Experimental Methods

• What is the definition of experimental method?


  -A scientific method which involves the manipulation of an independent variable to measure the effect of the dependent variable.
• What is the definition of the aims of a study?

  -A statement of what the researcher intends to investigate, it's the purpose of the study.

  ->Must be realistic and ethical.
• What is the definition of a hypothesis?

  -It is a clear, precise, testable statement that states the relationship between the variables being tested and predicts what the researcher expects to happen.

  ->Should be operationalised.

  ->Clearly defined and measurable, the outset of any study.
• What are the two types of hypothesis?

  -Directional hypothesis (One tailed)

  -Non-directional hypothesis (Two-tailed)
• What is the definition of a directional hypothesis?

  -Predicts that the independent variable will have an effect but also predicts the direction of this effect.

  -->Specifically states the direction of the difference or relationship.
• What is the definition of a non-directional hypothesis?

  -Doesn't state the direction or relationship of the variables.
• What does operationalisation mean?

  Defying the independent and dependent variables in such a way that they can be precisely tested and measured.

  ->Not always easy, but it is needed to give a valid measure for the variable.
• What is the definition of Independent Groups/Measures?

  An independent measures design involves using different participants in each condition.
• What is the definition of repeated measures?

  A repeated measures design involves using the same participants in each condition of an experiment.
• What is the definition of matched pairs design?

  A matched pairs design features pairs of participants matched on key particular variables.

  -->They are similar; one member is placed in the experimental group and the other in the control group.
• What are the strengths of using independent groups/measures?

  -Reduced the likelihood of demand characteristics as they only take part in one condition.

  -No order effects such as boredom/fatigue as they only take part in one condition.

  -There is better control as same materials can be used in both conditions.
• What are the limitations of using independent groups/measures?

  -Individual differences can affect the result, there is little control over pp variables and the differences can affect results. -> could be a drastic difference in pps from each condition.

  -More participants required, it takes longer, is less economical and requires more planning.
• What are the strengths of repeated measures?

  -Uses fewer participants, this saves money and time.

  -Participant variables aren't a concern.

  -Each participant acts as their own control/reduces the effect of individual differences.
• What are the limitations of repeated measures?

  -Order effects, like fatigue and boredom. This means that the order of the conditions may affect performance which reduces the internal validity.

  -Increased chance of demand characteristics, as they're taking part in both conditions they have more of a chance of guessing the aim of the experiment which might affect their behaviour.

  -Lack of control, can't use the same set of stimulus material in both conditions.
• What are the strengths of matched pairs?

  -Low order effects, only take part in one condition so don't become practiced or fatigued which improves internal validity.

  -Low demand characteristics, only take part in one condition so less likely to work out the aim.

  -Reduces effect of individual differences.

  -Can use the same set of stimulus material on both conditions
• What are the limitations of matched pairs?

  -Participant variables, eventhough attempts are maid to match the pps its not the same as using the same pps in each condition. This reduces internal validity of the research and may confound the results.

  -More participants required.