Ch' 15 SingleSubject Designs

1
Ch. 15 Single-Subject Designs

• When are single-subject designs or small number
  designs appropriate?
• Contrast group designs and single-subject designs
• idiographic approach vs. nomothetic approach
• 2 general research strategies
• Case-studies- describe wide range of behaviors
  do not typically involve systematic observation
  or careful measurement
• Single-subject design- is a within-subjects time
  series design quasi-experiment with one subject

2
Ch. 15 Single-Subject Designs

• 4 Key elements of Single-subject research
• 1. Choice of measurement technique- should be
  sensitive to change
• frequency how often behavior occurs
• event recording rate of occurrence
  occurrences
• 
  elapsed time
• interval recording partial, whole, time
  sampling
• duration how long behavior lasts total or
  average
• intensity estimate of the force of a behavior
  subjective, rating scales
• latency length of time elapsing between
  instructions to perform a behavior and the
  occurrence of that behavior.

3
Ch. 15 Single-Subject Designs

• Pg. 481 the Cameron Case
• 2. Design Phase in Single-subject designs
• Baseline the A phase
• Treatment phase B phase
• additional treatment phases would be labeled
  C, D, etc.
• Presentation of Data generally relies on
  visual
• inspection see graph on p. 487
• Threats to the validity of data potential
  confounds instrumentation (due to repeated
  measurements), observer drift, topographical
  drift, reactivity practice effects,
  implementation integrity, maturation, history,
  placebo effects

4
Ch. 15 Single-Subject Designs

• Specific Research Designs
• ABAB Designs
• - Involve the repeated administration and
  withdrawal of the treatment or independent
  variable. Refer to Fig. 15.2, p. 491
• Changing Conditions (ABCAC) Design
• - A variation of the ABAB design which
  introduces additional treatments. Refer to Fig.
  15.3, p. 494
• Multiple Baseline Designs
• -Applies the intervention to a series of
  dependent variables (targets) at different points
  in time. Refer to Fig. 15.4, p. 496
• Changing Criterion Design
• - Used to change an individuals behavior in
  small, gradual, attainable steps, until the final
  behavioral goal is reached (known as shaping by
  successive approximations). Refer to Fig. 15.5,
  p. 500

5
Ch. 15 Single-Subject Designs

• Alternating Treatment Designs
• - The interventions are simultaneously presented
  during the same treatment phase, rather than in
  sequential phases as in the changing conditions
  design so, 2 or more different interventions are
  administered in rotating fashion.
• Refer to Figure 15.6 on p. 503
• Mixed Designs
• - Combine elements of several different
  designs.
• Refer to Figure 15.7 on p. 506
• EVALUATION OF DATA FROM SINGLE-SUBJECT DESIGNS