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Percent accuracy

Last updated

Percent accuracy is the number of correct responses divided by the total number of responses or items, multiplied by 100.

Topic: Measurement and data collection

In plain terms

Percent accuracy fits skills where each answer is clearly right or wrong: math problems, spelling words, comprehension questions or sound productions. It is easy to understand, but it hides speed and depends on how many items there are. Eight of ten is 80%; so is 4 of 5, which is far less reliable as evidence.

How it shows up in an IEP

Accuracy goals should state the number of items and the difficulty: "80% accuracy on 10 two-step problems at a fourth-grade level." Very short probes make each mistake change the score a lot, so use enough items for a fair sample.

Example

A student answers 14 of 20 inferential questions correctly on a probe, which is 70%. The baseline across three probes was 50%, and the goal is 80%.

Not the same as Percentile rank

Percent accuracy counts how many answers were right. A percentile compares a student's score with other students. Read the definition of Percentile rank.

Related terms

  • CriterionThe criterion in an IEP goal is the level of performance that counts as success, such as 80% accuracy, 60 words per minute, or 4 of 5 opportunities.
  • ProbeA probe is a brief check of a skill, given without teaching or help, to see what the student can do independently at that moment.
  • Trial-by-trial dataTrial-by-trial data records the student's response on every teaching trial in a session, usually as correct, incorrect or prompted.
  • Opportunity-based dataOpportunity-based data records whether a student used a skill each time a natural chance to use it came up, reported as a fraction or percent.
  • Work sample (permanent product)A work sample is a lasting product of a student's work, such as a writing piece or completed worksheet, that can be scored after the task is done.

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