Decreasing trend
A decreasing trend is a pattern in which graphed data points fall over time, moving downward on the y-axis across sessions.
A decreasing (or descending, downward) trend means the measured value is getting smaller over a series of sessions. On a line graph, the data path slopes down from left to right. As with any trend, it is judged from the overall direction of the data in a phase, not from two individual points.
A decreasing trend is usually the goal for problem behavior: fewer hits per hour, shorter tantrums, a lower percentage of intervals with scripting. For a skill, though, a decreasing trend is a warning sign. If percentage correct or independent responses decline, possible reasons include problems with motivation, prompt dependence, changes in the client's health or routine, or procedures not being implemented as written.
A decreasing trend in problem behavior during baseline also matters, because behavior already improving without intervention makes it hard to show that the intervention caused later change. RBTs recognize decreasing trends, document events that might explain them, and report them to the supervisor, who decides whether to continue, change or fade a procedure.
Example and non-example
| Example | After differential reinforcement begins, a client's hits per session go 14, 11, 9, 6, 4, a decreasing trend in a behavior targeted for reduction. |
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| Non-example | Data that remain at about 5 hits per session across ten sessions show a stable level with zero trend. |
Don't confuse it with
| Increasing trend | A decreasing trend slopes downward over time; an increasing trend slopes upward. |
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| Level | A decreasing trend is about direction; a low level is about where data sit, regardless of direction. |
Test yourself
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Question 1This graph shows a behavior targeted for reduction. What do the data show?
Number of tantrums by Session: 1: 12, 2: 11, 3: 9, 4: 8, 5: 6, 6: 5, 7: 3. Phases: Intervention from session 1. Show answer
C: The behavior is decreasing across sessions. The data path falls steadily, which is a decreasing trend, the desired direction for a behavior targeted for reduction.
- A: The values get lower over time, not higher.
- B: The values change steadily from session to session.
- D: The points follow a steady downward path with little bounce.
Task A.7 · 40-hour curriculum section C
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Question 2This graph shows baseline data for a behavior targeted for reduction. The supervisor plans to begin intervention next week. What should the RBT point out to the supervisor?
Number of instances of hitting by Session: 1: 10, 2: 9, 3: 7, 4: 6, 5: 4. Phases: Baseline from session 1. Show answer
B: The behavior is already decreasing in baseline. The baseline data path falls across sessions. A trend already moving in the desired direction is important information for the supervisor's decision about when to start intervention.
- A: The baseline values fall, not rise.
- C: The data are not stable; they show a clear decreasing trend.
- D: The points follow a steady downward path rather than bouncing.
Task A.7 · 40-hour curriculum section C
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Question 3This graph shows a reading skill being taught. Which describes what the data show?
Percentage of words read correctly by Session: 1: 80, 2: 70, 3: 65, 4: 55, 5: 50. Phases: Intervention from session 1. Show answer
D: A decreasing trend, opposite to the goal. Percentage correct is falling across sessions. For a skill being taught, the goal is an increase, so this trend runs the wrong way and should be reported to the supervisor.
- A: The values fall across sessions, not rise.
- B: The values change steadily, so there is a clear trend.
- C: For a skill being taught, a decrease moves away from the goal.
Task A.7 · 40-hour curriculum section C
Answer every question to see your score.
On the RBT exam
This term belongs to task A.7 Identifying trends in graphed data in content area A, Data Collection and Graphing, which is 13 of the 75 scored questions.