<p>If understood your question well you are looking for <a href="https://en.wikipedia.org/wiki/Depth_perception" rel="nofollow noreferrer">depth perception</a>:</p>

<blockquote>
  <p>Depth perception is the visual ability to perceive the world in three
  dimensions (3D) and the distance of an object.</p>
</blockquote>

<p>The depth perception is achieved by specific cues in our environment :</p>

<blockquote>
  <p><strong>Perspective</strong></p>
  
  <p>The property of parallel lines converging in the
  distance, at infinity, allows us to reconstruct the relative distance
  of two parts of an object, or of landscape features. An example would
  be standing on a straight road, looking down the road, and noticing
  the road narrows as it goes off in the distance.</p>
  
  <p><strong>Relative size</strong> </p>
  
  <p>If two objects are known to be the same size (e.g., two trees) but
  their absolute size is unknown, relative size cues can provide
  information about the relative depth of the two objects. If one
  subtends a larger visual angle on the retina than the other, the
  object which subtends the larger visual angle appears closer.</p>
  
  <p><strong>Aerial perspective</strong> </p>
  
  <p>Due to light scattering by the atmosphere, objects that are a great
  distance away have lower luminance contrast and lower color
  saturation.</p>
  
  <p><strong>Occultation</strong> </p>
  
  <p>Occultation (also referred to as interposition) happens when near
  surfaces overlap far surfaces. If one object partially blocks the view
  of another object, humans perceive it as closer.</p>
  
  <p><strong>Elevation</strong> </p>
  
  <p>When an object is visible relative to the horizon, we tend to perceive
  objects which are closer to the horizon as being farther away from us,
  and objects which are farther from the horizon as being closer to us</p>
</blockquote>

<p>see the complete list of cues at <a href="https://en.wikipedia.org/wiki/Depth_perception#Monocular_cues" rel="nofollow noreferrer">wiki</a>.</p>

<p>For furter reading see <a href="https://books.google.com.cy/books?id=WBlUgKhMbdsC&amp;printsec=frontcover#v=onepage&amp;q=depth%20perception&amp;f=false" rel="nofollow noreferrer">Visual Thinking: for Design
By Colin Ware</a> </p>

CC BY-SA 3.0
2017-07-26T02:20:44.890Z
Thanks for your response. Unfortunately it is not depth perception what I'm talking about, but it could be somewhat related. I don't know why my previous comment wasn't posted so sorry to respond so late.
Girauder
CC BY-SA 3.0
2017-07-14T08:53:55.003Z
2017-07-14T08:53:55.003Z
DesignerAnalyst
<p>Long comment, so writing as an answer... I have to agree with @StevenJeuris: use context. </p>

<p>For example, you could establish some magnitude scale for a comparison (this is your context), then compare the distance between objects as a percentage of the magnitude. </p>

<p>Which magnitude to use? This is <em>entirely</em> subjective. In human behavior, individuals certainly can and do disagree on whether objects are close or not (depending on the context they are considering). An astrophysicist may consider any object on a single planet "close" to each other, while a microbiologist may consider any separation that can be seen with the naked eye to be "far".</p>

<p>To answer "what parameters do you base the decision on," consider the question "close as compared to what?" For the example of trees above, you may consider it as "close/far, as compared to my distance from the tree," but again, there are more complex pieces (personal history, etc) that also come into play. You <em>could</em> program that (for the astrophysicist, keep the default comparative distance as an interplanetary or interstellar distance), but you'd have to make an active decision regarding the purpose of your program.</p>

<p>Perhaps one other thing to remember: there is no "normal", necessarily. Everyone can look at comparative distance differently, and there isn't much of an objective standard to dictate someones comparison as "right" or "wrong", there is simply what they are comparing to (and then we may be able to get into "correct" and "incorrect" comparative distances).</p>

CC BY-SA 3.0
2017-07-26T02:36:03.270Z
Thanks for your answer! Although it's not exactly what I was expecting, what you say about the "Context" does give me a good insight. I could consider as "context" the distance between a subject and one of the objects, and based on that determine if the other object is close or far away
Girauder
CC BY-SA 3.0
2017-07-13T15:41:59.023Z
2017-07-13T15:41:59.023Z
mflo-ByeSE
<p>Humans have an intuition of when two objects or places are close or far away from each other which is seems to be relative rather than absolute. One might say that Germany is close to France, my house is close to the supermarket, etc., and then say that two plants in the backyard are far from each other.</p>

<p>Even when this is subjective, based on what do we classify two objects as being far, close, or somewhere in-between? Is it just the the size of the objects? what about objects of very different sizes like a house and a pen? </p>

<p>What about the distance from us to the objects? Would we consider two trees to be close when we are very far away, but then consider them far away when we are close to them?</p>

<p>What are the parameters that we base this decision on?</p>

<p>How would a computer classify two objects in such a way that it "mimics" the human decision. </p>

CC BY-SA 3.0
2017-07-12T12:46:53.333Z
Context (as you already highlighted in a couple of examples) ... surely? Not sure what you are hoping to find here, as you already answered it yourself. Try to refine the question to narrow it down. As is, I believe this question is too broad.
Steven Jeuris
CC BY-SA 3.0
2017-07-12T14:43:54.693Z
@StevenJeuris I'm trying to find what parameters should a computer use to answer if two objects are close or far away.
Girauder
CC BY-SA 3.0
2017-07-14T11:15:32.890Z
I'm voting to close this question as off-topic because although this has a cognitive basis, this has nothing to do with Cognitive Sciences
Chris Rogers
CC BY-SA 3.0
2017-07-16T19:55:07.100Z
@Chris I disagree, since it appears that OP is trying to create a cognitive model, which is in the scope of this site
Seanny123
CC BY-SA 3.0
2017-07-25T13:17:04.463Z
I don't understand why this question is closed? The relative nature of the senses is a fundamental property of vision, hearing and touch, and perhaps the other senses too. I would strongly vote to re-open this question.
AliceD
<cognitive-psychology><perception>
Relative distance
Girauder
# Relative distance

(Asked by: username_0 on 2017-07-12)

Humans have an intuition of when two objects or places are close or far away from each other which is seems to be relative rather than absolute. One might say that Germany is close to France, my house is close to the supermarket, etc., and then say that two plants in the backyard are far from each other.

Even when this is subjective, based on what do we classify two objects as being far, close, or somewhere in-between? Is it just the the size of the objects? what about objects of very different sizes like a house and a pen?

What about the distance from us to the objects? Would we consider two trees to be close when we are very far away, but then consider them far away when we are close to them?

What are the parameters that we base this decision on?

How would a computer classify two objects in such a way that it "mimics" the human decision.

**Tags:** cognitive-psychology, perception

> **Comments:**
> **username_1**: Context (as you already highlighted in a couple of examples) ... surely? Not sure what you are hoping to find here, as you already answered it yourself. Try to refine the question to narrow it down. As is, I believe this question is too broad.  
> **username_0**: @StevenJeuris I'm trying to find what parameters should a computer use to answer if two objects are close or far away.  
> **username_2**: I'm voting to close this question as off-topic because although this has a cognitive basis, this has nothing to do with Cognitive Sciences  
> **username_3**: @Chris I disagree, since it appears that OP is trying to create a cognitive model, which is in the scope of this site  
> **username_4**: I don't understand why this question is closed? The relative nature of the senses is a fundamental property of vision, hearing and touch, and perhaps the other senses too. I would strongly vote to re-open this question.  

---

## 2 answers

### Answer by username_6 on 2017-07-13. Score: 2 | Accepted answer

Long comment, so writing as an answer... I have to agree with @StevenJeuris: use context.

For example, you could establish some magnitude scale for a comparison (this is your context), then compare the distance between objects as a percentage of the magnitude.

Which magnitude to use? This is *entirely* subjective. In human behavior, individuals certainly can and do disagree on whether objects are close or not (depending on the context they are considering). An astrophysicist may consider any object on a single planet "close" to each other, while a microbiologist may consider any separation that can be seen with the naked eye to be "far".

To answer "what parameters do you base the decision on," consider the question "close as compared to what?" For the example of trees above, you may consider it as "close/far, as compared to my distance from the tree," but again, there are more complex pieces (personal history, etc) that also come into play. You *could* program that (for the astrophysicist, keep the default comparative distance as an interplanetary or interstellar distance), but you'd have to make an active decision regarding the purpose of your program.

Perhaps one other thing to remember: there is no "normal", necessarily. Everyone can look at comparative distance differently, and there isn't much of an objective standard to dictate someones comparison as "right" or "wrong", there is simply what they are comparing to (and then we may be able to get into "correct" and "incorrect" comparative distances).

> **Comments:**
> **username_0**: Thanks for your answer! Although it's not exactly what I was expecting, what you say about the "Context" does give me a good insight. I could consider as "context" the distance between a subject and one of the objects, and based on that determine if the other object is close or far away  

---

### Answer by username_5 on 2017-07-14. Score: 2

If understood your question well you are looking for [depth perception](https://en.wikipedia.org/wiki/Depth_perception):

> Depth perception is the visual ability to perceive the world in three
> dimensions (3D) and the distance of an object.

The depth perception is achieved by specific cues in our environment :

> **Perspective**
>
> The property of parallel lines converging in the
> distance, at infinity, allows us to reconstruct the relative distance
> of two parts of an object, or of landscape features. An example would
> be standing on a straight road, looking down the road, and noticing
> the road narrows as it goes off in the distance.
>
> **Relative size**
>
> If two objects are known to be the same size (e.g., two trees) but
> their absolute size is unknown, relative size cues can provide
> information about the relative depth of the two objects. If one
> subtends a larger visual angle on the retina than the other, the
> object which subtends the larger visual angle appears closer.
>
> **Aerial perspective**
>
> Due to light scattering by the atmosphere, objects that are a great
> distance away have lower luminance contrast and lower color
> saturation.
>
> **Occultation**
>
> Occultation (also referred to as interposition) happens when near
> surfaces overlap far surfaces. If one object partially blocks the view
> of another object, humans perceive it as closer.
>
> **Elevation**
>
> When an object is visible relative to the horizon, we tend to perceive
> objects which are closer to the horizon as being farther away from us,
> and objects which are farther from the horizon as being closer to us

see the complete list of cues at [wiki](https://en.wikipedia.org/wiki/Depth_perception#Monocular_cues).

For furter reading see [Visual Thinking: for Design
By Colin Ware](https://books.google.com.cy/books?id=WBlUgKhMbdsC&printsec=frontcover#v=onepage&q=depth%20perception&f=false)

> **Comments:**
> **username_0**: Thanks for your response. Unfortunately it is not depth perception what I'm talking about, but it could be somewhat related. I don't know why my previous comment wasn't posted so sorry to respond so late.  

---

