Graph window

Button or Slider

Function

Graph Box

Title

Item entry number and label, or depends on type of graph

y-axis label and units

depends on type of graph

x-axis label

"Measure", person measures

"Measure relative to item difficulty", (person measures - item difficulty)

To switch from "Measure" to "Measure relative to item difficulty", click the blue button "Relative x-axis"

To switch from "Measure relative to item difficulty" to "Measure", click the blue button "Absolute x-axis"

x-axis units

logits or user-scaled units

legend below x-axis label

displayed when blue "Display Legend" button is clicked

curve label

click once on curve

hide curve

double-click on curve. If all curves are hidden, then they are all re-displayed.

Right-hand side:

Adjust maximum Y-value

Sets the maximum value on the vertical Y-axis

Copy Plot to Clipboard

Copies the graph to the Windows clipboard. This only copies the part of the plot that is visible on your screen. Maximize the chart window and increase your screen resolution if the entire plot is not visible. To increase screen resolution: Windows "Start", "Settings", "Control Panel", "Display", "Settings" and move the "Screen resolution" slider to the right.

Open a graphics or word-processing program, such as Paint or Word, and paste in the image for editing. To save the graphics plot in black-and-white, "Save As", "Black-and-white".

Copying many similar graphs can be expedited with a keyboard macro, such as autohotkey: www.autohotkey.com

Copy Data to Clipboard

Copies the graphed numbers to the Windows clipboard (for pasting into Excel, etc.) Use paste special to paste as a picture meta-file, bitmap or as a text listing of the data points.

Each row corresponds to a set of points to plot:

Column A - ignore (internal row identifier)

Column B - x-axis for point on first curve: measure relative to item difficulty or relative to latent variable

Column C - y-axis for point on first curve: probability, expected score, etc.

Column D - x-axis for point on second curve: measure relative to item difficulty or relative to latent variable

Column E - y-axis for point on second curve: probability, expected score, etc.

etc.

Scatterplot:

Column C (y-axis) against Column B (x-axis)

Column E (y-axis) against Column D (x-axis)

etc.

Combined plots: the curves on two or more Winsteps graphs can be combined into one Excel plot using "Copy Data" from the different graphs into one Excel worksheet.

Next Curve

Displays the same graph for the item with the next higher entry number.

Select Curves

Displays the graph for the selected item from the curve-selection-box:

Previous Curve

Displays the same graph for the item with the next lower entry number.

Probability Cat. Curves

Displays the Rasch-model probability-curve for each response-category

Non-Uniform DIF

Displays the Rasch-model curve for the item and the empirical DIF curves for the DIF classifications groups when "Non-uniform DIF" is clicked on the Graphs Menu,

Prob+Empirical Cat. Curves

Displays the Rasch-model probability-curve for each response-category, together with the empirical curve summarizing the data in each empirical interval.

Empirical Cat. Curves

Displays the empirical curve for each response-category, summarizing the data in each empirical interval

Prob+Empirical Option Curves

Displays the Rasch-model probability-curve for each response-option, together with the empirical curve summarizing the data in each empirical interval.

Empirical Option-Curves

Displays the empirical curve for each response-option, summarizing the data in each empirical interval

Expected Score ICC

Displays the expected-score item characteristic curve, the item's Rasch-model logistic ogive.

Empirical Randomness

Displays the fit of the item,  summarizing the data in each empirical interval

Exp+Empirical ICC

Displays the expected-score item characteristic curve, the item's Rasch-model logistic ogive, together with the empirical ICC summarizing the data in each empirical interval.

Empirical ICC

Displays the item's empirical item characteristic curve, summarizing the data in each empirical interval.

Cumulative Probabilities

Displays the Rasch-model cumulative probability-curve for each response-category and the categories below it.

Conditional Probabilities

Displays the Rasch-model probability-curve for the relative probability of each adjacent pair of categories. These are dichotomous ogives.

Item Information

Displays the item-information function according to the Rasch model.

Category Information

Displays the information function for each category according to the Rasch model.

Multiple Item ICCs

Displays multiple Rasch-model and empirical item characteristic curves as selected in the ICC-selection box.

Test Randomness

Displays the fit of all the items in the test,  summarizing the data in each empirical interval

Test CC

Displays the Rasch-model test characteristic curve (TCC), showing the relationship between raw scores and Rasch measures on the complete test of all active items.

Test Information

Displays the Test-Information Function (TIF) according to the Rasch model. The inverse square-root of the test information is the standard error of the Rasch person measure.

Click on line for description

Click on a curve to show its description below the graph. You can identify an individual traceline by single-left-clicking on it. Its description will then appear below the plot. Click elsewhere on the plot to remove the selection indicators.

Double-click to erase line

You can remove a traceline by double-left-clicking on it. Click on the command button, e.g., "Probability Curves", to return the plot to its initial appearance.

Display Legend

Hide Legend

Click on "Display legend" to show descriptions of all the curves below the graph.

Click on "Hide legend" to remove the descriptions.

Absolute x-axis

Relative x-axis

Click on "Absolute x-axis" to show the graphs with measures on the latent variable along the x-axis.

Click on "Relative x-axis" to show the graphs with the x-axis plotted relative to the item difficulty.

Multiple Item ICCs shows what happens for these two choices

Flip Curves Vertically

Reverses the cumulative probability curves on the y-axis

Points, Lines, None, Both

Click on this button to show the empirical curves as both points("x") and lines, points only, lines only, and neither points nor lines.

Adjust minimum Y-value

Sets the minimum value on the vertical Y-axis

Smoothing

Controls the degrees of smoothing of the empirical curve

Set Color

Click on a curve to select it, the click on "Set Color" to change its color using the color-selection-box. White makes the line disappear.

Help

Click on Help to display this page.

Across the bottom: left to right

Adjust Y-axis divisions

Sets the number of tick-marks on the Y-axis

Adjust minimum X-value

Sets the minimum value on the horizontal X-axis. To decrease the minimum possible X-value, set EXTREMESCORE= to a small value.

Adjust X-axis divisions

Sets the number of tick-marks on the X-axis

Empirical interval

Sets the number of empirical summary-intervals on the X-axis. Each observation, Xni, has an observed (empirical) value, such as 0 or 1 for a dichotomy, and also a measure on the rating scale = Ability of person n - Difficulty of item i.

These observations are summarized into empirical intervals on the latent variable. Each summary is plotted as the mean of the observed values in the interval (y-axis) and the mean of the measures (x-axis). The maximum size of the interval is from the lowest measure for any observation to the highest measure for an observation. The minimum size of the interval is .01 logits. The difference between the maximum size and the minimum size is divided into roughly 100 increments. Using the empirical interval slider, or left-right arrows, changes the size of the interval. The current size of the interval is shown in "Empirical x.xx Interval" The 1-200 number of the empirical slider is a rough indicator of relative size, and can be ignored.

Adjust maximum X-value

Sets the maximum value on the horizontal X-axis. To increase the maximum possible X-value, set EXTREMESCORE= to a small value.

Curve selection Box

ICC Selection Box

Color Selection Box