IRT Simulator: Items and Test
Parameters, item curves and test assembly with cut scores
Items
Item bank
Test
Item 1
Discrimination a
0.10
3.50
Location b
−6.5
6.5
Lower asymptote c
0.00
0.40
Item 2
Discrimination a
0.10
3.50
Location b
−6.5
6.5
Lower asymptote c
0.00
0.40
Cut scores
Cut 1
Cut 2
Cut 3
Visible θ scale
Symmetric range
±2
±8
The range remains symmetric around 0. If a cut score falls outside the visible scale, it is marked at the corresponding edge.
Reset items
Reset cut scores
Item characteristic curves (ICCs)
Item information functions (IIFs)
Standard error by item (SE)
When SE exceeds the visible maximum of the graph, the curve is not shown in that region to avoid an artificial line at the boundary.
Values at the cut scores
Item bank
Turn items on or off to compare their individual curves. The same selection is automatically used in the Test tab.
Item characteristic curves (ICCs)
Item information functions (IIFs)
Standard error by item (SE)
Item values at the cut scores
Test construction
Turn items on or off to observe how the test functions as a whole. The selection is synchronised with the Item Bank tab.
Test characteristic curve (TCC)
Test information function (TIF)
Standard error of the test (SE)
Test values at the cut scores