This article applies to:
E-Prime 3.0
E-Prime 2.0
Detail
Timing Benchmarks
It is important to test your machine regularly because passing all timing benchmarks once does not mean the machine always passes in the future. Updates and additional software may affect the machine's timing.
Before performing any tests, refer to RELEASE INFO: Operating system (Windows 11, 10, 8.1, 8, 7, Vista, and XP) support in E-Prime [18652] to check that your current version of E-Prime and operating system are supported.
Verifying the Clock
The ClockBinTest should be performed on every machine that collects E-Prime data. Ideally, this experiment is run for at least 60 minutes. Once completed, the test informs you if the machine passes or if further review is required. Upon completion, the test lists Pass/Fail. If a failure occurs, review the suggested steps.
To manually analyze the data follow the steps below.
- Open the resulting data file (.edat2/.edat3) and Filter by "Needs Review" under "Review Status".
- If SampleRate is less than 4, the machine fails and another machine should be used. If greater than 4, continue to the next step.
- Open Bin Analysis.xlsx and follow the directions in the file.
- Look at the BIG BIN SUM%. You can use this value to determine how long to adjust your run. This is derived from columns P8 and beyond as these shows the more pronounced delays. For example, say 0.0003% is obtained on P8 and Q8 for BIN N% representing 11 and 12ms respectively over an hour run. This means that 1 time we observed an error of 11ms and 1 time we observed an error of 12ms. This gives a total of 0.0006% trials that may be inconsequential in some studies.
Verifying Display Timing
If you have access to Chronos with a Photosensor, the ChronosRefershRateAndLatencyTest can be used to quickly determine your rise and fall time as well as verify your refresh rate. The experiment should be run at the resolution and refresh rate used in your experiment. You can adjust the resolution and refresh rate in the Experiment Object Property Pages > Devices tab > Display properties. If you wish to get the general latency of your monitor, place the Photosensor in the top-left of the screen. If you wish to know the latency to your stimuli, place the Photosensor in the location your stimuli are presented.
The expected and actual refresh rate duration should be within in ms. In general, these should be close if not identical. The latency of the monitor is from the hardware itself. Knowing this delay, you may account for it in your data. If they latency is unacceptable, you need to use another monitor.
For more information, see TIMING: Why external validation of the Display is needed [25718].
If your results are not what you expect, Benchmark for Graphics and Monitors [29932] can be used to gather more detailed information about your monitor.
NOTE: In Windows 11, we have observed timing issues with experiments run on battery power. See TIMING: Running on a Windows 11 laptop may negatively impact timing [42409] for more information.
Verifying Chronos Timing
The ChronosTimingTest can be used to verify timing of Chronos as a response device. This experiment sends out an event at the OnsetTime of the Stimulus object and records when the response is registered by looping a Digital Output to a Digital Input (e.g. Digital Output 1 is wired to Digital Input 1).
For Chronos, we expect the resulting average to be less than or equal to 1ms. For more data on which to compare your Chronos and machine, see TIMING: Chronos Timing Article [24513].
If you do not have Chronos, you may use third-party hardware such as the Black Box Toolkit (BBTK) to verify your display and response device timing.
NOTE: There is no E-Prime 2.0 Standard version of this test.
See Also:
TIMING: E-Prime 2.0 Monitor Recommendations and Timing Information [18080]
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