# Inconsistent response times

**URL:** <https://discourse.psychopy.org/t/inconsistent-response-times/13458>\
**Category:** Builder\
**Tags:** timing\
**Created:** [May 18, 2020, 3:08pm UTC](https://discourse.psychopy.org/t/inconsistent-response-times/13458 "2020-05-18T15:08:39Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![eduardugr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/eduardugr/32/8718_2.png) [@eduardugr](https://discourse.psychopy.org/u/eduardugr)\
**Post date:** [May 18, 2020, 3:08pm UTC](https://discourse.psychopy.org/t/inconsistent-response-times/13458/1 "2020-05-18T15:08:39Z")

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**OS** : Windows 10  
**PsychoPy version** : 3.2

Hi all,

I am trying to check the consistency of key press detection between .log file and .csv file using Builder.

To do so, I created a simple experiment (see picture) where I just display a letter using a Text component (to display the letters) and a Keyboard Component (to log key presses).

 ![Captura](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/6/2/629367bc6315736518c731870d5caa43dc03bc8c.png)

Then, when I run the experiment, I press a key every time a character is displayed with the intention of inspecting the ‘rt’ in the .csv file generated after the experiment is run.

I was expecting this ‘rt’ value in the .csv to be exactly the same as the response time computed from the -log file (Keypress time - autoDraw time), however this is not the case. There is always a difference between 1 to 8~9 ms, as you can check in the following image.

![Sin título](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/9/1/919fe00bb3df6af212879bc8c0bff7655dcf6190.png)

I would like to know why these two values do not match.

Thanks,  
Eduardo