Skip to main content
Figure 2 | Health and Quality of Life Outcomes

Figure 2

From: Measurement precision of the disability for back pain scale-by applying Rasch analysis

Figure 2

The response category probability curve for a five-step item. (A) An example of a well-functioning category response (item 4), showing a monotonic increase of the thresholds (δ) in the order of the logits level. (B) An example of a poorly-functioning category response (item 6), showing a disordering of the thresholds, and with the ordering of the δ i 2 (categories between 2 and 3) and δ i 3 (categories between 3 and 4) reversed.

Back to article page