RatingScale¶

class psychopy.visual.RatingScale(*args, **kwargs)[source]

A class for obtaining ratings, e.g., on a 1-to-7 or categorical scale.

A RatingScale instance is a re-usable visual object having a draw() method, with customizable appearance and response options. draw() displays the rating scale, handles the subject’s mouse or key responses, and updates the display. When the subject accepts a selection, .noResponse goes False (i.e., there is a response).

You can call the getRating() method anytime to get a rating, getRT() to get the decision time, or getHistory() to obtain the entire set of (rating, RT) pairs.

There are five main elements of a rating scale: the scale (text above the line intended to be a reminder of how to use the scale), the line (with tick marks), the marker (a moveable visual indicator on the line), the labels (text below the line that label specific points), and the accept button. The appearance and function of elements can be customized by the experimenter; it is not possible to orient a rating scale to be vertical. Multiple scales can be displayed at the same time, and continuous real-time ratings can be obtained from the history.

The Builder RatingScale component gives a restricted set of options, but also allows full control over a RatingScale via the ‘customize_everything’ field.

A RatingScale instance has no idea what else is on the screen. The experimenter has to draw the item to be rated, and handle escape to break or quit, if desired. The subject can use the mouse or keys to respond. Direction keys (left, right) will move the marker in the smallest available increment (e.g., 1/10th of a tick-mark if precision = 10).

Example 1:

A basic 7-point scale:

ratingScale = visual.RatingScale(win)
item = <statement, question, image, movie, ...>
while ratingScale.noResponse:
item.draw()
ratingScale.draw()
win.flip()
rating = ratingScale.getRating()
decisionTime = ratingScale.getRT()
choiceHistory = ratingScale.getHistory()


Example 2:

For fMRI, sometimes only a keyboard can be used. If your response box sends keys 1-4, you could specify left, right, and accept keys, and not need a mouse:

ratingScale = visual.RatingScale(
win, low=1, high=5, markerStart=4,
leftKeys='1', rightKeys = '2', acceptKeys='4')


Example 3:

Categorical ratings can be obtained using choices:

ratingScale = visual.RatingScale(
win, choices=['agree', 'disagree'],
markerStart=0.5, singleClick=True)


For other examples see Coder Demos -> stimuli -> ratingScale.py.

Authors
• 2010 Jeremy Gray: original code and on-going updates

• 2012 Henrik Singmann: tickMarks, labels, ticksAboveLine

• 2014 Jeremy Gray: multiple API changes (v1.80.00)

Parameters
win :

A Window object (required).

choices :

A list of items which the subject can choose among. choices takes precedence over low, high, precision, scale, labels, and tickMarks.

low :

Lowest numeric rating (integer), default = 1.

high :

Highest numeric rating (integer), default = 7.

precision :

Portions of a tick to accept as input [1, 10, 60, 100]; default = 1 (a whole tick). Pressing a key in leftKeys or rightKeys will move the marker by one portion of a tick. precision=60 is intended to support ratings of time-based quantities, with seconds being fractional minutes (or minutes being fractional hours). The display uses a colon (min:sec, or hours:min) to signal this to participants. The value returned by getRating() will be a proportion of a minute (e.g., 1:30 -> 1.5, or 59 seconds -> 59/60 = 0.98333). hours:min:sec is not supported.

scale :

Optional reminder message about how to respond or rate an item, displayed above the line; default = ‘<low>=not at all, <high>=extremely’. To suppress the scale, set scale=None.

labels :

Text to be placed at specific tick marks to indicate their value. Can be just the ends (if given 2 labels), ends + middle (if given 3 labels), or all points (if given the same number of labels as points).

tickMarks :

List of positions at which tick marks should be placed from low to high. The default is to space tick marks equally, one per integer value.

tickHeight :

The vertical height of tick marks: 1.0 is the default height (above line), -1.0 is below the line, and 0.0 suppresses the display of tickmarks. tickHeight is purely cosmetic, and can be fractional, e.g., 1.2.

marker :

The moveable visual indicator of the current selection. The predefined styles are ‘triangle’, ‘circle’, ‘glow’, ‘slider’, and ‘hover’. A slider moves smoothly when there are enough screen positions to move through, e.g., low=0, high=100. Hovering requires a set of choices, and allows clicking directly on individual choices; dwell-time is not recorded. Can also be set to a custom marker stimulus: any object with a .draw() method and .pos will work, e.g., visual.TextStim(win, text='[]', units='norm').

markerStart :

The location or value to be pre-selected upon initial display, either numeric or one of the choices. Can be fractional, e.g., midway between two options.

markerColor :

Color to use for a predefined marker style, e.g., ‘DarkRed’.

markerExpansion :

Only affects the glow marker: How much to expand or contract when moving rightward; 0=none, negative shrinks.

singleClick :

Enable a mouse click to both select and accept the rating, default = False. A legal key press will also count as a singleClick. The ‘accept’ box is visible, but clicking it has no effect.

postuple (x, y)

Position of the rating scale on the screen. The midpoint of the line will be positioned at (x, y); default = (0.0, -0.4) in norm units

size :

How much to expand or contract the overall rating scale display. Default size = 1.0. For larger than the default, set size > 1; for smaller, set < 1.

stretch:

Like size, but only affects the horizontal direction.

textSize :

The size of text elements, relative to the default size (i.e., a scaling factor, not points).

textColor :

Color to use for labels and scale text; default = ‘LightGray’.

textFont :

Name of the font to use; default = ‘Helvetica Bold’.

showValue :

Show the subject their current selection default = True. Ignored if singleClick is True.

showAccept :

Show the button to click to accept the current value by using the mouse; default = True.

acceptPreText :

The text to display before any value has been selected.

acceptText :

The text to display in the ‘accept’ button after a value has been selected.

acceptSize :

The width of the accept box relative to the default (e.g., 2 is twice as wide).

acceptKeys :

A list of keys that are used to accept the current response; default = ‘return’.

leftKeys :

A list of keys that each mean “move leftwards”; default = ‘left’.

rightKeys :

A list of keys that each mean “move rightwards”; default = ‘right’.

respKeys :

A list of keys to use for selecting choices, in the desired order. The first item will be the left-most choice, the second item will be the next choice, and so on.

skipKeys :

List of keys the subject can use to skip a response, default = ‘tab’. To require a response to every item, set skipKeys=None.

lineColor :

The RGB color to use for the scale line, default = ‘White’.

mouseOnly :

Require the subject to use the mouse (any keyboard input is ignored), default = False. Can be used to avoid competing with other objects for keyboard input.

noMouse:

Require the subject to use keys to respond; disable and hide the mouse. markerStart will default to the left end.

minTime :

Seconds that must elapse before a response can be accepted, default = 0.4.

maxTime :

Seconds after which a response cannot be accepted. If maxTime <= minTime, there’s no time limit. Default = 0.0 (no time limit).

disappear :

Whether the rating scale should vanish after a value is accepted. Can be useful when showing multiple scales.

flipVert :

Whether to mirror-reverse the rating scale in the vertical direction.