Chapter 11

• Across-subjects counterbalancing


  A technique for controlling progressive error that pools all subjects’ data together to equalize the effects of progressive error for each condition.
• Balanced Latin square

  • A partial counterbalancing technique for constructing a matrix, or square, of sequences in which each treatment condition.
  • (1) appears only once in each position in a sequence and
  • (2) precedes and follows every other condition an equal number of times.
• Block randomization

  • A process of randomization that first creates treatment blocks containing one random order of the conditions in the experiment.
  • Subjects are then assigned to fill each successive treatment block.
• Carryover effects


  The persistence of the effect of a treatment condition after the condition ends.
• Complete counterbalancing


  A technique for controlling progressive error using all possible sequences that can be formed out of the treatment conditions and using each sequence the same number of times.
• Counterbalancing

  • A technique for controlling order effects by distributing progressive error across the different treatment conditions of the experiment.
  • May also control carryover effects.
• Fatigue effects


  Changes in performance caused by fatigue, boredom, or irritation.
• Latin square counterbalancing

  • A partial counterbalancing technique in which a matrix, or square, of sequences is constructed so that each treatment appears only once in any order position.
• Mixed design


  A factorial design that combines within-subjects and between-subjects factors.
• Order effects


  Change in subjects’ performance that occurs when a condition falls in different positions in a sequence of treatments.
• Partial counterbalancing


  A technique for controlling progressive error by using some subset of the available sequences of treatment conditions.
• Power


  The chance of detecting a genuine effect of the independent variable.
• Practice effect


  Change in subjects’ performance resulting from practice.
• Progressive error

  • Changes in subjects’ responses that are caused by testing in multiple treatment conditions.
  • Includes order effects, such as the effects of practice or fatigue.
• Randomized partial counterbalancing


  The simplest partial counterbalancing procedure in which the experimenter randomly selects as many sequences of treatment conditions as there are subjects for the experiment.
• Reverse counterbalancing


  A technique for controlling progressive error for each individual subject by presenting all treatment conditions twice, first in one order, then in the reverse order.
• Subject-by-subject counterbalancing


  A technique for controlling progressive error for each individual subject by presenting all treatment conditions more than once.
• Within-subjects design

  • A design in which each subject takes part in more than one condition of the experiment.
  • Also called a repeated-measures design.
• Within-subjects factorial design


  A factorial design in which subjects receive all conditions in the experiment.