Consistency in Single-Case ABAB Phase Designs: A Systematic Review.
Use CONDAP ≤ 0.5 for 'very high' and > 2 for 'very low' consistency when quantifying ABAB phase patterns.
01Research in Context
What this study did
Spiegel et al. (2023) hunted for a simple way to score how steady an ABAB graph looks. They pulled 460 published ABAB data sets and ran each through a new yardstick called CONDAP.
CONDAP counts how far each data point lands from the phase mean. A score of 0 means every dot hugs the middle line. Higher numbers mean wilder bounce.
What they found
Only 4 in 10 graphs earned a 'medium' consistency label. The rest were either super tight or all over the place.
The team then set cut-offs: CONDAP ≤ 0.5 = 'very high' steadiness, > 2 = 'very low' steadiness. These marks give BCBAs a fast ruler for graph trustworthiness.
How this fits with other research
LAller et al. (2023) are testing a reading program for the students with intellectual disability using multiple baseline graphs. Those graphs can now be checked with the same CONDAP ruler, letting one study speak the same numeric language as another.
Perez et al. (2015) used brief experimental analyses to pick reading interventions for kids with ADHD. Their quick-switch ABAB style often produces bouncy data. Applying CONDAP can tell us if the bounce is too high to trust the winner.
Hattier et al. (2011) complained that ID drug trials use 25+ different outcome measures, so meta-analysis is impossible. René’s single consistency metric could rescue single-case drug studies by giving them one shared score, turning apples and oranges into numbers you can average.
Why it matters
You can now open any ABAB graph, plug the data into the free CONDAP formula, and get a number that tells families, supervisors, or funders how clear the effect is. No more eyeball fights over 'Does it look flat to you?' If the score tops 2, gather more data or tweak the intervention before you claim victory.
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02At a glance
03Original abstract
The current article presents a systematic review of consistency in single-case ABAB phase designs. We applied the CONsistency of DAta Patterns (CONDAP) measure to a sample of 460 data sets retrieved from 119 applied studies published over the past 50 years. The main purpose was to (a) identify typical CONDAP values found in published ABAB designs and (b) develop interpretational guidelines for CONDAP to be used for future studies to assess the consistency of data patterns from similar phases. The overall distribution of CONDAP values is right-skewed with several extreme values to the right of the center of the distribution. The B-phase CONDAP values fall within a narrower range than the A-phase CONDAP values. Based on the cumulative distribution of CONDAP values, we offer the following interpretational guidelines in terms of consistency: very high, 0 ≤ CONDAP ≤ 0.5; high, 0.5 < CONDAP ≤ 1; medium, 1 < CONDAP < 1.5; low, 1.5 < CONDAP ≤ 2; very low, CONDAP > 2. We give examples of combining CONDAP benchmarks with visual analysis of single-case ABAB phase designs and conclude that the majority of data patterns (41.2%) in published ABAB phase designs is medium consistent.
Behavior modification, 2023 · doi:10.1177/0145445519853793