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Sept. 1, 2016

Human Factors Cast E007 - Displays (Part 1)

This week on the show, Nick and Billy go over som…

This week on the show, Nick and Billy go over some of the intricacies of displays.

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| Disclaimer: Transcript provided by YouTube automatic Closed Caption. Any inaccuracies or errors are not attributed to the Hosts or contributors to Human Factors Cast. |

this episode of human factors cast is brought to you by audible go to audible let them know that Nick and Billy sent you go to

so yeah the best part is that you get a free book every month and the book is yours you get to keep it if you don't like the book audibles great they'll just go ahead and switch it out for you so go ahead visit them again at audible trial common factors cast today on the show Billy and I are talking about design so let's get started

welcome to human factors cast your weekly podcast for all things human factors psychology and design here are your hosts NIC Rome and Billy Hall

hello and welcome back to another episode of human factors cast my name is Nick Rome human factors practitioner and as always I'm joined here by mr. Billy Oh oh you say that with such loving and care it's so great deadly we Haiti I had to act for them for the microphone Billy how are you I'm doing great how about you man I'm good I'm really good yeah no this topic today looks pretty pretty tasty great pretty needy there's a lot of meat to this topic yeah yeah it seemed like a simple topic but when I really started diving into what you gave me it seemed really neat and meaty and good what are we talking about we're talking about displays today at first you were all like displays that's that's boring I thought we were gonna be talking about look at how all these buttons are laid out and I realized there was more to it well yeah there's a ton more to it yeah you know I I didn't know this hey I have some exciting news mmm there may be some opportunity for some sponsorship in the future really what kind I'm not at liberty to say Oh stay tuned your next episode might open with one but we'll see we'll see no I really I thought you were talking about the new IV calculator on pokémons oh no wow that's pretty cool I like it I've been using it yeah so funny pictures about it but anyway this is a family show so anyway displays yeah what do you what do you think a display is like what is your concept of a display well I like I said I thought it was the idea of like button layouts you know how everything looks and then setup pushing this mat that's what I thought it was the whole time okay all right that's why I didn't think it was going to be that meaty of a topic okay that's okay yeah that's that's good that's good so I guess you know what what a display is all right I guess we should define it right like a prom so everyone everyone's on the same page here what a display is is some sort of output right for some sort of information mmm okay so that's that's it at its basic level right an output for information right so this could be a visual display a tactile display like your remote control like a TV remote could be a display on how it's like laid out kind of yeah there I'm thinking of something else when I think of tactile and it's really cool displays today but I will cover it briefly so all right okay tuned and then yeah so I mean it's yeah again just basically some sort of way to present present information and and this could be an out output device right there and typically what you're used to is like your monitor right that's that's a pretty pretty ubiquitous display uh-huh right and and pretty well known but there are also other types of displays okay what are the different types of plays well so well like I mentioned earlier there's there's the visual displays uh-huh and then there's also haptic and there's auditory as well our dick yeah so those are like like force feedback right so or tactile displays those are kind of what we just talked about right with you you were saying like like your remote could be a display and yes a remote could be a display mm-hmm if it has Braille Oh kind of like how you always see those keyboards that always like that are for blind people in the movies they have little buttons that pop up and things like that yeah so a haptic or or or a tactile display is basically something that you know displays information tak-tek highly tech would it display actively I don't know it divides and conquers the situation don't email me I looked it up later

well anyway the idea is that it presents information through the through the touch through touch right so that's that's really cool that's really cool and and you know they've played around with displays like so your tongue is the most sensitive part on your body that's like easily accessible let's let's get that straight this is a family show don't give me that so anyway the tongue is one of the most easily accessible sort of sensitive areas of your body and so they made this display this haptic display that you put on your tongue and you can feel two different points and you know like if it activates this region you know I mean something and if it means it activates the other side it means something else and the tip of the tongue it means something else so you know in an instance where you're going to be using your hands for something like controlling or operating a large vehicle huh you know this display could give you some sort of heads-up about like any anything really well gives feedback they used to talk about the idea that people would use that kind of display for like going into sci-fi stuff like that they a lot of people seem to be able to use that display in power armor students you know because you can't type away the keyboard and not everything can be auditory and you are using your hands to motion the arms so the idea of it was is that they be able to use mouth the tongue the auditory of the eyes the ears everything to tell you information yeah exactly yeah you got it and so so yeah with let's there's also auditory when you mention auditory in this science fictiony robot suit don't get mad at me I know it's a mech I'm just no it's not actually a robot suit a robot suit I was thinking about was uh no mechs you have a cockpit no I was thinking about the like EXO suits EXO suits or Ironman type suits or or a glitter boy from riffs that's right deep cut of nerd history all right all right so anyway there's there's these auditory displays and I actually worked on a cool project where we were looking at kind of so what can you talk about this yeah yes I can yeah I know I'm actually talking about something this this wasn't for the US military is gonna come right through this door right now this wasn't for the US military's conduct but this was actually directed at blind individuals okay that's cool yeah so so this was directed at blind individuals and they basically so with auditory displays as it is now think of think of an auditory display of something like like a voice reader for like like a web page right you go to a web page and you have this reader that reads every word on the page uh-huh and the primary problem with this is that the information is presented to you serially one word after the other yeah okay cat ran fast right I mean they listen to it at a million were a million words per second so the camera nest right the Cameron cast on the street and then you jumped up a hill and climbed in a tree like that very active cat like somebody's probably listening to our podcast at two times the speed really you can do that mm-hmm I've tried it I do that with some podcasts if it's you no longer podcast and I want to get through it uh-huh but anyway so so yeah the problem is that they listen to these things serially Oh one at a time and so what we were looking at is how can we display this information in a way that they can get sort of an overview of the page mm-hmm all at once right cuz because when you use your visual system to look at a webpage you don't get it like top left corner to top right corner next line left to right next lion left to right you glanced at it and you can see all this information on the page at your whim you can look at it and oh I see what you're saying so if I looked at a page I don't know with a bunch of pictures on it I can see the pictures I get in I get information based on the pictures I can see ads on the side of it nah yeah I can see pop-up quotes and little sources and brackets and I can see I can gain a lot of information before I even write read the article about what's going on exactly that's how they get you with the clickbait - yes and no click made something completely different but let's let's focus on all right it's not an auditory display so you want to do an episode on clickbait okay yes yeah writing good enough to do that one-click baked I love clickbait like I'm always like oh you got me I'm invested now clickbait episode question mark okay it's in my notes alright okay auditory display aha these people these these visually impaired individuals uh-huh they can't they again they get it serially they can't see literally they cannot experience a webpage or digital content in the same way that you or I can mm-hmm right they we have the benefit of looking down a page and reading the first couple lines and then skimming and then reading a couple more lines and skimming some more uh-huh they have to listen to it all one word after the other okay I'm annoying yeah so anyway this project that I was working on we we kind of looked into how exactly we can sort of provide through you know the auditory sense how you can get that sort of display of information and what we came up with were these virtual soundscapes which instead of we talked about virtual worlds what two podcasts ago yep about that instead of these virtual worlds we we had sort of like imagined sounds in spatial locations out in front of you right so instead of having you know instead of listening serially home about contact you know menu items or whatever what happen now you hear home about contact all simultaneously coming at you from different directions repeating and you know what you're looking for you can kind of tune in to that and go ah it's over to my left point left click and then you're there okay so like the idea of a menu if you had go left I mean like if you had a menu like home contacts you know about articles mouton video daddy you would actually it could actually see your spatial awareness like I'm looking around yeah and I kind of went to cut one of my eyes kind of glanced over it it kind of grabbed nidal by the tab even not even that like they're just hearing this all the time so like imagine my voice over here is saying sports sports sports aha ports and then from the other side of you it says technology technology technology and they're happening at the same time so you hear like a Miss mix mosh of sports technologies mortality sport ology yeah and the more I go over to one will it focus on them or other that's something that we didn't play around with but I mean it might be the idea of like it might be the idea that I just ain't blind on me we'll see here's the thing so the idea is that if you know what you're looking for you can find it quicker right if you know you're looking for technology you're gonna be listening for this thing anyway I just thought it was a cool project no that's a cool project anyway so so we're talking about the different types right so we talked about haptic we talked about auditory last which is the most common type of display is the visual display right right what you use your eyes for and so we uh you know we have to there's 2d displays uh-huh right and this is something that a lot of people are familiar with there's a there's a ton of different technologies that can be used like a LCD LED LED all this thing I'm not going to get into that that's way too technical okay for this pot anyway so the the the idea here is that you know these these different types right the things that I just described those might affect how you design your display hmm and you might be asking how Wow yeah no no I'm like affect you differently to say I thought you were continuing on the sentence no definitely how does it do it well so so one way would be and this is just for example like you have the old CRT displays right and those are very limited in resolution right um and you know believe it or not CRTs are still used in some applications such as like electrical relay substations or that's that's the off the side of the road where you see these yeah yeah yeah transformers and everything inside the displays can be CRT so when you're going through and you're designing software or some sort of display for you know the application these are things that you have to keep in mind that the pixel size is a little bit larger on those screens so you can't make something that's super high resolution to where you need to distinguish between two things that are close together so sometimes even in design I mean like you always talk about the idea of a limitation of technology yeah exactly and that would be one of them okay so you have to think about that limitation of technology when you're designing so exactly not to mention that I would imagine a CRT is a lot tougher than the average LCD or other type of displays I don't know I'm not all weather all terrain you know type of thing maybe hmm maybe yeah and then so lastly there's there's a something that I'm very fond of yeah 3d displays and these are cool because it's not just head-mounted displays that's what everybody thinks right but actually when I think about it I think about like those you know you see those computer screens that people are always like tapping on air to bring it up there or picking it up and looking at and then throwing it away like Minority Report right yeah yeah yeah you know you know what the problem with those displays are well it's more a problem with the controls rather because pressure no it's it's actually the fact that you know there's nothing to put your hands against so when you're interacting with this well I want all of our listeners and you to hold your hands out in front of you for about 20 seconds uh-huh and tell me that you can imagine doing this all day oh yeah with no feedback no desk to rest it on and just now start moving them around like you're like you're doing something right mad we would have like ripped muscles we would but it's really tiring that's an ergonomics issue and we should talk about ergonomics and anthropometry in another what you call me so so yeah there's 3d displays there's the HMDs which are head mounted displays right these are the these are the two sort of screens in front of your eyes or virtual reality that's what everybody thinks about but there are those displays like you just talked about in those are holographic displays and you know this actually exists the technology is getting there there's a couple ways in which holographic technology does exist and can work like 3d topographic maps oh yeah yeah but if you're interested more on the technology go go research it a little bit we're not gonna cover that on the show today fair enough we might in the future who knows but those are those are cool to me and then you know you have lasers displays lasers I know the lasers we're nerds here on the common factors well how do you do in laser display is it like plucking at a heart that's like I see like a bunch of different colored lasers and then you plucking it at it to get information I don't understand how lasers work look man they're having like magnets lasers that's all you have to know it's just lasers all right that's fair that's fair that's fair but you know I see what you're saying here about these different things but how in design how can people optimize these things it seems like it's pretty just kind of self-explanatory other than what we said about limitation of technology how can you optimize design for a display right so that's a good question so there has been a lot of research on this topic actually and you know there is a well Wiccans and his colleagues witchcraft not not not witchcraft Wiccans Wiccan not not Wiccans Wiccans wi ck ENS you know I bet I have some sage in the backyard we can start burning if we're gonna talk about this but I didn't know this was gonna be part of design Wiccan all right anyway new agey so so Wiccans who's a researcher and his colleagues they they came up with these thirteen principles of 13 you say I've been sitting on these jokes all day you know what okay no you know what I'm sorry you're starting to convince that you're legitimately starting to convince me that human factors is witchcraft more that I hear about it it just seems like techno man see you know what that might not be one of these days you're just gonna have a head come in here and you're gonna be dressed up like a supervillain you're gonna just start shooting lasers everywhere man how cool would that be for a photo shoot for the five counties we domesticated from Berlin we do a very 80s style yeah because you know it's just bright pinks and oranges I'll put on a mullet for that all right all right let's do it okay 13 principles yeah yeah yeah so the these principles basically they cover different aspects right of of displays right such as like how we perceive information how we think about this information mm-hmm how we sort of attend to different cues of information right and and also how we use our our memory when we're looking at this information okay yeah yeah but these 13 principles that you give to your dark lord - my lord design like what are these things I mean is it kind of like the heuristics idea you know that well no there's ten heuristics yeah so there's well but what are the thirteen principles of display design I mean like how does that work okay so if you want me to actually cover all of these this might be a really long show are we talking two-parter we might have to make this a two-parter ah you know half of our fans are gonna love it and half of our fans are gonna hate the fact that it's a two-party it's like just make a long episode I gotta listen to two episodes and you're gonna spread it out over two weeks are you lazy do you know you can't you have enough material don't you do not want to record next week what's going on hey is that is that no no we're still recording we're still work with we better be we have to I gotta get my weekly Billy fix yeah all right so anyway okay so yeah so two-parter yeah good I'm down with that looks right um it is interesting it is interesting stuff so I'm totally down I'm getting out the monster energy drinks I'm I'm letting some sage I'm setting the mood light and let's do this all right so okay okay so there's these four twos right how how you design for display right so there's uh how we perceive things how we think about things how we attend to different cues and also how we use our memory right aha know that what that boils down to basically is perceptual design principles you have mental model principles principles based on attention and memory but what no I'm kidding I know but I was well played thank you I'm like a chihuahua of the chaingun I'll just make a bunch of jokes until something's funny something will be funny someday so keep trying but um fiving I believe in you yeah okay so let's talk about perceptual principles all right I'm excited to you what is perception I'm asking the deep philosophical thoughts right now Wow yeah perception is anything I can see here touch or taste and the auditory the mental responses that come with it so like this can in front of us I see this colors of the can I perceive what the can is I feel what the candidates cuz it's in my hands that's a monster cuz we're doing a two-parter right yeah okay so you were right on half of that okay um the half that you were not right on was the interpreting it that's that's perception the sensation is seeing it or having the raw signals come into your body right and so that is what we're tapping into for these perceptual principles right so seeing the can right so the first one you want to make the display legible or audible okay like this podcast we need to speak very clearly so that people understand what we're talking about we need to have concise sentences that people can understand very strict diction like 1950s radio news jockeys kind of round the rough and rugged Rock the rude and ragged rascal ran that was impressive I'm impressed I'm legitimately impressed all years of practicing that sucker you've always wanted to do radio huh oh well we can't I can't get on topics but yeah it's like we got a G of radio ah we're gonna have to question Ori that one time I'm writing it down I'm writing down that's right okay great I am excited about this and we have to talk about that little gift he gave me that one time yeah we we it sounds really bad when you say it that way yeah it sounds like I'm I'm smuggling this is a family show drugs yeah yeah okay for America we love drugs don't do drugs stay in school stay clean I respect your elders so yeah you want to make these displays legible audible right and and the reason being right these displays are the ability to actually perceive what they're saying I mean these are kind of self-explanatory right it's critical for designing something that's usable right that's if it's not legible if you can't read it or you don't understand what's going on well yeah then then the operator can't make use of them right right and you know it's it's really interesting because some other things that like yes this sounds really simple make it legible but how do you do that there's a lot of stuff that goes into it right so you got to think of like the contrast of the display the visual angle of where it's at where you're looking at it from the size that it could be on yes what kind of illumination is going on what kind of background noise you got going on if it's auditory you know there's there's just a ton of different factors that go into it and these are the human factors it's all waiting those are the design factors but the human factor is how the human plays into this right this right right right right how do they perceive all this information you have to design around you got there in a roundabout way yes I did I so the next one is avoid absolute judgment limits you don't want to be racist to the machines or anything like that you don't want to say something about the machine before that day yeah Judgment Day you know because we none of us want to be Sarah Connor clinging to a fence while we get vaporized well that's not quite what this one means ah man when are we gonna go there what psychology of psychology manator of let's review the Terminator no no we could do a I'm capturing this i'm kappa no now now they know it's real um we can actually review do a heuristic review on the t1000 i don't think it'll do well today on human factors cast we're reviewing the t1000 is it better than the t 4,000 to 10,000 thank you all right okay so no absolute judgment limits is not terminate right that's what this is is basically saying don't make the operator sort of pay attention to only one factor right so so you want to build redundancy into your design right don't don't make it like don't make it black and white right don't make it like this means one thing and that means another but make it clear there's I know there's a lot that goes into it Wow for something that's supposed to make it clear and concise that's really hard to explain hmm right so don't ask the user AHA to determine the level of a variable so like you know code red on the basis of a single aspect so write code red right okay well if code red is up at the top of a list then you know code red is bad right right right that's why they always when you're trying to enter in your information for like something it'll always come up at red at the top of the page that you forgot to enter in your zip code or this doesn't match up right right and you know basically what this is getting at is don't don't pigeonhole the user into having to discriminate between two things that are really close so if you have Code Red Code Red

like shade of red like code pink oh I just say ho pink kind of white we like you you want it code red code yellow code blue code green you know we run into these problems sometimes in video games too like wait a minute does that thing mean this or does that mean that because like it's no some brains are kind of similar but small and understandable yeah it's not discrete mmm so yeah whenever you're dealing with levels of something right make it make it discrete and distinct so that you can distinguish between the two things okay well that's a lot easier than you started out with yeah get your stuff together roam no Smee and there's a lot here yeah yeah yeah it's easy to over complicate things and you have to remember to there's so much that goes into these that I'm trying to bring it down to a level that someone who's not a human factors practitioner would undergo a ballute someone who hasn't gone to school this is this is for the general audience we have to make it a spy Narine human factors fresheners or just everyone who likes a little tech news right okay so what's next so top-down processing would be the next one uh-huh and this is still in perceptual principles right so what top-down processing is basically exactly that right you you get the signal and then you process it right whereas bottom-up bottom-up is different it's where you think about something and then or you have some some sort of thing in your head and I'm really grossly oversimplifying this but you have an idea in your head and then that molds what you perceive versus you get the signal and then that affects what you are interpreting and I'm I'm very grossly oversimplifying that but that's basically what it comes down to uh-huh and so you know you want to make sure that the signals that the user is getting on these displays is perceived and interpreted based on what's expected from a user's experience right and there's this whole field of user experience there's a lot of UX podcasts out there when I see UX user experience there's a lot of UX podcasts out there that talk about a lot of this stuff but you know if a signal is presented and it doesn't match up with what they're expecting right uh-huh

you might need to sort of present something else to make sure they understand what's going on okay right so so people perceive and interpret these signals according to what they kind of expect on the basis of their past experience right so

like let's think about buttons right so if if this button is pressed on mm-hmm rightly or like let's say like a series of buttons right so all of these buttons on a on a board operator on a board operator control board uh-huh are pressed on and the last one is not lit what are you gonna assume it should be on yeah because everything else is alright yeah yeah so so that's your expectation right and so you want to build upon those you want you want to make a display that's going to be in congruence with what they are expecting so you can make intelligent choices without actually fully understanding exactly what you're doing yeah so kind of like how a fuse box works like you have the on/off switch of it right but if the fuse has been jumped and you need to reset the fuse it's set to the middle so it's like hold on all these users are on except for that ones in the middle so I know that that one is the one that tripped right and if you try to push it to the on it keeps going back to the middle but if you shut it off and then turn it back on it no you know better yeah and it gives you that tactile sensation plus it gives you a sound sensation yeah man I'm learning you're getting it you're getting it my degree is in the mail in the mail any one factors cast University are you may need to make me one now so I can hang it up behind us at our lovely studio all right so next we're talking about redundancy gain uh-huh now this is basically providing the same information twice in different ways hmm so there is a display that you see every single day that has redundancy gain built into it my phone your phone probably has some of that but I'm talking about something even more simple it has three states three states you look at a display that has three states Mike mm you don't own this I I don't own this but you look at it every day I don't own this but I look at this every day ah you're building me a computer no most people own a computer but oh yeah that's true bastard light switch no that's not that's only two you are not close you're getting warmer with light switch I'll tell you it's traffic light oh I see what you're saying okay okay so the idea of redundancy gain uh-huh redundancy gain is presenting information in two ways okay because I see in two ways one it's giving me color coordination and it's also doing it by position of the lights you are yes hi purposely stop there I gave you that and I gave you what this was and yeah right there on you right from the start of this project now we're growing we're growing we're all and again there I could I had trouble even remembering computers as social actors a couple of podcasts ago and now look at me remember computers are social I did

you're playing you're a scientist playing with an erector set and I'm like look what I did with these building blocks Lincoln Logs son hey man that's all good as long as you're learning and we're having fun doing it that's what matters III need my daily dose of Nick alright so next up we have discriminability and this kind of goes with that I'm not a real word is it discriminability discriminability discriminability that's not when you really want to win Scrabble it means the the essence of being discriminable or okay so let me start from the beginning to discriminate something is able to tell it difference between two things right right right to be discriminating has to be able to be discriminated against something else uh-huh discriminable II your sorry yo it discriminable Wow you're making me tongue-tied here discriminability discriminability uh-huh is sort of the trait that that one of these displays must have in order for you to tell the difference between something else I know I looked it up already I just wanted you to go through it you know what it's only fair because I make you sweat sometimes on the show this was getting me back for computers that's a few minutes of my life I'm never getting back back then right so well anyway so yeah you basically want to avoid similarity uh-huh right you you don't want to cause confusion all right for the person right you don't want them to be like ah does that mean this or this you want it to be clear-cut concise and and if it's like right next to something that looks very similar uh-huh don't put it next to that thing that looks similar put it looks next to something that looks different and then you have that redundancy gain if it's in a different place all these things work in harmony together like once you create a display to put all these things together mm-hmm that's when you have something great right and and that's really awesome to do when you're like you're looking at it and you're going know something's just not right it just doesn't have this aspect of it and it's not like we sit there with these lists these are just like guidelines to go off of but you know it's something's just not right and then you move something just a little bit or you organize something in a different way and all of a sudden it just works okay I see what this is going on okay okay so next up we have the mental model principles right so but that was the that was the perceptual principles that we just went through to perceive things okay yeah right and now we're going into mental models do you know what a mental model is a mental model is it's the idea of like people making a connection to one thing or another I would think like like a mental model would B I know an on/off switch right and I mentally know the down is off and on is up right but you don't actively think about like when you flip it down and turn it off that the current turns off you just know that down means off right yeah yeah yeah it's yeah it's basically some sort of explanation of how someone thinks about something right or how something works in the real world and so like for example like how would you imagine uploading our pod our podcast of the cloud works condensation no kidding gaseous form circle of life magic digital pixie fairies that's another kind of science my friend well I would imagine that it goes um uh it probably like cloud service is probably like do you think it's and I think of it like you know what I think it's like movies here's what I think it is I think it's like how the movies say it is there's this huge banks of servers and but I'm but like them and it goes and our our thing kind of goes like a stream from server to server to server to server to server backing around again around again until we access it that's how I think it happens that's a mental model that might not be how it actually happens oh that's how you think it happens and that's how it's represented in your brain right that's how you're actively thinking about these problems so we have to take this sort of thing into consideration right it's it's a representation of what's around you right and and sort of the relationships between things and the various parts of a system they kind of what wait um quick question here about this that just occurred to me yeah why does that matter in my design how something why I think how something works that's a good question let's get into the principle of pictorial realism oh not pectorals like you work on at the gym but pictorial let's be honest here neither of us work on our pecks at the gym how about them glutes get those Gardens all right so no principle of pictorial realism this is basically saying that a picture or a display should look like what it represents so if you think of our podcast going to a cloud mm-hmm like SoundCloud oh I thought what you did there down clouds icon is a cloud and our podcast is stored on the cloud so they are using this pictorial image of a cloud to signify that is where our podcast is being stored on this cloud it's not servers kind of like how Dropbox works they it's a box and there's thin and there's an arrow going into yeah up in the box even though it's a server yeah yeah yeah they're matching it to those mental models right so this is something that UX designers think about yeah okay okay okay human factors engineers UX designers cognitive scientists yeah put some pictures of it that's really what they think about they think about okay how is it supposed to look that's something that goes into it the person who actually makes the pictures would typically be like a visual designer uh-huh see I couldn't do that because everything would look like the side of a panel and very complex and have wings and fancy design things like that I am much more pinky for a stick figure kind of person no well I'm not artistically I wouldn't be that I would be a stick figure type of person but I just think everything looks cooler yeah

anyway so so another example of this that would be like think about sort of a hmm how about your speedometer in your car right yeah when you're when you're cranking something up which way do you crank when I'm going up I crave to the right right to the right yeah so as you're cranking up the speed my knee is going towards the right okay yeah yeah you know so you want to match that with your mental model right righty-tighty lefty-loosey right so yeah you just you want to match these things

it would be sort of in place like like an example of doing this incorrectly would be like the speedometer but up and down and and the reason you wouldn't want to that's why when we look at music levels and things like that it's always a bar that goes up and down in various levels right right yeah instead of left to right because you can understand high and low much better than you can understand you can understand high and low and it's represented vertically rather than when it's represent horizontally and we also use perceptual principles with the color scheme in that same situation yes yeah okay you're getting it you're getting it oh man all right so the other mental model principle is the principle of the moving part uh-huh so this basically says that moving elements should sort of move in a pattern instead of you know kind of on their own and and you want it to move in a way that matches how the user would think it moves in the system right so Dropbox for example again you put a file in the Dropbox and you know if it showed like an animation of the file actually going into a box that would be that would be an example of that but like a good example of this would be to show you know like if let's say you had a display on your car right right that shows you how far like in a Tesla you have how far away from the car in front of you this episode of human factors cast is brought to you by Tesla we hope we hope you on call me wouldn't that be exciting if Tesla was our sponsor Oh wouldn't it be exciting they've Elon Musk called us right now and been like I'm in Ireland right and I'm listening to your podcast and I just loved he's from Ireland right I no no no he's like Dutch I don't know I don't want to make any assumptions about where a lot of mosque is from because he is all-knowing and all-powerful and he knows of this podcast if I get it wrong he's not gonna send me a Tesla for saying this this this podcast is brought to you by Tesla hey you want to just to send you I know okay alright let's so let's say an example for example you're in a Tesla and it has this display that shows you how far behind the car in front of you you are okay now a good example of principle of the moving part would be to show more lines to indicate more distance to the car in front of you then you know less less lines right because less lines less less less distance more lines more distance okay okay kind of like how we do with like backup cameras and parking cameras because we have those two lines that go all the way out and they have like red yellow and green from inside out red yellow and green and the closer you are to a curb or another car it shows you on the lines yeah those aren't moving though so some of them move some of them do yeah that's true basically though you know in that example that I just used the Lions they wouldn't necessarily be moving but the amount would be changing and so that that would sort of like a compound thing yeah kind of okay okay okay well Billy you know what this is me T this is me T I mean we only covered we're only we're only halfway through geez you're right I know what we're getting close to that time I I think that's got to be it for today you know we're tomorrow yeah more next week next week right next week you know we're not gonna take a question today okay that's a shame it is a shame but if you guys our listeners want to be featured on the show we're all over social media mm-hmm comment on our SoundCloud Facebook or Twitter or you can send us an email at human factors cast at with all of your questions all of them all of them be sure to LIKE follow and review us on iTunes the Google Play Store SoundCloud or your favorite podcast directory where we'd love to have that stuff we are all over the place now we're always trying to keep in touch with interesting topics that you guys want us to talk about on the show I've been your host Nick Rome you can find me on LinkedIn comm slash Nick Rome with two O's Billy halls where can they find you can find me on Twitter or steep streaming on YouTube at comstar Klerk thanks again for listening to us here on human factors fast until nice time

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