Say that in order to determine what B is, you analyze A. But then someone analyzes B in order to determine what A is. In my language, we would say that this procedure "begins in the wrong end". What is an appropriate English idiom or phrase here? The only one I can think of now is to say that the procedure has been "turned on its head".

EDIT: I intend to use the appropriate phrase or idiom in a scholarly paper, so it needs to be polite enough for that context.

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    It might rather depend on why you think it's "better" to analyse A to learn more about B, rather than vice-versa. If you think other researchers are mixing up cause and effect, say, that's not necessarily the same as a situation where A and B are mutually interdependent, and you just happen to think it's easier to start by analysing A. Commented Aug 19, 2014 at 20:46
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    I guess the edit about needing a polite term lets out "bass-ackwards".
    – Hot Licks
    Commented Mar 29, 2017 at 22:41

9 Answers 9


The simplest and most direct translation might be "to begin at the wrong end" or "to start at the wrong end". There's no need to get too idiomatic, if you're writing formally, and I believe those phrases would strike a native English speaker as correct in the context you've specified.

  • I like your reasoning. I too was worried that many of the suggestions given in this thread were a bit "too" idiomatic.
    – Sverre
    Commented Aug 21, 2014 at 12:18
  • @Sverre: You asked for an idiom and now you chose an answer you mentioned already in the question. Interesting.
    – ermanen
    Commented Aug 21, 2014 at 14:33
  • @ermanen As the first couple of answers provided were very figurative metaphors, I specified in my question that I was looking for something appropriate in a scholarly paper, and that it could be an idiom or a phrase. I don't see anything wrong in choosing a phrase that's similar to the idiom I know in my own language, as long as native speakers think it's fine. And to be fair, "to start at the wrong end" is also an idiom, even though it's not very figurative or colorful. Which is why it's probably more appropriate in a scholarly paper.
    – Sverre
    Commented Aug 21, 2014 at 15:08
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    @ermanen It was not my intention to look for something that had to be very different from the idiom in my own language (nor did I ask for that). Maybe that's always implied when asking for idioms on this site, but I didn't know that. And finally, the answer is different from what I mentioned in my own question, since the preposition is different. The reason I asked here at all is because googling "begin in the wrong end" gave virtually no hits, but "start at the wrong end" gives lots of hits. So the accepted answer provides an actual English idiom which suits my purpose fine. Is that wrong?
    – Sverre
    Commented Aug 21, 2014 at 15:11
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    @Sverre: Fair enough. Yes it should be "at" instead of "in". Even I couldn't realize :)
    – ermanen
    Commented Aug 21, 2014 at 15:18

There is an idiom that conveys the idea: to put the cart before the horse

  • Fig. to have things in the wrong order; to have things confused and mixed up. (Also with have.)

  • to do things in the wrong order

Source: http://idioms.thefreedictionary.com

Wikipedia says:

The idiom is used in a context which reverses the usual chronological order of A and B.


An informal term, often considered rude, is ass-backward (also ass backwards, and both with and without the hyphen)

the wrong way round; back to front; in the opposite order to what is considered normal [Collins]

A related term that may be considered slightly less rude, and has the benefit of being autological, is bass-ackwards

Ass backwards. The state doing (or having done) something the wrong way. No no dude, you've got the cables plugged in all bass ackwards. [Urban Dictionary]{But also recognized by Oxford Dictionary Online]

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    I intend to put this in an academic paper, so I'm afraid crude expressions like these are out of the question ... :)
    – Sverre
    Commented Aug 19, 2014 at 18:03
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    @Sverre Then perhaps You are placing synthesis before analysis!
    – bib
    Commented Aug 19, 2014 at 18:11
  • I'd be inclined to say "You've got it backwards".
    – user61268
    Commented Aug 20, 2014 at 21:30

If it is indeed logically wrong for person X to analyze B to determine what A is, you can say “X has got hold of the wrong end of the stick”. From wiktionary's entry for wrong end of the stick:

A wrong idea about something, a misconception. As usual, the newspapers got hold of the wrong end of the stick and stated the whole problem in reverse.

You might also say “X's analysis is topsy-turvy”, where the latter phrase means “Backwards or upside-down; disorderly; chaotic”.

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    I wouldn't say that "getting hold of the wrong end of the stick" inherently implies backwardsness. Commented Aug 20, 2014 at 11:21

In certain technical contexts, particularly when it is known that A implies B, and someone relies on that relationship to claim (directly or indirectly) that B implies A, you could use the term "affirming the consequent" or committing a "converse error".

This concept is sometimes extended metaphorically to less formal contexts (i.e when someone hasn't committed an actual logical fallacy, but is still doing something fishy) by softening the language and removing the technical gloss, and saying someone is "begging the question" (though in recent times "beg the question" has started to be used as a synonym for "raise the question", a somewhat sad loss of a useful distinction).


You might say that they're "looking through the wrong end of the telescope"


A West-Country adage:

If I were going there I wouldn't have started from here.

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    actually that started as a joke, the story goes that a man is travelling through rural Ireland trying to get to Cork and is so lost that he pulls over to ask a local for directions. The local responds "take a left, then a right, then... no, wait, you should turn around turn left at the pub and then keep going until... no, actually, if I were going to go to Cork I wouldn't start from here". That may be the origin or may just be an excuse to tell a favourite joke I'm not quite sure any more.
    – MD-Tech
    Commented Aug 20, 2014 at 12:13
  • I work as a web developer, and it regularly applies to changes made to existing projects.
    – AJFaraday
    Commented Aug 21, 2014 at 13:09

"Doing it in reverse order", or "doing it backwards" or similar.

(The first suggestion seems to fit your Step A/ Step B example well)


Nathan Bailey, Dictionarium Britannicum, second edition (1736) has this apt phrase for trying to do something backward:

To flay an Eel at the Tail. That is, to begin a thing at the wrong end. The Fr[ench] say: Brider son Cheval par la Queuë, to bridle a horse by the tail.)

I have never heard anyone use this eel-flaying idiom, but it clearly conveys the idea of making a task much harder by commencing work on it at the wrong end.

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