Is there a word or common phrase that means "I know this isn't strictly speaking correct, but beginners should use it as a working model until they are more proficient and then we can discuss why the model isn't quite correct"

Some examples of the concept might be:

  • "An object in free fall will accelerate at 9.8 m/s^2" (only true in a vaccum - experts will recognise that air resistance is a factor, but ok as a working model where you don't need to be more precise)
  • "a computer has a fixed amount of memory" (useful for a beginner, not true because of virtual memory)
  • "in music, a crotchet is always longer than a quaver" (useful for a beginner, not true for an expert due to changes in tempo or pauses etc)

I'm asking because I'm writing technical content - my audience tend to be pedantic about detail, so I can either say "this is a working model etc" at the top (possibly taking time to define the phrase first), or pepper my writing with "this is only true as long as you don't consider xyz" which tends to make it overly verbose and harder to read for a true beginner who won't have any idea about the hidden complexities yet.

Note that I've tagged as single-word-request or phrase-request because the answer could be either, for example I'd like to be able to say "For the purposes of this document, I'm going to use a XXX model to make my writing clearer - experts will recognise that there are things that are not quite right, but that are nonetheless useful to understand the concept"

  • If you have an answer, put it in the answer box where it belongs, not in the comment box masquerading as a comment.
    – tchrist
    Dec 4, 2022 at 23:34

21 Answers 21


For completeness, a phrase used for this sort of thing should be mentioned:


A lie-to-children is a simplified explanation of technical or complex subjects as a teaching method for children and laypeople.


A “lie-to-children” is a statement which is false, but which nevertheless leads the child’s mind towards a more accurate explanation, one that the child will only be able to appreciate if it has been primed with the lie.

[The Science of Discworld by Terry Pratchett, Ian Stewart and Jack Cohen, via the Lspace wiki]

That said, the phrase doesn't quite match the given example sentence, and for people who aren't already familiar with the concept, the use of the word "lie" would probably be offensive, as would the implication that they're "children". (Though neither are intended as pejorative in this sense.) -- But I mention it because it exactly encapsulates the precise idea you're going for.

  • 2
    I've used the similar phrase "a lie we tell freshmen". I certainly use "lie" by itself in this context "remember I said X? Well, that was a lie. The actual rule is...". Dec 3, 2022 at 22:17
  • 5
    I've never heard this phrase, ever (AmE, northeast US), in my 41 years of vague memories of people talking.
    – Jason C
    Dec 4, 2022 at 20:01
  • 2
    This is a good phrase in certain subcultures, but outside those circles it’s not widely known, in my experience, and can easily be quite badly misunderstood — taken as patronising or even insulting to the audience of the “lie”. By contrast, phrases like first approximation and rule of thumb are more widely understood, and at much less risk of serious misunderstanding. So while I like this phrase in the right context, I would strongly recommend those over it for the purposes the OP describes.
    – PLL
    Dec 5, 2022 at 12:06
  • 2
    @JasonC xkcd.com/1053 But also probably SE has a higher than average percentage of Discworld readers. Dec 5, 2022 at 15:45
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    @PLL Using a loaded word like "lie" is of course intentional here; it's a shocking headline (or clickbait, if you like) that makes the audience want to know more. "What?! How dare you lie to a child! Explain yourself!" Certainly you could divide up lies-to-children, lies-to-freshmen, lies-to-noobs, and so on, but the use of 'lie' is part of the point. Dec 5, 2022 at 16:12

Perhaps "heuristics" or "rules of thumb" are what you are looking for. They are basically enabling techniques that get people started on a problem or activity, though strictly speaking are flawed or untrue.

Merriam-Webster defines "rule of thumb" as:

A general principle regarded as roughly correct but not intended to be scientifically accurate.

  • 5
    heuristics doesn't imply that its discarded. someone proficient might still use heuristics even if they know of a better method, but the better method isn't always available or feasible.
    – chiliNUT
    Dec 4, 2022 at 20:51
  • 1
    I agree with @chiliNUT. A heuristic method does not necessarily "get people started on a problem or activity" nor is it necessarily "flawed or untrue". Dec 5, 2022 at 5:00
  • I agree that heuristics can be just a higher level description of a phenomenon, say "the thermometer knows the temperature of my room", and hence not necessarily flawed. It may be just incomplete.
    – Berry Guo
    Dec 5, 2022 at 9:58
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    @chiliNUT: True; but while OP’s title mentions concepts discarded later, all their examples are things that are certainly not discarded as understanding progresses, just refined. An expert would still think of them as true to a first approximation, and retain them as rules of thumb.
    – PLL
    Dec 5, 2022 at 12:12
  • 1
    I think this is a good answer in terms of English use, but this is actually for a computer science audience, so heuristic conjures up a different connotation. With reference to the examples, to explain the real use would be pages and pages of explanatory text so I've simplified them. Almost a good example of the problem at a meta level!
    – Chris
    Dec 5, 2022 at 13:28

A common qualification I hear is to a first approximation, as in

To a first approximation, an object in free fall around earth will accelerate at 9.8 m/s2.

  • 4
    Used as a noun phrase, one would call such a concept a "first-order approximation." Dec 4, 2022 at 17:34
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    @BetterthanKwora yes, though "first-order approximation" is borrowed from perturbative calculations in HEP, where it does have precise mathematical meaning, so if your doing technical writing you need to be aware of that.
    – Clumsy cat
    Dec 4, 2022 at 21:26
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    @Clumsycat I'm genuinely curious about your comment. Has "First-order approximation" a specific meaning in high-energy physics that is different from the meaning I'm used to, in all of mathematics and physics, where "first-order approximation" relates to the number of terms kept in a Taylor series?
    – Stef
    Dec 5, 2022 at 12:51
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    @Stef Also (possibly by analogy) the number of terms kept in any series, provided it converges quickly enough for that to be useful.
    – wizzwizz4
    Dec 5, 2022 at 19:27
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    @Stef Indirectly, yes. The concept it captures is the terms having more influence on the result than those past the first term of one exspansion. Unfortunately this can include things from more than one expansion and also things that aren't pertubative at all. Tbh, I've not don't theory in a while, so I think you could get a better definition from someone else on this site.
    – Clumsy cat
    Dec 5, 2022 at 23:46

The string rudimentary model has reasonable currency in 'the literature':

The term 'string' is used above as there might be debate over whether this is a fixed phrase (a true term) or a moderately strong collocation (it's certainly more coherent than a free combination: Google 2-grams). The definitions of rudimentary are appropriate:

rudimentary [adjective]

1: consisting in first principles ...

2: of a primitive kind ...

3: very imperfectly developed or represented only by a vestige ...


The term toy model is also used:

  • In the modeling of physics, a toy model is a deliberately simplistic model with many details removed so that it can be used to explain a mechanism concisely. It is also useful in a description of the fuller model. ... An analogous example of an everyday mechanism is often used for illustration.
  • In "toy" mathematical models, this [simplifying] is usually done by reducing or extending the number of dimensions, or reducing the number of fields/variables or restricting them to a particular symmetric form.
  • In Macroeconomics modelling, [toy models] are a class of models, some maybe only loosely based on theory, others more explicitly so. But they have the same purpose: they allow for a quick first pass at some question, and present the essence of the answer from a more complicated model or from a class of models. For the researcher, they may come before writing a more elaborate model, or after, once the elaborate model has been worked out. Blanchard's list of examples includes IS–LM model, the Mundell–Fleming model, the RBC model, and the New Keynesian model.

[Wikipedia; tidied and otherwise adjusted]

'Dumbed-down' and 'oversimplified' increasingly convey an assessment that the model shouldn't even be considered as a stop-gap.

  • I think this is the best 'formal' answer and would suit OP's technically pedantic audience best. Instead of 'toy model' however, I would suggest 'model - not to scale' for the same reasons as 'dumbed-down' should be avoided.
    – mcalex
    Dec 5, 2022 at 4:14
  • Certainly a very good answer for me, but just marginally beaten by the accepted answer because that got me to the exact answer I'd heard previously. I'm going to try using this one too though so will see if it resonates better with my audience, thank you!
    – Chris
    Dec 5, 2022 at 13:31

I think the word simplified would work very well:

For the purposes of this document, I'm going to use a simplified model to make my writing clearer.

In my experience, the phrase "simplified model" pretty much always refers to a model which is less accurate than whichever model it was simplified from. If the model were equally accurate, it would be described as "simpler," not "simplified."

Another potentially useful phrase is simplifying assumption:

For this problem, we will make the simplifying assumption that there is no air resistance.

  • Simplified is excellent when introducing it. When it no longer meets the need and you have to dive into details, you would then describe the simplified model as a crutch.
    – Ben Voigt
    Dec 5, 2022 at 19:27


You are talking about pedagogy, the study of learning, and in this context the term "instructional scaffold" is used.

This adopts a metaphor from building, in which scaffolding is a temporary structure that is used to enable the construction of a building, but is then removed.

Similarly, in pedagogy, scaffolding is a concept that is learnt to allow for contextual understanding at a higher level.

This is discussed in the Wikipedia article Instructional Scaffolding, and is due to Vygotsky's notion of Scaffolding in the zone of proximal learning


Training wheels is used as a metaphor for that in American English. Merriam-Webster (the source of all the quotations in this answer) doesn’t list this as a definition, but all but one of its examples use it in this metaphorical sense instead of the literal ones (an extra pair of stabilizing wheels on a child’s bicycle, removed when they learn to keep their balance).

Even the humble condominium, which once was sort of like a starter house on training wheels, is going for astronomical sums in Southern California’s luxury buildings.

Mental health, especially for young people, was still very much on training wheels.

A more straightforward word for what you’re going for might be, introductory, in the sense of:

of, relating to, or being a first step that sets something going or in proper perspective

Or elementary:

of, relating to, or dealing with the simplest elements or principles of something

Or rudimentary:

: of a primitive kind


The listed examples are all approximations of the actual thing.

Collins Dictionary defines approximation as:

An approximation is a fact, object, or description which is similar to something else, but which is not exactly the same.

That is a fair approximation of the way in which the next boss is being chosen.

  • 1
    "All models are flawed; some models are useful."
    – user888379
    Dec 3, 2022 at 15:03

It's not a single word or phrase, but I like the way Donald Knuth words this in his TeXbook:

Another noteworthy characteristic of this manual is that it doesn’t always tell the truth. When certain concepts of TeX are introduced informally, general rules will be stated; afterwards you will find that the rules aren't strictly true. In general, the later chapters contain more reliable information than the earlier ones do. The author feels that this technique of deliberate lying will actually make it easier for you to learn the ideas. Once you understand a simple but false rule, it will not be hard to supplement that rule with its exceptions.

  • 1
    Hello and welcome to ELU. While this is a relevant article, I for one do not see how this is an answer to the question.
    – NVZ
    Dec 5, 2022 at 9:40
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    In the stackexchange format of answering exactly the question I think this isn't the best answer, but it is a good example of exactly what I'm trying to achieve.
    – Chris
    Dec 5, 2022 at 13:41

useful fiction - Something known to be false, but treated as true because of its usefulness.


  • "The rule of law in our country is a useful fiction."
  • "In order to understand the orbits of the planets, we lean on the useful fiction that the sun does not move."

Your examples are generalities


generality, n.

1.a. The fact or quality of being general (in various senses); generalness, imprecision

1968 Brit. Jrnl. Psychiatry 114 1064/1 Early learning may be characterized by generality rather than specificity.

2.a. [...]a general point, principle, or law; (in later use chiefly) a general proposition or statement, esp. one regarded as excessively broad or sweeping. Usually in plural.

1996 Church History. 65 664 A certain type of person wants broad generalities about a historical period, uncluttered by oddities, exceptions, or messy details.

"All generalities are false, including this one."


One phrase you might use is as a rule, which indicates that what you're saying is often/usually true, but not always.

For variety, you might also use some of its synonyms: generally, mainly, normally, and similar.

These are short and unobtrusive, and so won't detract from your main point, while still indicating to anyone paying close attention that it shouldn't be understood as universal.


I like the answers which are rooted in "simple."

I think I'd probably phrase it as "here, we'll consider this simplification of X (the matter at hand) for the purpose of focusing on aspect Y of it."

Making clear that it's a simplification helps to avoid misleading, I think, and explaining the purpose can inspire further audience insight and make them feel as peers rather than just receivers of information.


I have often referred to such answers in academic circles as 'placeholder' explanations. The idea being, that it will do the job for now, but it will need to be replaced/upgraded in the future. However, I have no idea whether I hoovered this up from someone else or borrowed it from another field, or whether anyone else uses the term (I haven't been paying attention).

I would have put this as a comment, where it belongs, but I can't.


What about stepping stone?


stepping stone, n.

1 : ...

2 : a means of progress or advancement

a stepping stone to success

But now many more see a political job as a stepping stone to money, power and influence. -- Barbara Gamarekian

Each person I talked to was to be a stepping-stone to the overall plan. It was my job to educate them so they would take their natural places in the plan. -- Jane Smiley


I've seen this referred to as a bootstrap concept in an analogy to the code that runs on a computer that sets it up for the more sophisticated OS to be started up, and is then discarded. Unfortunately, I haven't found any mention of that term in this context, which makes me think it might have been a quirk of one of my teachers that others picked up.


I think I've heard it referred to as a first order strategy in learning video games. It's essentially the most straightforward solution you can come up with given an early knowledge and understanding of the problem. With further understanding you're supposed to come up with other strategies that are better tuned to the parts of the system you didn't know about when you started if sometimes less tuned to the obvious 'easier' parts.


I'm pretty sure that's usually just called "simplification".

You want to write:

"For the purposes of this document, I'm going to use a XXX model to make my writing clearer - experts will recognise that there are things that are not quite right, but that are nonetheless useful to understand the concept"

So you can say:

"For the purposes of this document, I'm going to simplify some of the more complex topics. Experts will recognise that there are things that are not quite right, but that are nonetheless useful to understand the concept."

I think it's generally understood that when something is simplified, a certain amount detail and specificity is lost.

Furthermore, if you're only doing this in a small handful of areas in your document, rather than stating it up front, you could just state you are doing this in the places you are doing it, using wording appropriate for those individual contexts.

More niche phrases have a risk of being not understood at all, or just seeming weird. Also there's a bit of irony in making an explanation of simplification overcomplicated.


So many fantastic answers already. I hope you don't mind me adding two more word suggestions, which I believe would answer well what you are asking about.

One word I've yet to see suggested is "placeholder", as in:

"This is a placeholder understanding." "Gravity and acceleration can serve as placeholders for each other when teaching mechanics to first time learners."

A "placeholder concept" can be labeled as such to indicate that it is to be used temporarily in place of another.

Another helpful word might be "intermediary", which shares similar nuance with the "stepping stone" suggestion made by an earlier commenter. One example:

"The intermediary understanding of gravity being simply 10m/s^2 can be a useful one, that enables learners to more readily absorb the concept, and then later on, replace their initial, rough understanding, with one that is, while more accurate, also more complex."

As someone coming from the field of education, I would second what others have said regarding pedagogy - The nuance of approximations and what role/function they serve is, in my opinion, fundamentally different from that of what "placeholder concepts" or "intermediary concepts" (as I am using the terms here) would indicate. For example, in the case of "approximations", "rules of thumb", and "as a rule", the concept at hand may or may not be transitional, used as scaffolding, and, also, may or may not come prior to the more complex, more accurate, or more advanced concepts. They may simply be a means to an end, and not something that is to be used initially and then cast aside.

I found the poster's question to be wonderfully nuanced - I hope that my nuanced answer proves to be helpful 👍🙂


Given the context you described, it sounds like you're looking for a word/phrase that will help you make progress on a logical path while cutting through the friction of pedantic detail and edge cases.

In the domain of logic, premise is a commonly used term:



a proposition supporting or helping to support a conclusion

It can be applied to your examples in template format (which can be helpful for defining automatic/intuitive speech patterns with practice):

  • Given the premise that [description], [conclusion supported by the premise].

  • Given the premise that an object in free fall will accelerate at 9.8 m/s^2, it will never reach the speed of sound.

  • Given the premise that a computer has a fixed amount of memory, it can only store a finite amount of data.

  • Given the premise that, in music, a crotchet is always longer than a quaver, more of the latter will be needed to fill the space of the former.

However... I don't think formal terminology is always needed: you need only to assert the premise as the foundation of your statement: "Given that [x], [y]..." — given (as an adjective) is really the key word above, but you requested a "formal" term.

  • 2
    I’ve always heard premise in the sense of “assumption” or “axiom,” not with the meaning given here.
    – Davislor
    Dec 4, 2022 at 17:11
  • ^ @Davislor Thanks for the feedback. Was there something in my answer that you thought didn't reflect your experience — somewhere that assumption couldn't be substituted in the places where I used premise?
    – jsejcksn
    Dec 4, 2022 at 17:47
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    The connotation doesn’t fit here. A premise is not something that you discard when you become proficient. There might be some context where it makes sense to use the word for one of those, but the word itself does not convey that meaning.
    – Davislor
    Dec 4, 2022 at 22:35
  • I like the answer here to an extent, but I think I'd still be very verbose if I did this. My examples above were very simple compared to the actual material, so if I don't call out at the top I end up with "Given the premise that [20 pages of material] [1 page conclusion]". My premise will be written up somewhere, just that it really clutters the content when done inline.
    – Chris
    Dec 5, 2022 at 13:37

For the most part
As a general rule
With some exceptions

I liked simplified, perhaps w/o ‘over’

Good question, btw.

  • 1
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