Key takeaways
- A baseline of at least three data points, summarized by the median, is a common starting line.
- The aim line runs from baseline to the annual target and tells you where the student should be each week.
- The four-point rule and the trend-line rule are widely used decision guides from progress-monitoring practice, not legal requirements.
- A trend that is going up can still be too slow to reach the goal; compare it with the aim line, not with zero.
- Mark instructional changes with a vertical line so the team can see what happened after each one.
A useful IEP progress graph has four parts: a baseline that shows where the student started, an aim line from that baseline to the annual target, the data points you collected, and a trend line that summarizes where the data is actually heading. The team reads the graph by comparing the data and trend with the aim line. Widely used decision rules, such as changing instruction after four consecutive points below the aim line, come from progress-monitoring practice. They help a team decide when to act, but they are guides, not law, and districts apply them differently. This guide builds a graph step by step and walks through the decisions it supports.
Set up the axes
Before any line, get the frame right.
- Horizontal axis: time, in equal steps. Use school weeks or session dates spaced evenly. If you skip a week for break, leave the gap on the graph instead of squeezing the points together, so the slope stays honest.
- Vertical axis: the goal's own unit. Percent correct for a trial goal, count per period for a frequency goal, minutes for a duration goal, percent of intervals for an interval goal. Start at zero where you can, and run it past the target.
- One goal per graph. Two goals on one graph invite comparisons between numbers that do not share a unit.
If your data is on paper, the free IEP data sheets record one line per session so each line becomes one point.
Step 1: Baseline
Baseline is the student's level before instruction on the goal starts. A common practice is at least three data points, collected under the same conditions you will use for progress checks. Summarize them with the median, the middle value, so one very good or very bad day does not set the starting line.
Baseline points of 38%, 42%, and 40% have a median of 40%. That is the number the aim line starts from.
Step 2: Aim line
The aim line connects the baseline, placed at the start date, to the annual target, placed at the goal end date. It is the path the student would follow if growth were steady. The slope tells you the expected weekly gain:
Expected weekly growth = (target minus baseline) ÷ number of weeks
For a baseline of 40%, a target of 80%, and 36 instructional weeks: (80 minus 40) ÷ 36 = about 1.1 percentage points per week. At week 12 the aim line sits at 40 + 12 × 1.1, or about 53%.
For a reduction goal, such as calling out from 12 times per period down to 3, the aim line slopes downward. Everything else in this guide works the same way with "below" and "above" swapped.
Step 3: Plot the data and mark changes
Plot each session as a point and connect points within the same phase. When the team changes instruction, draw a vertical line on the graph at that date and label it, for example "added daily 10-minute practice." Do not connect points across that line. The break is what lets the team see whether the change made a difference.
A worked graph, as a table of points
A composite third grader we will call Priya has a decoding goal: "Priya will read CVC and CVCe words with 80% accuracy." Baseline median is 40%, the target is 80% at week 36, and the team collects one 10-word probe per week.
| Week | Aim line | Priya | Above or below aim | Note |
|---|---|---|---|---|
| 1 | 41.1% | 42% | Above | |
| 2 | 42.2% | 41% | Below | |
| 3 | 43.3% | 45% | Above | |
| 4 | 44.4% | 45% | Above | |
| 5 | 45.6% | 43% | Below | 1st below in a row |
| 6 | 46.7% | 45% | Below | 2nd |
| 7 | 47.8% | 44% | Below | 3rd |
| 8 | 48.9% | 46% | Below | 4th: team meets, changes instruction |
| Phase change line: added daily 10-minute word-building practice | ||||
| 9 | 50.0% | 51% | Above | |
| 10 | 51.1% | 53% | Above | |
| 11 | 52.2% | 52% | Below | Just under |
| 12 | 53.3% | 56% | Above | 3 of 4 above since the change |
Step 4: Trend line
A trend line summarizes the direction and speed of the data. Teams commonly wait for six to eight points in a phase before drawing one, because a line through three points mostly reflects noise.
A simple hand method is the split-middle line: split the phase in half, find the median value and the middle week of each half, and draw a line through those two points.
For Priya's first eight weeks:
- First half, weeks 1 to 4: values 42, 41, 45, 45. Median 43.5, at week 2.5.
- Second half, weeks 5 to 8: values 43, 45, 44, 46. Median 44.5, at week 6.5.
- Slope: (44.5 minus 43.5) ÷ 4 weeks = 0.25 points per week.
The aim line needs about 1.1 points per week. Priya's trend was going up, but at less than a quarter of the needed rate. At that pace she would reach about 52% by week 36, not 80%. Spreadsheet programs can also fit a least-squares trend line, which uses every point; either method is fine if the team uses the same one all year.
Step 5: Apply a decision rule
Two decision guides from curriculum-based measurement practice are widely used. Districts and teams adapt them, so check whether yours has a written version.
| Rule | Look at | If below the aim line | If above the aim line | Otherwise |
|---|---|---|---|---|
| Four-point rule | The four most recent consecutive points | All four below: consider changing instruction | All four above: consider raising the goal | Keep collecting |
| Trend-line rule | The trend line slope after roughly 6 to 8 points | Trend flatter than aim line: consider changing instruction | Trend steeper than aim line: consider raising the goal | Keep collecting |
For Priya, both rules pointed the same way at week 8: four consecutive points below the aim line, and a trend at a quarter of the needed slope. The team changed instruction. After the change, three of four points sit above the aim line, so the team keeps the new plan and keeps collecting. They do not raise the goal yet, because there are not four consecutive points above.
Why "trending up" is not the same as "on track"
Priya's week 8 data is a good example. Compare her last three points (45, 44, 46, average 45) with the three before (45, 45, 43, average 44.3) and the direction is up. The Evident dashboard's trend arrow uses that kind of comparison, the average of the most recent three data points against the three before them, so on this data it would read up. That is accurate: she was improving. But the aim line shows she was improving far too slowly to reach the goal. A trend arrow answers "which direction?" The aim line answers "fast enough?" A progress report needs both.
Evident's progress percent answers a third question, "how far along?" It divides the distance the student has moved from baseline by the distance from baseline to target. At week 12, Priya's 56% is (56 minus 40) ÷ (80 minus 40) = 40% of the way to her goal, while the aim line expected about 33% by that week.
Turning the graph into a report
A graph shows the team what happened. The progress report has to say it in words. IEP progress report comment examples has wording for each progress status, built from numbers like these. For trial goals, trial-by-trial data collection covers how to pool sessions into one reporting-period figure, and from daily notes to progress report covers the rest of the write-up.
In Evident, goal data points feed the progress percent and trend shown on goal cards and in the PDF progress report, and the sample evidence packet shows what that looks like printed. When Evident drafts a progress narrative, it flags a goal with fewer than four data points as insufficient data instead of describing a trend.
Common questions
How many data points do I need for a baseline?
A common practice is at least three baseline data points collected before instruction on the goal begins, summarized with the median so one unusual day does not set the starting line. Some teams collect more when the behavior varies a lot from day to day.
What is the four-point rule in progress monitoring?
It is a decision guide from curriculum-based measurement practice. If four consecutive data points fall below the aim line, the team considers changing instruction. If four fall above it, the team considers raising the goal. Otherwise, keep collecting. Districts and teams apply it differently, so treat it as a guide rather than a requirement.
How is an aim line different from a trend line?
The aim line is the planned path from baseline to the annual target, drawn before most of the data exists. The trend line summarizes the data you actually collected. Decisions come from comparing the two.
How does Evident calculate progress toward an IEP goal?
Evident reports how far the student has moved from baseline toward the annual target as a percent: current value minus baseline, divided by target minus baseline, capped between 0 and 100. A baseline of 40, target of 80, and current value of 65 is 63% of the way. It works for reduction goals too, where the target is below the baseline.