Line and image stimuli do not show up

Online experiments
1

URL of experiment: Pavlovia

Description of the problem: hi. I am trying to build an experiment where participants make estimations on time, space and number. in each domain, participants are shown a target and they are asked to make estimations based on that target. for space domain, participants are shown a target line length for a brief duration at a random place on the screen which is then masked with a noise image for a brief duration. participants are then given an estimation line and are asked to adjust the length of this line to the target line by using “1” (to shorten) and “2” (to lengthen) buttons. however, the target line (and the noise image) sometimes does not show up at all. I also use .refresh() at the end of the routine where I draw the target line.

ps. it works fine in local.

does anybody have any idea why?

thanks in advance, tutku

2

Update: the problem was due to my random placing the line on the screen. it probably went too up or too down at times due to my bad definition of the placement limits on the screen. I’ve solved the problem by changing the upper and lower limits of the x and y axis for the stimulus placement.