psychology-research methods

• Hypotheses


  Statements about the prediction of the results, that can be verified or disproved by some investigation
• Types of hypotheses


  • Null Hypotheses (H0)
  • Alternative Hypotheses (Ha or H1)
  • One-tailed (directional) hypotheses
  • Two-tailed (non-directional) hypotheses
• Null Hypotheses (H0)


  Predict that no difference will be found in the results between the conditions
• Alternative Hypotheses (Ha or H1)


  Predict that there will be a significant difference in the results between the two conditions
• One-tailed (directional) hypotheses


  State the specific direction the researcher expects the results to move in, e.g. higher, lower, more, less
• Two-tailed (non-directional) hypotheses


  State that a difference will be found between the conditions of the independent variable but does not state the direction of a difference or relationship
• All research has an alternative hypothesis (either a one-tailed or two-tailed) and a corresponding null hypothesis
• Once the research is conducted and results are found, psychologists must accept one hypothesis and reject the other
• Sampling


  The process of selecting a representative group from the population under study
• Sampling techniques


  • Volunteer sample
  • Opportunity sampling
  • Random sampling
  • Systematic sampling
  • Stratified sampling
  • Snowball sampling
  • Quota sampling
• Representative


  The extent to which a sample mirrors a researcher's target population and reflects its characteristics
• Generalisability


  The extent to which their findings can be applied to the larger population of which their sample was a part
• Independent variable


  The one the experimenter manipulates (the thing that changes between the conditions the participants are placed into)
• Dependent variable


  The thing being measured, or the results of the experiment
• Operationalization of variables


  Making them measurable/quantifiable
• Extraneous variables


  All variables which are not independent variable but could affect the results of the experiment
• Demand characteristics


  A type of extraneous variable that occurs if the participants work out the aims of the research study, they may begin to behave in a certain way
• Extraneous variables must be controlled so that they do not affect (confound) the results
• Experimental design


  How participants are allocated to each condition of the independent variable, such as a control or experimental group
• Experimental designs


  • Independent design (between-groups design)
  • Matched participants design
  • Repeated measures design (within groups)
• Counterbalancing


  The best way of preventing order effects from disrupting the findings of an experiment, and involves ensuring that each condition is equally likely to be used first and second by the participants
• Experimental methods


  • Lab Experiments
  • Field experiments
  • Natural experiments
• Case studies


  In-depth investigations of a person, group, event, or community
• Case studies provide rich qualitative data and have high levels of ecological validity. However, it is difficult to generalize from individual cases as each one has unique characteristics
• Correlation


  Means association; it is a measure of the extent to which two variables are related
• Types of correlation


  • Positive correlation
  • Negative correlation
  • Zero correlation
• Correlation does not always prove causation, as a third variable may be involved
• Interview methods


  • Structured interviews
  • Unstructured interviews
• Structured interviews


  Formal, with a fixed, predetermined set of questions put to every participant in the same order and in the same way
• Unstructured interviews


  Informal, with no set questions, and the participant can raise whatever topics they feel are relevant
• Questionnaire types


  • Open questions
  • Closed questions
• Postal questionnaires


  Offer the opportunity of getting around the problem of interview bias by reducing the personal involvement of the researcher
• Observation methods


  • Covert observation
  • Overt observation
  • Controlled
  • Natural
  • Participant
  • Non-participant
• Questionnaire Method


  Questionnaires can be thought of as a kind of written interview. They can be carried out face to face, by telephone, or post.
• Questionnaire design


  • The choice of questions is important because of the need to avoid bias or ambiguity in the questions, 'leading' the respondent or causing offense.
• Open questions


  Designed to encourage a full, meaningful answer using the subject's own knowledge and feelings. They provide insights into feelings, opinions, and understanding.
• Closed questions


  Can be answered with a simple "yes" or "no" or specific information, limiting the depth of response. They are useful for gathering specific facts or confirming details.
• Postal questionnaires


  • Offer the opportunity of getting around the problem of interview bias by reducing the personal involvement of the researcher. Its other practical advantages are that it is cheaper than face-to-face interviews and can be used to contact many respondents scattered over a wide area relatively quickly.
• Types of observation methods

  • Covert observation
  • Overt observation
  • Controlled
  • Natural
  • Participant
  • Non-participant (aka "fly on the wall")
• Covert observation


  Where the researcher doesn't tell the participants they are being observed until after the study is complete. There could be ethical problems or deception and consent with this particular observation method.