Data path
A data path is the line that connects successive data points within the same condition on a line graph.
Each session's value is plotted as a point, and a straight line joins each point to the next point in the same phase. That connected line is the data path. It is the main thing a reader looks at to judge level (where the data sit on the y-axis), trend (which way they are heading) and variability (how much they bounce). When a graph shows more than one measure, each has its own data path with a different marker or line style.
Data paths are broken at phase change lines, so the last point of baseline is not joined to the first point of intervention. They are also commonly broken when a planned session did not take place, so the graph does not suggest a value for a day with no data. A zero should be plotted only when the behavior was observed and did not occur.
For the RBT, the practical rules are to plot each point at the right session and value, connect only points in the same condition, and leave gaps where no data were collected. A mistake in the data path changes how the supervisor reads the graph and can lead to the wrong decision about the intervention.
Example and non-example
| Example | An RBT enters a client's percentage correct for sessions 1 to 5 of intervention and connects the five points into one line, starting just to the right of the phase change line. |
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| Non-example | Connecting baseline session 6 to intervention session 7 across the phase change line is an error, not a correct data path. |
Don't confuse it with
| Line graph | The line graph is the whole display including axes and labels; the data path is the connected line of points within one condition. |
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| Trend | The data path is the line drawn on the graph; trend is the direction that line shows over time. |
Test yourself
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Question 1The supervisor has started intervention, and an RBT is plotting the first intervention session on a graph that shows baseline data. How should this new data point relate to the last baseline point?
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D: It is not connected; a phase change line separates them. Data points are connected only within the same condition. The data path stops at the phase change line and a new data path begins in the intervention phase.
- A: Connecting across a phase change line would blend two conditions into one data path.
- B: No line of any kind joins data paths across a phase change; the only line there is the vertical phase change line.
- C: Baseline data stay on the graph; the new session is added as its own point.
Task A.4 · 40-hour curriculum section C
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Question 2A graph shows two target behaviors, hitting and spitting, across the same sessions. What allows a reader to tell the two data paths apart?
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D: A different marker for each behavior, labeled or in a legend. When more than one data path appears on a graph, each uses its own marker (and often line style) and is labeled so readers know which behavior each path shows.
- A: Phase change lines mark changes in conditions; they do not identify which data path is which.
- B: Both behaviors share the same sessions, so they share one horizontal axis.
- C: Connecting two different behaviors would mix their data into one misleading path.
Task A.4 · 40-hour curriculum section C
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Question 3The intervention phase on this graph is ongoing. In today's session, the next session in the series, the client hit 2 times. How should the RBT add this to the graph?
Number of hits by Session: 1: 6, 2: 7, 3: 5, 4: 6, 5: 3, 6: 2, 7: 2, 8: 1. Phases: Baseline from session 1, Intervention from session 5. Show answer
D: Plot it at the next session at 2, connected to the previous point. The new session goes at the next position on the horizontal axis and at its value on the vertical axis, connected to the previous point because it is in the same condition.
- A: Data paths connect points only within the same condition, never across the phase change line.
- B: No condition changed, so no phase change line is added.
- C: Each session gets its own data point; values are not added together on a session-by-session graph.
Task A.4 · 40-hour curriculum section C
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On the RBT exam
This term belongs to task A.4 Entering data and updating graphs in content area A, Data Collection and Graphing, which is 13 of the 75 scored questions.