DVS

Here you can configure application settings:

This is the task of estimating the duration of visual stimuli.

A black square will appear approximately in the middle of the screen.

Your task is to estimate the display time of each black square.

The panel for entering your answer will not be visible during the display of the square, it will appear only after the delay period. Enter the estimated display time of the previous stimulus in the corresponding text box. It is necessary to enter the time in milliseconds because it is possible that some stimuli are shorter than 1 second.

You must enter a valid Estimation value before moving on to the next task.

To return to the previous task, click the "left arrow" button.

As the demo mode is on, the correct solution will be displayed in each task.

Maximize a window (page) before starting the task. You must not resize the screen during the task.

Application settings:

Frame rate is produced by a combination of your graphics card and your processor, so it is essentially the number of frames a system is able to produce in a second, whereas refresh rate is the rate at which a monitor is able to completely refresh its display.

Minimum stimulus duration (ms):

Number of steps to increase stimulus length (iteration):

In each step, increase the stimulus length by this value (ms):

Number of repetitions of the same stimuli:

The number of stimuli in the task = 5

Requested stimulus sequence: 100 200 300 400 500 Randomly mixed. Units: ms.

Delay time before show each stimulus (ms):

Delay time after show each stimulus (ms):

Maximum number of stimulus repetitions within the same item:

Enable backward - display the button for the previous item:Yes

Missing values are allowed:Missing values are allowed. The user does not have to enter a value.

Progress bar is visible:Progress bar will show the number of the current item and the number of remaining items until the end of the task.

Show solution of each task (demo):No

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Latest research

Select data:

Legend:

Variables = Combination of variables used for bivariate correlation

Spearman-ro = Spearman's rank correlation coefficient. Spearman’s formula with tied ranks was used

t-value ro = Student's t-distribution (Gosset) value argument for ro

df = Degree of freedom (Student's t-distribution)

p-ro (two-sided) = Two-tailed probability or cumulative distribution function (CDF) for t-value ro

Pearson r = Pearson correlation coefficient.

t-value r = Student's t-distribution (Gosset) value argument for r

p-r (two-sided) = Two-tailed probability or cumulative distribution function (CDF) for t-value r

NaN = If printed NaN cannot be calculated. Example if sample variance = 0 for Pearson r or Spearman-ro.

If the value in the table is not printed, it cannot be calculated.

Inferential statistics are automatically calculated for n>2 (only for valid estimates). Ignore or at least very carefully use inferential statistics for small sample size.

Sample standard deviation is calculated with Bessel's correction (n-1)

The error is calculated by the formula: 100 * |estimation - correct| / correct

Accuracy of measured (correct) times

The measured values are based on a DOMHighResTimeStamp high-precision timer that is (in theory) more accurate than 1ms (millisecond).

Limitations:

Security threats. To offer protection against timing attacks and fingerprinting, the precision of time stamps might get rounded depending on browser settings.

Frame rate. Frame rate (expressed in frames per second or FPS) is the frequency at which consecutive images (frames) are captured or displayed. More information: here. The minimum stimulus display time (as well as the value of the iteration step) is the same as the time required to refresh the screen. The higher the refresh rate of the used OS (browser), this time is less.

Real times are almost certainly higher than measured because all measured times need to be added hardware (and OS) delay time.

However, if this task is run under controlled conditions, this delay is constant within all measurements. Therefore, do not minimize the browser during the task. For the same reason, it is not allowed to resize the screen during the execution of the task.

You must not resize the screen during the task. The task is aborted. Click the Repeat button to restart the task.

Results by items:

The error and all statistics were calculated for the variables: Correct-Estimation

Descriptive statistics:

Inferential statistics - correlations:

Note: Ignore or at least very carefully use inferential statistics for small sample size. For an explanation of the terms used, see Options => Latest Research