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A graph, a chart, and a plot can all refer to the same thing. Is there any even somewhat consistent distinction in these three words?

(I mean, in this particular sense of the words; it is not relevant that a chart is also a nautical map, a plot is also a scheme, and a graph is also an unrelated mathematical object.)

  • If you're happy to say they can all refer to the same thing, surely it doesn't make sense to ask us to tell you why you're mistaken. You presumably learnt to accept these words as potential synonyms by noticing how they are used, so it should be obvious there can't possibly be a reliable distinction. If there is a potential distinction, people ignore it anyway, so it wouldn't be reliable. – FumbleFingers Sep 23 '11 at 12:35
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    @FumbleFingers that takes the prize for "Most Barely Comprehensible Rant". Thus far. – JeffSahol Sep 23 '11 at 13:05
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    Notwithstanding my comment above, I didn't vote to close. It's true each term can be looked up individually, but dictionaries are not usually good at explaining the subtleties of distinction between overlapping meanings such as this. – FumbleFingers Sep 23 '11 at 13:12
  • @Jeff: It wasn't intended as a rant. I think the question is perfectly okay apart from the fact that OP asks for a reliable distinction. Clearly this is a case where there is overlap, as Guffa's excellent answer points out. – FumbleFingers Sep 23 '11 at 13:14
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    The thing that really throws a great big monkey wrench into this is that "graph" also has a mathematical meaning of a structure used to model pairwise relations between objects using nodes connected by edges. In this context, a tree is a kind of graph, so the tree in an Org Chart is actually a(n) (acyclical) graph. – Michael Apr 12 '18 at 17:59
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The terms partly overlap, at least if they are used somewhat loosely, and in that overlap there isn't really any difference.

A graph is a diagram of a mathematical function, but can also be used (loosely) about a diagram of statistical data.

A chart is a graphic representation of data, where a line chart is one form.

A plot is the result of plotting statistics as a diagram in different ways, where some of the ways are similar to some chart types.

So, a line chart could be called a graph or a plot, while a pie chart is neither a graph nor a plot. A scatterplot is a chart but not (strictly) a graph, but the purpose of a scatterplot is to determine if there is some relation that can be expressed as a function that then naturally can be drawn as a graph.

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    Perhaps some enterprising soul here on EL&U might care to make a Venn diagram of these three words, with each word represented by a circle with diameter proportional to its relative frequency of use in the context of diagrams. It might be interesting to debate where the circles overlap, and what kind of diagrams fall into each overlapping area. Specifically, the position of that chart itself! :) – FumbleFingers Sep 23 '11 at 13:08
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    "Pie graph" is a common term in AusEng at least. Google confirms lots of results... – curiousdannii Sep 7 '15 at 13:29
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    @curiousdannii: You can call a pie chart a pie graph, but it's still not a graph, it's a chart. – Guffa Sep 7 '15 at 13:43
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    @curiousdannii: Using a word in an expression doesn't change the meaning of the word itself. Using pie graph doesn't change then meaning of graph, just like using horse shoe doesn't change the meaning of shoe. – Guffa Sep 7 '15 at 14:02
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    @Guffa It is meaningless to talk about the meaning of words without a context! All words only have contextual meanings. The issue is whether certain expressions have the same sense as others (perhaps with different connotations) or whether they have distinct senses. I don't think there's reason to consider a "graph" where the equation is derived from the data to have a separate sense to a "graph" where the points are derived from an equation. So I'd say they have the same sense, with largely the same connotations too. – curiousdannii Sep 7 '15 at 14:36
19

Chart and graph are essentially synonymous, but there are some cases where one is preferred over another. This Google Ngram "chart" shows their relative uses:

An Ngram chart showing the relative occurrences of pie chart,pie graph,bar chart,bar graph,line chart,line graph

From this we can see that "bar chart" and "bar graph" are used about as much as each other (and have been since the early twentieth century). "Line graph" is strongly preferred over "line chart", and "pie chart" is strongly preferred over "pie graph" (though in my own AusEng I think "pie graph" feels more natural.)

Plots are different. We make plots out of points, and for something to be a plot, both axes must be continuous. For example, you can make a plot of the height vs. weight of a population, but not the height vs. species, because species are discrete; you can't plot a point halfway between a cow and a chicken. So I'd say that plots are a subset of charts/graphs.

A scatter plot of height vs. weight
(source: ablongman.com)

  • Thanks! While I find your answer plausible, would you happen to have any sources for the claim that “plot” is about points in particular? – Kevin Reid Sep 7 '15 at 14:35
  • @Kevin, no just native speaker intuition. I might be able to find something tomorrow. – curiousdannii Sep 7 '15 at 14:38
  • Quite late to this party, but wouldn't a boxplot defy the two continuous axes rule? – Minnow Oct 18 '16 at 17:04
  • @Minnow true, but that's not a normal plot. Derived words usually have a shift in meaning. – curiousdannii Oct 18 '16 at 21:40
  • There seem to be a number of plots listed on wikipedia that do not have only continuous variables. en.wikipedia.org/wiki/Plot_(graphics) – jamie Aug 15 '17 at 19:32
11

In my professional and academic writing experience, I have never encountered a style guide that defines rules for these words.

I am Australian, an engineer (former) and a mathematics teacher and I consider the following to be best practice when writing and teaching.

  • graph – when a line is drawn (of a function/formula or of continuous data).
  • chart – when other shapes and symbols (e.g. bars) are used to represent data.
  • plot – when points are marked on a coordinate system.

Therefore…

  • bar chart
  • pie chart
  • line graph
  • scatter plot

I “teach” this but wouldn’t enforce it.

The etymology of the suffix -graph supports my practice. Scratching with a stick produces a line. But could also produce a pictograph, figure, diagram etc.

The etymology of both chart might support my practice, in that it is derived from words meaning “map”. A map is a pictorial or symbolic representation.

The etymology of plot might support my practice. Areas of land are typically divided into square or rectangular “plots”. Rectangular areas correlate with the notion of coordinates (sides of a rectangle). Furthermore, variations of plot in other languages typically mean marking points on a chart.

Other supportive uses…

  • A seismograph graphs continuous earthquake data.
  • A navigator plots a course on a nautical chart/map using a parallel plotter.
  • A phonograph produces sound when a needle (stylus) traces over the continuous etch on the cylinder.

The word photograph seems to deviate, unless you imagine that it’s a new way to “draw” with light, the old way being with a pencil on paper.

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    I think that the first half of the above is sensible, useful and will not lead to much confusion below university level. A complication is that the definition of graph in advanced mathematics is much broader: 'In mathematics, and more specifically in graph theory, a graph is a structure amounting to a set of objects in which some pairs of the objects are in some sense "related." ' {Wikipedia}. And a problem with what follows is that arguing from etymology as opposed to from accepted modern usage is the 'etymological fallacy'. – Edwin Ashworth Oct 18 '16 at 13:02
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    @EdwinAshworth As far as I know, there is no usage of “graph” which includes both graph-theoretical graphs and “graphs of a function”. – Kevin Reid Oct 18 '16 at 16:20
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    @EdwinAshworth I'm the OP and I disagree with you. – Kevin Reid Oct 18 '16 at 16:54
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    @KevinReid it's interesting to get a new answer to a 5-year-old question, isn't it? :-) – Hellion Oct 18 '16 at 16:58
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    Like this answer. Very simple to understand. – Karl Morrison Jan 4 '18 at 15:41
5

Here's a quote from a book called "Basic Allied Health Statistics and Analysis"

A chart illustrates data using only one quantitative coordinate. Charts are most appropriate for quantitatively comparing discrete categories or groups of data. The most common charts are column, bar, line and pie charts. [...] A bar chart is particularly useful for displaying data such as gender, ethnicity, occupation, types of discharges, and treatment categories. Bar charts are appropriate for displaying categorical data. Bar charts compare categories or groups using some quantitative measurement.

A graph is a method of relating one qualitative [I think this a mistake, and it's meant to say 'quantitative'...] variable to another quantitative variable, usually time. The most common graphs are histograms and frequency polygons. [...] Quantitative continuous data are displayed via a graph. The two most commonly employed graphs are the histogram and the frequency polygon.

So it seems charts are for when there's one qualitative variable (such as type, preference, or gender) and one quantitative variable (such as time, age or amount). These include pie charts and bar charts. Whereas graphs are for when you have two quantitative variables.

  • Which country ? – Pacerier Jul 6 '17 at 6:27
  • The book was published and printed in the USA – Paul Jones Jul 6 '17 at 10:08
1

Chart and graph are not synonymous.

Consider an Eye testing Chart for example - there is no graph on that.

Consider a Pie Chart - there is no graph on that either.

Consider a Look-Up Chart - there is no graph on that.

Consider a Heat Map - that is also a type of Chart.

A graph can be ON a chart though, hence a bar graph can be a line chart.

  • 'Chart' and 'graph' are synonymous. Check the standard definition elsewhere on ELU: 'synonymous' does not mean 'interchangeable with little or no change in meaning in all usages'. – Edwin Ashworth Oct 18 '16 at 12:53
0

A plot would apply to line charts, with plotted points. A chart could arrange the data in columns, rows, pie shapes, etc., and plots. Graphs are synonymous with charts, though i would reserve "chart" for more plain depictions and call data arranged in columns of kittens "graphs" (though that's just my style choice).

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    I'm intrigued. What are columns of kittens? – FumbleFingers Sep 23 '11 at 12:56
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    @FumbleFingers my guess is that it would be something you would find at graphjam.memebase.com – JeffSahol Sep 23 '11 at 13:03
  • @Jeff: I did a search for "kittens" there, but it didn't have any. Are you thinking of those spam emails that say "Send me money, or I'll drown a kitten?". Which presumably could have an attached chart showing how many kittens the spammer has drowned recently because people failed to cough up. – FumbleFingers Sep 23 '11 at 13:19
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    @FumbleFingers No, I was just guessing about that site. But a quick google search did turn up this gem: xkcd.com/231 – JeffSahol Sep 23 '11 at 13:26

protected by user140086 May 11 '16 at 5:31

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