Unit 10

• Baseline


  A form of control condition where participants behaviour is measured during a control period, before the introduction of the manipulation
• Cohort Effects


  Confounded with age in a cross-sectional study

  • A cohort is a group of people born at about the same time and exposed to the same social events
• Control Series design


  An extension of the interrupted tome series qusi-experimental design in which there is a comparison or control group
• Cross Sectional Method


  A developmental research method in which people of different ages are studied at a single point in time
• History Effects


  Outside events, not the Independent variable, influence the dependent variable and provide an alternative explanation for the results
• Instrument Decay


  A threat to internal validity in which the characteristics of the measurement instrument change over time, providing an alternative explanation for the results observed
• Interrupted time series design


  A quasi-experimental design in which a treatment is investigated by examining a series of measurements made over an extended time period, both before and after the treatment is introduced
• Longitudinal Method


  A developmental research method where the same people are observed repeatedly as they grow older
• Maturation Effects


  Threats to internal validity where any naturally occurring change within individuals that occurs over time could provide an alternative explanation for the results
• Multiple Baseline Design


  Observing behaviour before and after a manipulation under multiple circumstances
• Non Equivalent Control Group Design


  Groups of participants in the different conditions are not equivalent
• Non Equivalent Control Group Pretest-posttest Design


  Non equivalent groups are used, but a pretest allows assessment of equivalency and pretest-posttest changes
• One Group Pretest-posttest Design


  The effect of an independent variable is inferred from the pretest-posttest inferred from the pretest-posttest difference in a single group
• One Group Posttest Only Design


  Has no control group and no pretest comparison

  • poor internal validity
• Program Evaluation


  Research Designed to evaluate programs designed to produce changes pr certain outcomes in a target population
• Quasi Experimental Designs


  A study design that has many features of an experiment, but due to necessity lacks some aspects of a true experimental design
• Regression Toward The Mean


  A statistical phenomenon on which extreme scores on a variables tent to be closer to the mean when a measurement is repeated, this change can be mistakenly attributed to some manipulation or intervention. Regression to the mean is an alternative explanation for an observed change
• Reversal Design


  An attempt to increase certainty in the effect to an intervention by demonstrating that the observed effects fade once an intervention is withdrawn. In a reversal design the treatment is introduced after a baseline period and then withdrawn during a second baseline period. It may be extended by adding a second introduction of the treatment.
• Selection Differences


  Differences in the type of participants who make up each group in a between subjects experimental design
• Sequential Method


  A combination of cross sectional and longitudinal designs to study developmental research questions
• Single Case Experimental Design


  A research Design in which the effect of the independent variable is assessed using data from a single participant
• Testing Effect


  Threats to internal validity in which simply taking a pretest changes behaviour without any effect of the independent variable
• Program Theory


  Assesses weather a program is designed so that it can achieve its intended outcome