reinforcement and behaviour modification

• Continuous reinforcement

  when a behaviour is continuously reinforced eg. pay a child every time they do the washing up

  can lead to rapid change in behaviour but tends to not last
• Partial reinforcement

  Irregular - in a reinforcement schedule the ratio (of reinforcements) or interval (between reinforcements) can be varied. Either cases can be fixed or variable (ranges around a mean time)
• Partial schedules examples

  written as F (for fixed) or V (for variable) with a number indicating ratio or interval

  eg. a rat on F3 would wait 3 mins after pressing the bar before it can receive another award
• fixed ratio reinforcement schedule


  reinforcer is given a specified number of behaviours, eg pay a child every 7th time they wash dishes
• variable ratio reinforcement schedule


  reinforcer given after an unpredictable number of behaviours that vary around a mean value

  eg. child on a variable ratio of 3 (VR3) would get paid after 1, 3 or 5 instances of washing dishes ( 1 + 3 + 5 = 9/3 = 3)

  behaviour change is then difficult to stop
• Fixed interval reinforcement schedule


  time between reinforces is kept constant

  eg. paying child at end of time interval if he washed dishes 1 or more times during it
• Variable interval reinforcement schedule


  time between reinforces is varied around a mean length of time only one behaviour per time period is needed for reinforcement so a child is again paid at the end of the time period if he washes up one or more times during the interval - but this interval varies in length --> tends to result in most consistent behaviour