Inter-rater and inter-rater reliability

Data set

• The data is based on a paper by Eliasziw et al., 1994.
• One therapist uses two goniometers (i.e., electro vs. manual) to measure knee joint angles three times.
• Twenty-nine subjects (n=29) were measured three consecutive times (m=3) on each goniometer (t=2) at one joint position (i.e., full passive extension)

The data can be found here.

The Challenge

Visualize the data to answer the following questions:

• Inter-goniometer: do the two goniometers agree?
• Intra-goniometer: do the goniometers measure consistently the knee joint angle across the three repeated measurements?

Reference

Eliasziw M, Young SL, Woodbury MG, Fryday-Field K. Statistical methodology for the concurrent assessment of interrater and intrarater reliability: using goniometric measurements as an example. Phys Ther. 1994 Aug;74(8):777-88. doi: 10.1093/ptj/74.8.777. PMID: 8047565.