

  • lack generalisability, as it is an unusual setting for participants so they may act differently to how they would in a familiar setting.
  • low external validity
  • demand characteristics due to usual setting
  • lacks mundane realism as it isn’t an everyday task or in a familiar setting.
• what is a field experiment?

  an experiment that takes place in a natural setting within which the researcher manipulates the IV and records the effect on the DV.
• what are the strengths of a field experiment?

  + higher mundane realism as environment is more natural.

  + high external validity as participants may be unaware they are being studied and produce more authentic and valid behaviours.
• what are the limitations of a field experimen?

  • less control over extraneous and confounding variables.
  • not as easy to replicate precisely.
  • ethical issues if participants are unaware they are being studied as they can’t consent.
• what is a natural experiment?

  an experiment where the change in the IV is not brought about by the researcher but would have happened even without the researcher being there. the researcher records the effect on the DV they decided on.
• what are the strengths of a natural experiment?

  + high external validity.

  + real world application.

  + provides research opportunities e.g Rutter et al - Romanian orphans.
• what are the limitations of a natural experiment?

  • limited opportunities for research.
  • lacks generalisability.
  • less controlled.
  • may lack mundane realism and have demand characteristics if conducted in a lab setting.