<p>A couple of studies (<a href="http://doi.acm.org/10.1145/1294211.1294231" rel="nofollow noreferrer">Harrison et al, 2007</a>; <a href="https://doi.org/10.4018/IJTHI.2016100101" rel="nofollow noreferrer">Amer &amp; Johnson, 2016</a>) tested pauses/stalls in progress, and concluded (respectively): &quot;... participants perceived progress bars with pauses as taking longer to complete ...&quot; and &quot;... participants preferred a progress bar that moves consistently to a stalling progress bar, and judged the process duration to be shorter ...&quot; suggesting that continuous/steady progress bars are preferred by users over intermittent/random indicators.</p>
<p>There is much more research on continuous progress indicators (eg, <a href="https://doi.org/10.1177%2F0894439313497468" rel="nofollow noreferrer">Villar, Callegaro, &amp; Yang, 2013</a>; <a href="https://doi.org/10.1177/0894439317695581" rel="nofollow noreferrer">Liu &amp; Wronski, 2018</a>) that suggests that users generally prefer fast-to-slow / decelerating progress - that is, inaccurate progress bars that overestimate progress early on.  Slot machines similarly use early success to increase player perseverance, a kind of <a href="https://en.wikipedia.org/wiki/Anchoring_(cognitive_bias)" rel="nofollow noreferrer">anchoring bias</a>.  However, most of this research is on progress indicators for active tasks such as filling out surveys.  Some experiments with passive waiting (like file transfers) align with their results (eg, <a href="https://www.doi.org/10.17140/PCSOJ-5-144" rel="nofollow noreferrer">Gronier &amp; Baudet, 2019</a>; <a href="https://doi.org/10.1007/978-3-319-21383-5_113" rel="nofollow noreferrer">Kuroki &amp; Ishihara, 2015</a>), but other studies show a preference for accelerating progress instead (eg, <a href="http://doi.acm.org/10.1145/1294211.1294231" rel="nofollow noreferrer">Harrison et al, 2007</a>), so I would wait for a meta-analysis specific to passive tasks before making a firm conclusion.</p>
<p>There are also various exploratory studies testing alternative progress bar displays, such as different <a href="https://doi.org/10.1109/INCoS.2011.65" rel="nofollow noreferrer">colours</a> and <a href="https://doi.org/10.1109/INCoS.2014.85" rel="nofollow noreferrer">shapes</a>, <a href="https://doi.org/10.1145/1753326.1753556" rel="nofollow noreferrer">designs</a> and <a href="https://doi.org/10.1145/2851581.2892308" rel="nofollow noreferrer">animations</a>, adding <a href="https://www.doi.org/10.14236/ewic/AD1998.9" rel="nofollow noreferrer">audio</a> and <a href="https://doi.org/10.4018/ijthi.2014070105" rel="nofollow noreferrer">video</a>, suggesting that user perceptions can be altered in a variety of novel ways.  As well, progress indicators on passive tasks may be affected by the <a href="https://doi.org/10.1109/INCoS.2014.85" rel="nofollow noreferrer">labour illusion</a>, in which user experience is influenced by the perceived amount of work done.</p>

CC BY-SA 4.0
2020-10-21T14:20:04.757Z
is this a kind of lying? What are some ethic aspect of this?
Ooker
CC BY-SA 4.0
2020-10-21T17:36:02.910Z
@Ooker You may be interested in [this article](https://www.process.st/loading-time/) - there is much worse going on with progress bars, and it's all done because users prefer it that way!
Arnon Weinberg
CC BY-SA 4.0
2020-10-21T06:55:03.700Z
2020-10-21T06:55:03.700Z
Arnon Weinberg
<p>Say we A-B tested user reactions to completing some task (e.g. transferring files, restarting their device): would people be quicker to get impatient/ annoyed if they got random percentages as indicators of progress, or if they had a steady, accurate progress bar? What if it was steady but NOT accurate?
When would people experience the most intense emotional drops or rises? Would the slot machine effect play a part, i.e. would the chance of getting a &quot;big&quot; leap (21% towards update installation!) keep users waiting patiently during the slower progress intervals?</p>
<p>This question is based off a wandering thought while my laptop was restarting recently, as well as some basic psych understanding. I can certainly see it being possible that people would, on average, be more willing to wait for a 2/3/8 min update with erratic progress than 1/2/5 mins with steady progress.
I'd be interested if anyone knows of such/similar studies and, if so, what conclusions they reached.</p>
<p>Edit: internet legend Tom Scott came through and discussed this topic recently, <a href="https://www.youtube.com/watch?v=iZnLZFRylbs" rel="nofollow noreferrer">https://www.youtube.com/watch?v=iZnLZFRylbs</a>!</p>

<perception><time>
The unpredictable loading bar -- or, the slot machine effect
themorewerealize
# The unpredictable loading bar -- or, the slot machine effect

(Asked by: username_0 on 2020-10-18)

Say we A-B tested user reactions to completing some task (e.g. transferring files, restarting their device): would people be quicker to get impatient/ annoyed if they got random percentages as indicators of progress, or if they had a steady, accurate progress bar? What if it was steady but NOT accurate?
When would people experience the most intense emotional drops or rises? Would the slot machine effect play a part, i.e. would the chance of getting a "big" leap (21% towards update installation!) keep users waiting patiently during the slower progress intervals?

This question is based off a wandering thought while my laptop was restarting recently, as well as some basic psych understanding. I can certainly see it being possible that people would, on average, be more willing to wait for a 2/3/8 min update with erratic progress than 1/2/5 mins with steady progress.
I'd be interested if anyone knows of such/similar studies and, if so, what conclusions they reached.

Edit: internet legend Tom Scott came through and discussed this topic recently, <https://www.youtube.com/watch?v=iZnLZFRylbs>!

**Tags:** perception, time


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## 1 answers

### Answer by username_1 on 2020-10-21. Score: 4 | Accepted answer

A couple of studies ([Harrison et al, 2007](http://doi.acm.org/10.1145/1294211.1294231); [Amer & Johnson, 2016](https://doi.org/10.4018/IJTHI.2016100101)) tested pauses/stalls in progress, and concluded (respectively): "... participants perceived progress bars with pauses as taking longer to complete ..." and "... participants preferred a progress bar that moves consistently to a stalling progress bar, and judged the process duration to be shorter ..." suggesting that continuous/steady progress bars are preferred by users over intermittent/random indicators.

There is much more research on continuous progress indicators (eg, [Villar, Callegaro, & Yang, 2013](https://doi.org/10.1177%2F0894439313497468); [Liu & Wronski, 2018](https://doi.org/10.1177/0894439317695581)) that suggests that users generally prefer fast-to-slow / decelerating progress - that is, inaccurate progress bars that overestimate progress early on. Slot machines similarly use early success to increase player perseverance, a kind of [anchoring bias](https://en.wikipedia.org/wiki/Anchoring_(cognitive_bias)). However, most of this research is on progress indicators for active tasks such as filling out surveys. Some experiments with passive waiting (like file transfers) align with their results (eg, [Gronier & Baudet, 2019](https://www.doi.org/10.17140/PCSOJ-5-144); [Kuroki & Ishihara, 2015](https://doi.org/10.1007/978-3-319-21383-5_113)), but other studies show a preference for accelerating progress instead (eg, [Harrison et al, 2007](http://doi.acm.org/10.1145/1294211.1294231)), so I would wait for a meta-analysis specific to passive tasks before making a firm conclusion.

There are also various exploratory studies testing alternative progress bar displays, such as different [colours](https://doi.org/10.1109/INCoS.2011.65) and [shapes](https://doi.org/10.1109/INCoS.2014.85), [designs](https://doi.org/10.1145/1753326.1753556) and [animations](https://doi.org/10.1145/2851581.2892308), adding [audio](https://www.doi.org/10.14236/ewic/AD1998.9) and [video](https://doi.org/10.4018/ijthi.2014070105), suggesting that user perceptions can be altered in a variety of novel ways. As well, progress indicators on passive tasks may be affected by the [labour illusion](https://doi.org/10.1109/INCoS.2014.85), in which user experience is influenced by the perceived amount of work done.

> **Comments:**
> **username_2**: is this a kind of lying? What are some ethic aspect of this?  
> **username_1**: @username_2 You may be interested in [this article](https://www.process.st/loading-time/) - there is much worse going on with progress bars, and it's all done because users prefer it that way!  

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